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Video: Scouting Vegetable Crops: An Introduction for Farmers

lun, 2017/06/12 - 18:35

eOrganic author:

Carmen Blubaugh, Washington State University

This eOrganic video on scouting vegetable crops was created by members of a project of the USDA National Institute of Food and Agriculture, Organic Agriculture Research and Extension Initiative (NIFA OREI) entitled Biodiversity and Natural Pest Suppression (BAN-PestS). 

Video Transcript Introduction

What was the last crop you lost to a pest? When did you realize you had a problem? Many times we don’t know there is a problem until we are up close and personal with a crop. All too often that is at harvest.

Scouting is the routine monitoring of pest pressure in a crop. A scouting routine can help you identify problems in your field before they get out of control. In this video we will scout for cabbage aphid in brassica crops in the Pacific Northwest. However, the scouting principles and tips can apply to any crop or region.

What is Scouting?

Scouting is a systematic way to assess the health of your crop and threat of pest outbreaks without examining every plant. Scouting relies on sampling a subset of the field to collect data you can use to make informed management decisions. Scouting can reduce your inputs and crop losses, saving you money.

There are various tools used in scouting. The tool you will use depends on the crop and pest. Many pests must be trapped to monitor while others, such as cabbage aphid, can be observed on the crop without trapping. In this video we focus on visual observation, but many of the principles of scouting we cover will apply regardless of the scouting tool used.

To begin a scouting routine, start by researching the pests you are likely to observe and the corresponding beneficial insects. This information will help you identify which scouting tools are appropriate and when to begin scouting. Numerous extension resources are available that describe the community of pests associated with a particular crop in your area.

Scouting 101: Before Entering the Field

When you arrive at the field, commit your attention to scouting. Focus is required to capture signs of pests. First, make observations about the entire field. Look for areas that appear stunted or have a color variation. Notice any unique geographic features, such as a depression. These areas may have higher pest pressure. You will want to visit these areas.

Select a path through the field that will allow you to collect a random yet representative sample. One method is to travel through the field in a "w" pattern, selecting plants to sample randomly along that path. Adjust your path through the field to ensure you visit areas you have identified to be at higher risk for pest infestations. Record your path through the field so that on your next visit you can scout a different route. Each scouting trip, you will select a different random sample. On each scouting trip you may want to visit areas you suspect to have growing pest populations in addition to your random sample.

In the Field

When you reach your first sample, assess the plant overall and then start looking at the individual leaves. Look at both young and old leaves, and don’t forget to search both sides of the leaf. You will want to remove a few leaves for closer observation. Now look at any buds, flowers, or fruit. Depending on the potential pest, you may even use your harvest knife to cut open the stalk or unearth the plant so you can see the roots.

Record your observations and a numeric assessment of the pest. For example, a numeric assessment of cabbage aphid pressure is the average number of aphids per leaf. Select three leaves from different parts of the plant and record the number of aphids and aphid predators per leaf. Repeat for ten plants.

You will follow the same procedure each time you scout, but vary your path through the field and which plants you sample. Standardizing your collection method is necessary to accurately track pest pressure over time.

Calculate the average number of aphids and predators per leaf. Reviewing these averages from visit to visit allows you to determine whether or not the pest pressure is increasing, or if beneficial insects are effectively managing the pest. This information will allow you to determine if and when you need to take action to control the pest, in other words, your action threshold.

Your action threshold is the point at which you’ll experience economic loss if control measures are not pursued. Your action threshold depends on the cost of controlling the pest, the effectiveness of your control measure, the value of your particular crop, and the potential for the pest to cause damage that will impact your ability to sell the crop. These factors vary for different crops. For instance, tolerance for aphids may be higher on kale than broccoli since aphids can get into broccoli heads where they are protected from insecticide applications.

Action thresholds also change over time, as markets fluctuate. Ask your local extension educator for help identifying a recently published action threshold for your region and crop. Keep in mind that action thresholds are usually calculated without considering biological control by beneficial insects, and you may want to adjust your action threshold if you observe high rates of natural pest suppression.

Developing your Scouting Routine

Farming is a demanding occupation. To make sure scouting gets done, it is best to make scouting a habit. For instance, you could dedicate lunchtime Tuesday to scouting a few fields. Keeping a bucket of scouting tools easily accessible can help facilitate regular scouting. Must-have scouting tools include a pencil, paper, clipboard, tally counter, and camera.

Pest emergence and growth are each temperature-dependent, and vary with each crop. Check local extension resources to determine approximately when pests in your crop system emerge, and initiate your scouting routine accordingly.

Scouting is an important practice to do on your farm that will definitely pay off. Check out the Pacific Northwest Insect Management Handbook for up-to-date information on crop specific pests. There, you’ll find examples of action thresholds, local emergence times and other resources to help you prepare for and avoid pest outbreaks on your farm.
 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 22209

Video: Growing and Dehulling the Ancient Grains Einkorn, Emmer and Spelt

ven, 2017/05/26 - 15:20

This eOrganic video was created by members of a project of the USDA National Institute of Food and Agriculture, Organic Agriculture Research and Extension Initiative (NIFA OREI) entitled Value Added Grains for Local and Regional Food Systems. Information was provided by Elizabeth Dyck of the Organic Growers Research and Information Sharing Network (OGRIN), Frank Kutka of the Northern Plains Sustainable Ag Society (NPSAS), and Steve Zwinger of North Dakota State University.

Video Transcript

The ancient hulled wheats spelt, emmer, and einkorn are sought by consumers and chefs alike for their distinct flavor, nutritional properties, and the intrigue of eating a meal that has sustained humans since ancient times.

Einkorn, emmer, and spelt differ from modern wheat in that they largely do not thresh free of their hulls in the combining process. An additional step called dehulling is needed to remove hulls.

Chapter 1: Why Grow These Ancient Hulled Wheats?

Through direct marketing, farmers are able to sell wheat kernels and flours from these hulled wheats at a high price per pound to chefs, bakers, and consumers. Additionally, hulled wheat still in the hull can be marketed as animal feed, while empty hulls can be sold as animal bedding.

The hulled wheats also have characteristics that make them highly compatible with sustainable and organic production.

The hulled wheats have traditionally been grown under lower fertility conditions than modern wheat. In fact, high nitrogen fertility can cause lodging in these crops. Although more research is needed, a good rule of thumb is to plant einkorn and emmer with no more than 50%–75% of the nitrogen required for modern wheat. Winter spelt can be fertilized as winter modern wheat without the additional spring topdressing.

The hulled wheats also show tolerance to environmental stresses. Winter spelt has shown cold tolerance, and some einkorn varieties have salinity tolerance. Emmer tends to be more drought tolerant than modern wheat, and spring emmer more competitive against weeds. Emmer germplasm also contains many genes that are valuable in breeding for disease resistance.

In terms of production, spelt yields in the hull are comparable to or slightly lower than that of modern wheat. Recent research on spring emmer and einkorn suggests that yields can vary by location and management. In North Dakota, research shows that spring emmer and einkorn yields in the hull can be higher than modern spring wheat yields. In contrast, in research trials conducted in New York and Pennsylvania, yield of spring emmer and einkorn in the hull varied from 35%–93% of modern spring wheat.

Chapter 2: How to Grow Hulled Wheats

As with modern wheat, there are spring and winter varieties of spelt, emmer, and einkorn. A good starting point to grow hulled wheats is to use best management practices for modern wheat in your region, including good seedbed preparation, timely planting, and timely harvest to preserve grain quality. These hulled wheats tend to be taller and have higher rates of lodging than modern wheat. In addition to avoiding excessive nitrogen, to reduce lodging use lower planting rates for emmer and einkorn than for modern wheat.

Emmer and einkorn need to be planted in their hulls to get adequate germination. Spelt can be planted in or out of the hull. Research trials have shown a rate of 100 pounds per acre to be suitable for spring emmer and einkorn. Research is needed to determine rates for winter emmer and einkorn, although farmer experience suggests that even lower planting rates, such as 80 pounds per acre or lower, may be used. Spelt planting rate depends on whether it is planted in or out of the hull. For example, in Pennsylvania, farmers plant spelt at about 120 pounds per acre when dehulled, and about 150 pounds per acre when in the hull.

Chapter 3: Special Planting Considerations

Planting einkorn, emmer, and spelt in their hulls has challenges. The hulled seeds can clog seeding equipment, which results in skips in the field. This is due to the hairs and awns on the hulls, along with the larger size of the seed in the hull.

There are various ways to accommodate these seed characteristics in planting. Well-executed combining can remove most of the awns from the seeds. A debearder can be used to remove the hairs and awns and break up doubles before seeding. Seeding equipment may be modified to accommodate the seed characteristics, or the seed can be broadcast.

Certain varieties, such as winter emmer, have very large seeds. These larger seeds may require broadcast seeding or double planting.

Chapter 4: Dehulling Systems

A percent of the harvest of hulled wheats will dehull in the combine or thresher, but an additional dehulling and cleaning process is required to extract maximum yield and to create an edible and marketable product.

The ease of dehulling will vary depending on the species, variety, and growing conditions. For example, spelt tends to be easier to dehull than emmer or einkorn. The spelt variety Maverick is easier to dehull than others, such as Oberkulmer. Well-dried grain and low humidity are required for highest dehulling efficiency.

There are two main types of dehullers, impact and friction. In an impact dehuller, the hulled grain is thrown at high speed against a hard surface or impact ring. As the grain hits the surface, the kernel is separated from the hull. Several commercial impact dehullers are available.

In friction dehullers, the kernel is rubbed loose from the hull using one of several mechanisms. One method is to rub the grain against a rubber surface. Farmers have made very low-cost friction dehullers by replacing one or both of the metal plates in a burr mill with a rubber disk. Another farmer-built dehuller uses sections of combine rasp bars mounted on a drum to dehull grains. Yet another method of friction dehulling is to force the hulled grain through a mesh screen.

In addition to the dehuller an air column, or aspirator, is used to blow off empty hulls. A separator is used to sort dehulled kernels from those still in the hull. A commonly used separator is a gravity table. Both a separator and an aspirator are necessary to achieve a high-quality product. Some dehullers such as the Nigel Tudor model include an aspirator. The Horn friction dehuller includes both an aspirator and a gravity table.

The ancient hulled wheats, spelt, emmer, and einkorn are potentially high-value food crops that could fit well into an organic farming system. They require careful management and an extra processing step called dehulling to ready them for market.

To learn more about growing, processing, and marketing the ancient hulled wheats, visit these sites: http://www.ogrin.org, http://www.npsas.org, and https://www.grownyc.org/grains.

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 22170

Organic Seed Production Webinar Series 2016

mar, 2017/05/16 - 18:33

A six-webinar series on organic seed production provides training for seed growers and seed production interns. This series, offered by Organic Seed Alliance (OSA) and the Multinational Exchange for Sustainable Agriculture (MESA), covers a range of topics, from planting to harvest to the economics of seed production. The series was delivered as part of a seed internship program offered by OSA and MESA with support from the USDA Beginning Farmer and Rancher Development Program. The recordings are appropriate for farmers, interns, students, and other agricultural professionals. Watch the recordings and find additional resources from these presentations below.

New: View the webinars in Spanish here!  Find out about the MESA 2017 Seed Internship here.

1. June 21st: Introduction to the Organic Seed Webinar Series.
  • Which crops should I grow?
  • Field planning
  • Recordkeeping
  • Speakers: Micaela Colley, Organic Seed Alliance; Organic Seed Grower TBD
  • Slide handout

2. July 19th: Trials and Selection

Conducting on-farm variety trials is a valuable investment of time and resources to ensure you are planting the best crop, variety and stock seed source for production of your seed crop. Field selection or roguing of a seed crop throughout the production cycle can further refine and improve the quality and performance of a variety or population. This webinar will cover the basics of conducting on-farm variety trials including sourcing germplasm, field plot design, trial evaluation, and making sense of the data. Presenters will also cover basics of field selection or roguing to improve performance of open pollinated seed crops.

Slide handout

3. August 16th: Diseases and Pests

Management of disease and pests in seed crops can be even more critical than in food production. Seed crops may encounter disease and pests unique to the plant reproductive phase and avoidance of certain seed borne diseases is critical for seed quality. Seed crops are a long season crop, often growing over twice as long and twice the size of a food crop, requiring additional management practices to reduce pests and diseases. This webinar will cover basic field practices for avoiding diseases and pests in seed production and post harvest. Presenters will also provide guidance on prevention, testing and treatment for seed borne diseases in organic seed production.

Slide handout

4. September 20th: Seed Quality, Harvesting Techniques and Equipment

Deciding when and how to harvest seed can be one of the most tenuous steps that will ultimately impact the yield and quality of your seed crop. This webinar will cover basic principles for determining the optimum timing of harvest and guidance on how to harvest either by hand or with equipment. Presenters will also cover tips and tools for preliminary threshing and drying post harvest and addressing inclement weather during the harvest process.

Slide handout

5. October 18th: Cleaning and Recordkeeping

Cleaning seed can be either gratifying or frustrating depending on your knowledge, equipment, and space for handling seed. This workshop will cover the basics of cleaning wet and dry seed by hand or with small to large-scale equipment. Farmer participants will share their seed cleaning tricks, tools and facilities and engage in trouble shooting questions with participants. Tips and resources for record keeping will help ensure seed lots are in order at the end of the season and you can recall cleaning methods in future years. Speakers: Rowen White, Sierra Seed Coop; Laurie McKenzie, Organic Seed Alliance; Jared Zystro, Organic Seed Alliance.

Slide handout

6. November 15th: Seed Contracting, Economics and Policy

Good business relations and management skills are critical to the success of all seed operations whether selling direct market or wholesale. Seed for wholesale is normally grown under contract with a retail seed company that will then pack and sell seeds to farmers and gardeners. Success in wholesale contracts requires assessing the costs of production and rate of return as well as building a good relationship with the contracting seed company. Join this webinar to hear from seed company representatives and a seed grower about when and how to plan for contract production and how to assess profitability. Presenters will also share perspectives on the details to consider in a contract including terms for pricing, over-production, field roguing, and seed cleaning.

: Melanie Hernandez, High Mowing Organic Seeds; Ira Wallace, Southern Exposure Seed Exchange; Daniel Brisebois, Tourne-Sol Seed Cooperative; Micaela Colley and Steve Peters, Organic Seed Alliance

A series of recorded webinars on the economics of seed production from the 2016 Organic Seed Growers Conference are available on eOrganic. These webinars present advice and tools on assessing the economics of seed production from 3 different seed producing operations. We recommend watching these videos in advance of the Seed Contracting and Economics webinar to provide background on assessing pricing in wholesale contracts.

Additional Resources from the Organic Seed Alliance

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 18970

Organic Seed Production Six Webinar Series 2017

ven, 2017/05/12 - 13:29

For the second year in a row, the Organic Seed Alliance (OSA) and the Multinational Exchange for Sustainable Agriculture (MESA) are presenting a series of six webinars on organic seed production. The webinars cover everything from planting to harvest, to the economics of seed production. The series is part of an organic seed internship program organized by OSA and MESA, but the free webinars are open to everyone. Advance registration is required--registering just once will allow you to attend all the webinars. The series will cover the same topics as the 2016 series, but whether or not you attended last year, you are welcome to join and type in questions for the presenters. Starting on May 16th, there will be one webinar on the third Tuesday of each month through October at 2PM Eastern, 1PM Central, 12PM Mountain and 11AM Pacific Time.

Register for the 2017 Organic Seed Production Webinar Series at:
https://attendee.gotowebinar.com/register/2788257417038326785

If you would prefer to watch the recordings from the 2016 series, they are available along with additional resources in at the following links:

Find out more about the organic seed internship program at https://learn.mesaprogram.org/courses/organic-seed-internship/

Schedule Tue, May 16, 2017: Introduction and Crop Planning
  • Which crops should I grow?
  • Field planning
  • Recordkeeping
Tue, Jun 20, 2017: Trials and Selection

Conducting on-farm variety trials is a valuable investment of time and resources to ensure you are planting the best crop, variety and stock seed source for production of your seed crop. Field selection or roguing of a seed crop throughout the production cycle can further refine and improve the quality and performance of a variety or population. This webinar will cover the basics of conducting on-farm variety trials including sourcing germplasm, field plot design, trial evaluation, and making sense of the data. Presenters will also cover basics of field selection or roguing to improve performance of open pollinated seed crops.

Tue, Jul 18, 2017: Diseases and Pests

Management of disease and pests in seed crops can be even more critical than in food production. Seed crops may encounter disease and pests unique to the plant reproductive phase and avoidance of certain seed borne diseases is critical for seed quality. Seed crops are a long season crop, often growing over twice as long and twice the size of a food crop, requiring additional management practices to reduce pests and diseases. This webinar will cover basic field practices for avoiding diseases and pests in seed production and post harvest. Presenters will also provide guidance on prevention, testing and treatment for seed borne diseases in organic seed production.

Tue, Aug 15, 2017: Seed Quality, Harvesting and Equipment

Deciding when and how to harvest seed can be one of the most tenuous steps that will ultimately impact the yield and quality of your seed crop. This webinar will cover basic principles for determining the optimum timing of harvest and guidance on how to harvest either by hand or with equipment. Presenters will also cover tips and tools for preliminary threshing and drying post harvest and addressing inclement weather during the harvest process.

Tue, Sep 19, 2017: Seed Cleaning and Recordkeeping

Cleaning seed can be either gratifying or frustrating depending on your knowledge, equipment, and space for handling seed. This workshop will cover the basics of cleaning wet and dry seed by hand or with small to large-scale equipment. Farmer participants will share their seed cleaning tricks, tools and facilities and engage in trouble shooting questions with participants. Tips and resources for record keeping will help ensure seed lots are in order at the end of the season and you can recall cleaning methods in future years.

Tue, Oct 17, 2017: Seed Contracting, Economics and Policy

Good business relations and management skills are critical to the success of all seed operations whether selling direct market or wholesale. Seed for wholesale is normally grown under contract with a retail seed company that will then pack and sell seeds to farmers and gardeners. Success in wholesale contracts requires assessing the costs of production and rate of return as well as building a good relationship with the contracting seed company. Join this webinar to hear from seed company representatives and a seed grower about when and how to plan for contract production and how to assess profitability. Presenters will also share perspectives on the details to consider in a contract including terms for pricing, over-production, field roguing, and seed cleaning.

Additional Resources

 

Funding for this program is provided by the USDA Beginning Farmer and Rancher Development Program.

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 22665

Producción Orgánica de Semillas

lun, 2017/04/24 - 14:13

Este seminario en línea es presentado por la Alianza por las Semillas Orgánicas (OSA) y el Programa para el Intercambio Multinacional por la Agricultura Sostenible (MESA).

Find the English version here.

Parte 1: Por dónde empezar

Presentación traducida al castellano del seminario en línea liderado por la Alianza por las Semillas Orgánicas, sobre la planificación para producir semillas orgánicas. Toca temas de la biología básica de las semillas y elementos técnicos para producir semilla orgánica exitosamente.

Parte 2: Ensayos y Selección

Presentación sobre ensayos y selección. Explica el porque es importante hacer ensayos con semillas, cómo hacerlos y qué tipo de información nos brinda.

Parte 3: Manejo de Plagas y Enfermedades en la producción de Semillas

Esta es la parte 3 de una serie de 6 seminarios en linea sobre producción orgánica de semillas. En el se discuten elementos sobre la prevención y manejo de plagas y enfermedades en la producción de semillas.

 

Parte 4: Calidad de las Semillas, Cosecha y Equipos en la Producción de Semillas Orgánicas

Esta es la parte 4 de una serie de 6 seminarios en línea sobre producción orgánica de semillas. En el se discuten elementos sobre el control de calidad, la cosecha y los equipos utilizados en la producción de semillas.

Parte 5: Limpieza de Semillas

Esta es la parte 5 de una serie de 6 seminarios en línea sobre producción orgánica de semillas. En el se discuten elementos sobre la limpieza y purificación de las semillas.

Parte 6: Aspectos Económicos de la Producción de Semillas y Contratación

Esta es la parte 6 de una serie de 6 seminarios en línea sobre producción orgánica de semillas. En el se discuten los aspectos económicos de la producción de semillas y elementos relacionados con la contratación en esta actividad.

 Recursos adicionales

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 22521

Identification, Diet, and Management of Chickadees and Warblers Common on Organic Farms

lun, 2017/04/24 - 13:33

eOrganic authors:

Olivia M. Smith, School of Biological Sciences, Washington State University

William E. Snyder Ph.D., Department of Entomology, Washington State University

Introduction

A growing body of experimental evidence suggests that birds play important roles as natural enemies in agricultural ecosystems. For example, a study conducted in Europe demonstrated the important services provided by Great Tits (Parus major) in apple orchards. Researchers experimentally added nest boxes to some plots and saw an increase in fruit yield from 4.7 to 7.8 kg per tree. Increased yield was attributed to predation of caterpillars by Great Tits (Mols et al., 2002). A review paper by Bael et al. (2008) found that across 48 studies examined, birds reduced arthropods and plant damage. Here we focus on identification, diet, and management of chickadees and warblers observed on West Coast vegetable farms and discuss their natural pest control services. This is the third article in a series about avian insectivores on farms. 

Black-capped Chickadee (Poecile atricapillus)

Figure 1. Black-capped Chickadee. Photo credit: Mick Thompson, Black-capped Chickadee, CC Attribution-NonCommercial 2.0

Identification

As its common name implies, this chickadee has a black cap. It also has a black chin, white cheeks, a white breast and belly, buffy flanks, and grayish wings and tail. Chickadees have small bills. The entire length of the Black-capped Chickadee averages about 12.3–14.6 cm, and they weigh on average only 10–14 g (Fig. 1; Foote et al., 2010). The Black-capped Chickadee has complex vocal behaviors with 16 unique types of vocalizations (Smith, 1991). The whistled song is typically two clear tones with a higher-pitched fee note followed by a lower-pitched bee note. The Black-capped Chickadee also has a chick-a-dee call that is the namesake of the genus. Mountain Chickadees are similar in appearance but have an obvious white eyebrow called a supercilium, and are primarily found in higher altitude montane coniferous forests (Fig. 2; McCallum et al., 1999). 

Figure 2. Mountain Chickadee. Note the prominent white eyebrow called the supercilium. Photo credit: Julio Mulero, Mountain Chickadee, CC Attribution-NonCommercial-NoDerivs 2.0

Diet

During the breeding season, the Black-capped Chickadee's diet is about 80–90% animal matter (primarily caterpillars), with the rest of the diet comprised of fruit and seeds. During the winter, the diet shifts to about 50% animal matter (primarily insects and spiders) and 50% plant matter (primarily seeds and berries) (Smith, 1991). The Black-capped Chickadee primarily forages on trees by gleaning insects off the bark and leaves, and rarely forages on the ground. Approximately 58% of arthropod prey are taken from bark and 38.2% are taken from leaves (n = 451, Robinson and Holmes, 1982). One study found that chickadees can use leaf damage cues to locate cryptic caterpillars (Heinrich and Collins, 1983). Chickadees are rarely found in vegetable fields, but are commonly found foraging in orchards. Caterpillars comprise the largest portion of the chickadee diet, with other insects, spiders, small snails, small slugs, and centipedes forming smaller components (Bent, 1946; Robinson and Holmes, 1982; Smith, 1991). The Black-capped Chickadee is known to take blueberries and blackberries as available (Foote et al., 2010).

Management

Results from the North American Breeding Bird Survey indicate a 0.59% range-wide increase from 1966-2012, but this species is declining in the Pacific Northwest (Sauer et al., 2014). The Black-capped Chickadee can be found in a wide variety of habitats as long as trees are present. Clearing trees for agriculture can create more forest edge, which is a preferred habitat for chickadees (Foote et al., 2010). Black-capped Chickadees are year-round residents, and providing supplemental food at feeders in the winter can improve survival rates (Brittingham and Temple, 1988). This species is able to excavate its own nest cavities in tree species such as birch and aspen, but can also use cavities excavated by other species (Mennill and Ratcliffe, 2004; Foote et al., 2010). Nest trees average 20.5 cm diameter at breast height (DBH) (Ramsay et al., 1999). Chickadees will nest in artificial nests when natural cavities are rare. Black-capped Chickadees are more likely to use artificial snags than nest boxes. Usage of both increase when cavities are filled with wood shavings (Cooper and Bonter, 2008). Invasive House Sparrows (Passer domesticus) can outcompete chickadees for nest cavities and boxes, so constructing boxes with entrance holes small enough to exclude House Sparrows is important (about 2.86–3.18 cm diameter). Instructions on nest construction and placement can be found here. Additionally, many businesses sell pre-made nest boxes. Instructions on deterrence and removal of House Sparrows can be found here.

Chestnut-backed Chickadee (Poecile rufescens)

Figure 3. Chestnut-backed Chickadee. Photo credit: Jerry McFarland, Chestnut-backed Chickadee, CC Attribution-NonCommercial 2.0

Identification

As its common name implies, the Chestnut-backed Chickadee has a chestnut back and flanks and a brown cap (Fig. 3). The entire length of the male Chestnut-backed Chickadee averages about 10.5–12.5 cm, while the average length of the female is about 10.0–11.4 cm. The average weight is only 8.5–12.6 g (Dahlsten et al. 2002), making it slightly smaller on average than the Black-capped Chickadee. It also lacks the whistled song present in the Black-capped Chickadee, but has a well-defined chick-a-dee call. The Chestnut-backed Chickadee's chick-a-dee call is higher, faster, shorter, and huskier than the Black-capped Chickadee's. The Chestnut-backed Chickadee is notable for its preference for coniferous forest habitat (Smith, 1991). The Chestnut-backed Chickadee tends to forage higher in trees and more often in conifers than the Black-capped Chickadee (Sturnman, 1968). 

Diet

Arthropods comprise approximately 65% of the annual diet, with leafhoppers, treehoppers, scales, spiders, wasps, and caterpillar larvae among preferred food items. Seeds and plant material (fruit pulp and other miscellaneous matter) make up the remaining 35% of the diet (Beal, 1907; Dixon, 1954). Nestlings are fed caterpillars, sawfly larvae, crickets, spiders, and flies (Kleintjes and Dahlsten, 1994). Chestnut-backed Chickadees are canopy foragers, primarily foraging on leaf surfaces—unlike bark-gleaning Black-capped Chickadees—and are often found in oak, fir, or pine (Dixon, 1954; Root, 1964; Sturnman, 1968; Brennan et al., 2000). Chestnut-backed Chickadees are frequently observed foraging in fence rows with conifers and forests adjacent to farms but rarely, if ever, forage among farmed areas. Chestnut-backed Chickadees may be extremely beneficial to the forestry industry through natural pest control services (Kleintjes and Dahlsten, 1994).

Management

Results from the North American Breeding Bird Survey indicate a 1.77% range-wide decline from 1966–2012, with a similar trend of decline (1.66%) in the Pacific Northwest (Sauer et al., 2014). Nesting requirements are similar to the Black-capped Chickadee (see above). Leaving snags and adding nest boxes can encourage nesting (Dahlsten et al., 2002). Visit nestwatch for detailed nest building and placement information.

Common Yellowthroat (Geothlypis tichas)

Figure 4. Male Common Yellowthroat. Photo credit: Dan Pancamo, Common Yellowthroat, CC Attribution-ShareAlike 2.0

Figure 5. Female Common Yellowthroat. Photo Credit: John Benson, Common Yellowthroat, CC Attribution 2.0

Identification

Male and female Common Yellowthroat are sexually dimorphic, meaning they do not look the same. The male has a black mask, a yellow throat, and an olive green back, nape, wings, and tail (Fig. 4). Males have a distinct wich-i-ty wich-i-ty wich-ity song which is variable by region, but always contains the wich component. The female is mostly dull olive-gray with a dull yellow throat (Fig. 5). The female could be easily confused with other small warblers such as the Orange-crowned Warbler or Nashville Warbler. The female is also similar to female American and Lesser Goldfinches, but warbler bills are less stocky and the Common Yellowthroat lacks the distinct wing bars present in the goldfinches. The entire length of the Common Yellowthroat averages about 11–13 cm, and they weigh on average only 9–10 g (Guzy and Ritchinson, 1999).

Diet

The Common Yellowthroat forages on the ground and in low vegetation for insects, making it a frequent and welcome visitor to crop fields and orchards. Adult Common Yellowthroat consume spiders, caterpillars, true bugs, flies, beetles, ants, and other various larvae (Rosenberg, 1982), but a detailed diet analysis study is lacking. Food brought to nestlings include moths, spiders, mayflies, caterpillars, damselflies, and beetles (Shaver, 1918).

Management

Results from the North American Breeding Bird Survey indicate a 0.96% range-wide decline from 1966–2012, but populations in the western portion of the range have shown increases during the same period (Sauer et al., 2014). Common Yellowthroats build open-cup nests on or near the ground, often supported by herbaceous plants, but sometimes by shrubs. Nests are often placed near wetlands, are built primarily of plant material, and average about 8.5 cm in diameter (Stewart, 1953). Common Yellowthroats are present in a variety of habitats, but promoting dense vegetation is recommended for attracting Common Yellowthroat (Guzy et al., 1999). Growers often promote vegetation around drainage ditches, add hedgerows, and restore wetlands—all of which attract Common Yellowthroats. A great resource for habitat recommendations is yardmap.org.

More Resources

The Cornell Lab of Ornithology (birds.cornell.edu) supports a great citizen scientist network with detailed information on nest construction and placement (nestwatch.org), recommendations on attracting species of interest (content.yardmap.org), and range information (ebird.org). The lab offers many opportunities for the public to get involved with scientific data collection through Project Feederwatch (feederwatch.org), eBird (eBird.org), and Nestwatch (nestwatch.org). Basic species information can be found at allaboutbirds.org, and the Merlin Bird ID app can aid in field identification.

This is the third article in a series about insectivorous birds on organic farms.

Swallows and Swifts

Western Bluebird

References
  • Bael, S.A.V., S. M. Philpott, R. Greenberg, P. Bichier, N. A. Barber, K. A. Mooney, and D. S. Gruner. 2008. Birds as predators in tropical agroforestry systems. Ecology 89:928–934. Available online at: http://onlinelibrary.wiley.com/doi/10.1890/06-1976.1/full (verified 13 April 2017).
  • Beal, E.E.L. 1907. Birds of California in relation to the fruit industry, Part I. Bulletin of the United States National Museum 30.
  • Bent, A. C. 1946. Life histories of North American jays, crows, and titmice, Part I. Bulletin of the United States National Museum 191.
  • Brennan, L. A., M. L. Morrison, and D. L. Dahlsten. 2000. Comparative foraging dynamics of Chestnut-backed and Mountain Chickadees in the Western Sierra Nevada. Northwestern Naturalist 81:129–147. Available online at: http://www.jstor.org/stable/3536824 (verified 6 January 2017).
  • Brittingham, M. C., and S. A. Temple. 1988. Impacts of supplemental feeding on survival rates of Black-capped Chickadees. Ecology 69:581–589. Available online at: http://www.jstor.org/stable/1941007 (verified 5 January 2017).
  • Cooper, C., and D. Bonter. Artificial nest site preferences of Black-capped Chickadees. Journal of Field Ornithology 79:193–197. Available online at: http://www.jstor.org/stable/27715259 (verified 5 January 2017).
  • Dahlsten, D. L., L. A. Brennan, D. A. McCallum, and S. L. Gaunt. 2002. Chestnut-backed Chickadee (Poecile rufescens). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: https://birdsna.org/Species-Account/bna/species/cbchi (verified 6 January 2017).
  • Dixon, K. L. 1954. Some ecological relations of chickadees and titmice in Central California. The Condor 56: 113–124. Available online at: http://www.jstor.org/stable/1364777 (verified 6 January 2017).
  • Foote, J. R., D. J. Mennill, L. M. Ratcliffe, and S. M. Smith. 2010. Black-capped Chickadee (Poecile atricapillus). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: https://birdsna.org/Species-Account/bna/species/bkcchi (verified 5 January 2017).
  • Guzy, M. J., and G. Ritchinson. 1999. Common Yellowthroats (Geothlypis trichas). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: https://birdsna.org/Species-Account/bna/species/comyel (verified 7 January 2017).
  • Heinrich, B., and S. L. Collins. 1983. Caterpillar leaf damage, and the game of hide-and-seek with birds. Ecology 64:592–602. Available online at: http://www.jstor.org/stable/1939978 (verified 5 January 2017).
  • Kleintjes, P. K., and D. L. Dahlsten. 1994. Foraging behavior and nestling diet of Chestnut-backed Chickadees in Monterey Pine. The Condor 96:647–653. Available online at: http://www.jstor.org/stable/1369468 (verified 6 January 2017).
  • McCallum, D. A., R. Grundel, and D. L. Dahlsten. 1999. Mountain Chickadee (Poecile gambeli). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: https://birdsna.org/Species-Account/bna/species/mouchi (verified 5 January 2017).
  • Mennill, D. J., and L. M. Ratcliffe. 2004. Nest cavity orientation in Black-capped Chickadees Poecile atricapillus: Do the acoustic properties of cavities influence sound reception in the nest and extra-pair matings? Journal of Avian Biology 35:477–482. Available online at: http://www.jstor.org/stable/3677551 (verified 5 January 2017).
  • Mols, C. M., and M. E. Visser. 2002. Great Tits can reduce caterpillar damage in apple orchards. Journal of Applied Ecology 39:888–899. Available online at: http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2664.2002.00761.x/full (verified 13 April 2017).
  • Ramsey, S. M., K. Otter, and L. M. Ratcliffe. 1999. Nest-site selection by female Black-capped Chicakdees: Settlement based on conspecific attraction? The Auk 3:604–617. Available online at: http://www.jstor.org/stable/4089322 (verified 5 January 2017).
  • Robinson, S. K., and R. T. Holmes. 1982. Foraging behavior of forest birds: The relationships among search tactics, diet, and habitat structure. Ecology 63:1918–1931. Available online at: http://www.jstor.org/stable/1940130 (verified 5 January 2017).
  • Root, R. B. 1964. Ecological interactions of the Chestnut-backed Chickadee following a range extension. The Condor 66:229–238. Available online at: http://www.jstor.org/stable/1365648 (verified 6 January 2017).
  • Rosenberg, K. V., R. D. Ohmart, and B. W. Anderson. 1982. Community organization of riparian breeding birds: Response to an annual resource peak. The Auk 2:260–274. Available online at: http://www.jstor.org/stable/4085973 (verified 6 January 2017).
  • Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2014. The North American Breeding Bird Survey, results and analysis 1966–2013. Version 01.30.2015 USGS Patuxent Wildlife Research Center, Laurel, MD. Available online at: https://www.mbr-pwrc.usgs.gov/bbs/ (verified 6 January 2017).
  • Shaver, N. E. 1918. A nest study of the Maryland Yellow-throat. University of Iowa Studies of Natural History 8:1–12.
  • Smith, S. M. 1991. The Black-capped Chickadee: Behavioral ecology and natural history. Cornell University Press, Ithaca, NY.
  • Stewart, R. E. 1953. A life history study of the yellow-throat. The Wilson Bulletin 65:99–115.
  • Sturman, W. A. 1968. The foraging ecology of Parus atricapillus and P. rufescens in the breeding season, with comparisons with other species of Parus. The Condor 70:309–322. Available online at: http://www.jstor.org/stable/1365925 (verified 6 January 2017).

     

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 21871

Western Bluebird (Sialia mexicana) Identification, Diet, and Management for Organic Farmers

lun, 2017/04/24 - 13:16

eOrganic authors:

Olivia M. Smith, School of Biological Sciences, Washington State University

William E. Snyder Ph.D., Department of Entomology, Washington State University

Introduction

A growing body of experimental evidence suggests that birds play important roles as natural enemies in agricultural ecosystems. For example, a study conducted in Europe demonstrated the important services provided by Great Tits (Parus major) in apple orchards. Researchers experimentally added nest boxes to some plots and saw an increase in fruit yield from 4.7 to 7.8 kg per tree. Increased yield was attributed to predation of caterpillars by Great Tits (Mols et al., 2002). A review paper by Bael et al. (2008) found that across 48 studies examined, birds reduced arthropods and plant damage. Here we focus on identification, diet, and management of Western Bluebirds and their role in farming. In addition to the insects this species consumes, we make suggestions for how to manage bluebirds to maximize their benefits while minimizing their risks. This is the second article in a series about avian insectivores on farms. 

Identification

Figure 1. Western Bluebird male holding an insect. Photo credit: Nigel Winnu, Western Bluebird, CC Attribution 2.0

Figure 2. Western Bluebird female. Photo credit: Martin Jambon, Female Western Bluebird, CC Attribution 2.0 Generic

Western Bluebirds (Sialia mexicana) are in the thrush family along with the familiar American Robin (Turdus migratorius) and the possibly less familiar Swainson's Thrush (Catharus ustulatus). Western Bluebird males are strikingly blue on the head, neck, wings, and tail. A rust-orange belt crosses the breast, with a slightly duller blue on the belly than the wings (Fig. 1). The brilliant blue on males is replaced by a duller blue-gray on females and juveniles (Fig. 2). The similar Mountain Bluebird (Sialia currucoides) lacks the rusty breast and flank plumage of the Western Bluebird, and the Mountain Bluebird is more sky blue (Fig. 3). The Eastern Bluebird (Sialia sialis) is also similar in appearance to the Western Bluebird, but its rust color extends up the throat, and it lacks blue on the breast (Fig. 4). The Eastern Bluebird occurs further east than the Western Bluebird; however, the Western Bluebird has been expanding eastward over the last several decades and displacing Eastern Bluebirds due to greater aggression and high dispersal ability (see Fig. 5 for a range map; Duckworth and Badyaev, 2007). Another similar species is the Lazuli Bunting (Passerina amoena), but the Lazuli Bunting has prominent wing bars, a smaller body size, and a thicker bill (Fig. 6).

Figure 3. Mountain Bluebird. Photo credit: Nigel Winnu, Nigel Winnu, Mountain Bluebird, CC Attribution 2.0

Figure 4. Eastern Bluebird. Photo credit: Jeff Bryant, Eastern Bluebird, CC Attribution 2.0

 

Fig 5. Range map for the Western Bluebird from eBird. [Image provided by eBird (www.ebird.org) and created 10 January 2017]

Fig 6. Lazuli Bunting. Photo credit: Julio Mulero, Lazuli Bunting, CC Attribution-NonCommercial-NoDerivs 2.0

Diet

Western Bluebirds are primarily insectivorous ground gleaners (De Graaf et al., 1985) and often forage off of perches. Grasshoppers and beetles may be the most important portion of the nestling bluebird diet (Beal, 1915; Herlugson, 1982). A study conducted in South-central Washington examined the diet of bluebird adults and chicks in the breeding season. The nestling diet was composed of 37.5% Coleoptera (beetles), 29.2% Hymenoptera (wasps, bees), 17.5% Hemiptera (true bugs including aphids and scales), 9.4% Orthoptera (grasshoppers), 2.5% Lepidoptera (caterpillars), and 1.0% Arachnida (spiders). Actual biomass of each taxa in the nestling diet differed slightly than the number of individuals consumed: 58.27% Orthoptera, 22.85% Homoptera, 10.42% Coleoptera, 4.45% Arachnida, 3.80% Lepidoptera, and 0.21% Hymenoptera. The adult diet differed slightly from the nestling diet. The primary constituents of the adult diet were beetles (68.2%) and caterpillars (12.2%). After nestlings hatched, the diet shifted to Coleoptera (37.5%), Hymenoptera (29.2%), and Hemiptera (15.6%) (Herlugson, 1982). Beal (1915) additionally found flies and snails in gut contents. A study using a novel technique called molecular scatology tested the DNA in Western Bluebird feces and found that Aedes mosquitos comprised the highest portion of the diet (present in 49.5% of samples). Ectoparasitic bird blowfly (Protocalliphora sp.) DNA was in 7% of adult and 11% of nestling samples. Herbivorous insects from the Hemiptera and Lepidoptera orders comprised 56% of the prey items in bluebird diets. Predatory insects and parasitoid insects were less than 3% of the diet, suggesting that Western Bluebirds offer substantial ecosystem services and little risk of consuming beneficial predatory arthropods (Jedlicka et al., 2017).

Western Bluebirds have been shown to provide ecosystem services in California organic vineyards. The study experimentally added nest boxes to some vineyard sites and compared avian species richness, Western Bluebird abundance, and beet armyworm (Spodoptera exigua) predation in sites with added nest boxes and without nest boxes. The study found that with addition of nest boxes, the average species richness of avian insectivores increased by over 50%. Further, density of insectivorous birds quadrupled, and Western Bluebird abundance increased tenfold. Omnivorous and granivorous bird species (potential pest species) abundance remained constant, suggesting low risk of addition of nest boxes. Plots with nest box addition had 2.4 times more live beet armyworm removal. Further, immediately below nest boxes, removal was 3.5 times higher than in the control (Jedlicka et al., 2011). This study suggests addition of nest boxes for insectivorous birds may be an important part of Integrated Pest Management.

Habitat during the Growing Season

Habitat usage varies throughout the range, but typical habitats are open coniferous and deciduous forests, forest edges, farms, and orchards. In the Willamette Valley, Western Bluebirds are common in open country with scattered trees and orchards, whereas in the eastern Cascades, they are more common in Douglas fir (Pseudotsuga menziesii) and open pine forests (Gilligan et al., 1994). In southern California, Western Bluebirds are primarily found in open oak woodlands and coniferous forests, and rarely in areas with large row crop fields (Garrett and Dunn, 1981).

Management

Results from the North American Breeding Bird Survey indicate a 0.58% range-wide increase from 1966-2012 (Sauer et al., 2014); however, in the Northern Pacific Rainforest, there was a -1.25% decline from 1966-2012 (Sauer et al., 2014). Western Bluebirds are a State Monitor Species in Washington State (Washington Department of Fish and Wildlife; 2017) and are listed as Vulnerable in Oregon (Oregon Department of Fish and Wildlife, 2008). The most important likely contributors are loss of suitable nest sites and foraging areas due to logging, fire suppression, grazing, and urbanization (Herlugson, 1975; Brawn and Balda, 1988). The Western Bluebird is a secondary cavity nester, meaning it requires cavities excavated by other species, and relies on availability of snags, large living trees, or nest boxes (Guinan et al., 2008). Proposed measures include controlled and natural burning, prohibition of snag removal, and preservation of old, partially dead trees (Herlugson, 1975). An estimated 57% of the Washington Western Bluebird population lives on private land (Cassidy and Grue, 2000), suggesting the importance of private landowners providing suitable habitat for this species. Western Bluebirds compete with other native species like the Violet-green Swallow (Tachycineta thalassina) for nest sites, along with invasive House Sparrows (Passer domesticus) and European Starlings (Sturnus vulgaris) (Gillis, 1989). Instructions on deterrence and removal of invasive species can be found here. Bluebird nest-box trails have been implemented to add and monitor nest boxes (Fig. 7). Success is limited by competition with other bird species, but the numbers of nest boxes used by bluebirds has increased markedly since the program began (Guinan et al., 2008). Instructions on nest construction and placement can be found here.

Figure 7. Western Bluebird emerging from a Bluebird Trail nest box. Photo credit: Mick Thompson, Western Bluebird, CC Attribution-NonCommercial 2.0

More Resources

The Cornell Lab of Ornithology (birds.cornell.edu) supports a great citizen scientist network with detailed information on nest construction and placement (nestwatch.org), recommendations on attracting species of interest (content.yardmap.org), and range information (ebird.org). The lab offers many opportunities for the public to get involved with scientific data collection through Project Feederwatch (feederwatch.org), eBird (eBird.org), and Nestwatch (nestwatch.org). Basic species information can be found at allaboutbirds.org, and the Merlin Bird ID app can aid in field identification.

This is the second article in a series about insectivorous birds on organic farms. 

Swallows and Swifts

Chickadees and Warblers

References and Citations
  • Bael, S.A.V., S. M. Philpott, R. Greenberg, P. Bichier, N. A. Barber, K. A. Mooney, and D. S. Gruner. 2008. Birds as predators in tropical agroforestry systems. Ecology 89:928—934. Available online at: http://dx.doi.org/10.1890/06-1976.1 (verified 18 April 2017).
  • Beal, F.E.L. 1915. Food of the robins and bluebirds of the United States. Bulletin of the United States Department of Agriculture 171.
  • Brawn, J. D., and R. P. Balda. 1988. Population biology of cavity nesters in Northern Arizona: Do nest sites limit breeding densities? The Condor 90:61—71. Available online at: http://www.jstor.org/stable/1368434 (verified 10 January 2017).
  • Cassidy, K. M., and C. E. Grue. 2000. The role of private and public lands in conservation of at-risk vertebrates in Washington State. Wildlife Society Bulletin 28:1060—1076. Available online at: http://www.jstor.org/stable/3783867 (verified 10 January 2017).
  • De Graaf, R. M., N. G. Tilghman, and S. H. Anderson. 1985. Foraging guilds of North American birds. Environmental Management 9:493—536. Available online at: http://dx.doi.org/10.1007/BF01867324 (verified 10 January 2017).
  • Duckwork, R. A., and A. V. Badyaev. 2007. Coupling of dispersal and aggression facilitates the rapid expansion of a passerine bird. Proceedings of the National Academy of Sciences of the United States of America 104:15017—15022. Available online at: http://www.pnas.org/content/104/38/15017 (verified 10 January 2017).
  • Garrett, K., and J. Dunn. 1981. Birds of southern California: Status and distribution. Los Angeles Audubon Society, Los Angeles, CA.
  • Gilligan, J., D. Rogers, M. Smith, and A. Contreras. 1994. Birds of Oregon: Status and distribution. Cinclus Publications, McMinnville, OR.
  • Gillis, E. 1989. Western Bluebirds, Tree Swallows, and Violet-green Swallows west of the Cascade Mountains in Oregon, Washington, and Vancouver Island, British Columbia. Sialia 11:127—130.
  • Guinan, J. A., P. A. Gowaty, and E. K. Eltzroth. 2008. Western Bluebird (Sialia Mexicana). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: https://birdsna.org/Species-Account/bna/species/wesblu (verified 10 January 2017).
  • Herlugson, C. J. 1975. Status and distribution of the Western Bluebird and the Mountain Bluebird in the state of Washington. Master's Thesis, Washington State University, Pullman, WA.
  • Herlugson, C. J. 1982. Food of adult and nestling Western and Mountain Bluebirds. The Murrelet 63:59—65. Available online at: http://www.jstor.org/stable/3533829 (verified 10 January 2017).
  • Jedlicka, J. A., R. Greenberg, and D. K. Letourneau. 2011. Avian conservation practices strengthen ecosystem services in California vineyards. PLoS ONE 6: e27347. Available online at: http://dx.doi.org/10.1371/journal.pone.0027347 (verified 10 January 2017).
  • Jedlicka, J. A., A. E. Vo, and R.P.P. Almeida. 2017. Molecular scatology and high-throughput sequencing reveal predominately herbivorous insects in the diets of adult and nestling Western Bluebirds (Sialia mexicana) in California vineyards. The Auk 134:116—127. Available online at: http://dx.doi.org/10.1642/AUK-16-103.1 (verified 16 January 2017).
  • Mols, C. M., and M. E. Visser. 2002. Great Tits can reduce caterpillar damage in apple orchards. Journal of Applied Ecology 39:888—899. Available online at: http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2664.2002.00761.x/full (verified 13 April 2017).
  • Oregon Department of Fish and Wildlife [Online]. Wildlife Division/Conservation/Species/Sensitive species. Available at: http://www.dfw.state.or.us/wildlife/diversity/species/sensitive_species.asp (verified 19 April 2017).
  • Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2014. The North American breeding bird survey, results and analysis 1966—2013. Version 01.30.2015 USGS Patuxent Wildlife Research Center, Laurel, MD. Available online at: https://www.mbr-pwrc.usgs.gov/bbs/ (verified 2 January 2017).
  • Washington Department of Fish & Wildlife [Online]. Washington State species of concern lists. Available at: http://wdfw.wa.gov/conservation/endangered/status/SM/ (verified 10 January 2017).

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 21870

Identification, Diet, and Management of Swallows and Swifts Common on Organic Farms

lun, 2017/04/24 - 13:15

eOrganic authors:

Olivia M. Smith, School of Biological Sciences, Washington State University

William E. Snyder Ph.D., Department of Entomology, Washington State University

Introduction

A growing body of experimental evidence suggests that birds play important roles as natural enemies in agricultural ecosystems. For example, a study conducted in Europe demonstrated the important services provided by Great Tits (Parus major) in apple orchards. Researchers experimentally added nest boxes to some plots and saw an increase in fruit yield from 4.7 to 7.8 kg per tree. Increased yield was attributed to predation of caterpillars by Great Tits (Mols et al., 2002). A review paper by Bael et al. (2008) found that across 48 studies examined, birds reduced arthropods and plant damage. Here we focus on identification, diet, and management of swallows and swifts observed on West Coast organic vegetable farms and discuss their natural pest control services. This is the first article in a series about avian insectivores on farms.  

Barn Swallow (Hirundo rustica)

Figure 1. Adult Barn Swallow in flight. Note the long tail streamers which set it apart from other adult swallows. Photo credit: Denise Coyle, Barn Swallow.

Identification

Barn Swallows (Fig. 1) are the most abundant swallow species in the world (Fig. 2; Brown and Brown, 1999) and are present on many farms globally (Kragsten et al., 2009). They are most easily distinguished from other swallows by their long, forked tails which are used for stability during their daring aerial acrobatics (Norberg, 1994). These swallows have blue backs, buffy breasts and bellies, and orange throats and foreheads.

Figure 2. Range map for the Barn Swallow. [Image provided by eBird (www.ebird.org) and created 4 March 2017]

Diet

Barn Swallows primarily eat flying insects; in fact, approximately 99.8% of their diet is animal matter. Thermals and convection currents occasionally lift ground insects to an altitude where swallows can consume them (Brown and Brown, 1995). Barn Swallows may be able to significantly reduce crop pest insect populations. For example, a study conducted in Poland (Orlowski et al., 2014) analyzed Barn Swallow nestling faecal sacs and found that 17.8% of the nestling diet was oilseed rape pests, with an additional 5.3% being other arable crop pests. Flies are a preferred food, including horse flies, crane flies, and robber flies. Stinkbugs, leafhoppers, and plant lice are also common prey. Less commonly eaten are ants, bees, parasitic wasps, predaceous ground beetles, ladybird beetles, weevils, dung beetles, and dragonflies. Caterpillars are rarely consumed due to the Barn Swallow's aerial foraging strategy (Beal, 1918). Open areas such as pastures and plowed fields are preferred for foraging. Barn Swallows can often be observed dutifully foraging for pesky insects behind tractors as fields are plowed and planted.

Management

Barn Swallows are one of the few bird species that have benefited from European settlement (Brown and Brown, 1999), but results from the North American Breeding Bird Survey indicate a 1.1% range-wide decline in North American populations from 1966-2012 (Sauer et al., 2014). Similarly, Barn Swallow populations have declined in Europe. The declines are largely attributed to increased pesticide usage, reduction of livestock grazing, reduction of on-farm ponds, and reduction of semi-natural habitats on farmlands (hedgerows, etc.). These changes have resulted in decreased invertebrate abundance and diversity, reducing food availability for adult and nestling swallows (Evans and Robinson, 2004; Kragsten et al., 2009).

As their name implies, Barn Swallows often nest in groups in rafter beams of barns in open cup mud nests (Fig. 3). Some growers will add narrow wooden ledges to walls or under eaves to provide nesting space. Nest removal at the end of the breeding season can help prevent buildup of ectoparasites (Brown and Brown, 2015). Detailed instructions on building and placing nests for native species can be found at the Cornell Lab of Ornithology's website nestwatch.org. However, care must be taken in nest placement because Barn Swallows can be pests when they nest above food processing areas and drop feces. Barn Swallows can vector verocytotoxin-producing Escherichia coli when living in close proximity to livestock operations, although previous studies suggest it is rare (< 2%; Nielsen et al., 2004). Barn Swallows may be exposed after consuming flies that have associated with livestock feces (Hancock et al., 1998). Many growers attempt to discourage nesting using metal spikes in open rafters. 

 

Figure 3. Barn Swallow open cup mud nest. Photo credit: Hans Schwarzkopf, Swallows

Cliff Swallow (Petrochelidon pyrrhonota)

Figure 4. Cliff Swallows nest building. Note the buffy forehead patch that distinguishes them from Barn Swallows. Also note the enclosed top on the finished nest on the left, a trait that distinguishes Cliff Swallow nests from open cup Barn Swallow nests. Photo credit: Ken Thomas, Cliff Swallows

Identification

Cliff Swallows are another widespread swallow species similar in appearance to Barn Swallows but lack long tail streamers (Fig. 4; Fig. 5). Cliff Swallows also have a distinct white forehead patch. Nests appear similar to the Barn Swallow but are enclosed rather than open cup (Fig. 3; Fig. 4). Nests are often placed in the eaves of barns. 

 

Figure 5. Range map for the Cliff Swallow. [Image provided by eBird (www.ebird.org) and created 4 March 2017]

Diet

The Cliff Swallow diet is almost entirely animal matter, with less than 1% comprised of vegetable matter. A study across the United States found that beetles were the most common food item of the Cliff Swallow, with 2.67% of the total diet being beneficial beetles such as the ladybird beetle. Like the Barn Swallow, ground beetles are typically not eaten due to the Cliff Swallow's aerial foraging habits. Other common prey include weevils, ants, bees, parasitic wasps, and flies (Beal, 1918). A diet analysis of nestlings found that grasshoppers were the primary food delivered to nestlings, but food came from 84 insect families. While Barn Swallows primarily catch single large-prey items at low altitudes (< 10 m), Cliff Swallows catch many small swarming insects at high altitudes (50 m) (Brown and Brown, 1996). Cliff Swallows commonly forage in open fields and pastures.

Management

Like the Barn Swallow, Cliff Swallows have largely benefited from European settlement (Brown and Brown, 1995), and results from the North American Breeding Bird Survey indicate a 0.4% range-wide increase from 1966-2012 (Sauer et al., 2014). Nest removal at the end of the breeding season can help prevent buildup of ectoparasites (Brown and Brown, 2015). Removal of nests in the fall can also prevent invasive House Sparrows from outcompeting Cliff Swallows. House Sparrows can roost in the nests throughout the winter and establish broods before Cliff Swallows return from migration. House Sparrow removal has been shown to be effective at increasing numbers of Cliff Swallows (Buss, 1942; Samuel, 1969; Krapu, 1986). Instructions on deterrence and removal of House Sparrows can be found here. Like the Barn Swallow, installing wooden ledges can help with nest stability.

Northern Rough-winged Swallow (Stelgidopteryx serripennis)

Figure 6. Northern Rough-winged Swallow. Note the buffy color on the flanks. Photo credit: Alan Schmierer, Northern Rough-winged Swallow, CC0 1.0 Universal

Identification

This swallow is a wide-ranging and fairly drab species that is often missed or confused with juveniles of other swallows (Fig. 6; Fig. 7). The plumage is brown on the head, nape, back, and tail and buffy white on the throat, breast, and belly. The most distinguishing feature from similar swallows is that the chest and sides have some brownish gray rather than being solid white. The species' common name comes from the rough edge on outer primary feathers (flight feathers) (De Jong, 1996). 

Figure 7. Range map for the Northern Rough-winged Swallow. [Image provided by eBird (www.ebird.org) and created 4 March 2017]

Diet

The Northern Rough-winged Swallow's diet is about 99% insect matter. A gut content analysis found flies comprised approximately 33% of the annual diet; beetles comprised 15% of the annual diet; true bugs such as stink bugs, tree hoppers, and leafhoppers comprised 15% of the annual diet; and ants comprised 12% of the annual diet. Caterpillars, moths, grasshoppers, dragonflies, and spiders comprised less than 5% of the annual diet each (Beal, 1918). The Northern Rough-winged Swallow forages at lower altitudes and above water more often than other swallow species (DeJong, 1996). 

Management

Results from the North American Breeding Bird Survey indicate a 0.4% range-wide decrease from 1966-2012, and declines were primarily in the northern and western parts of its range (Sauer et al., 2014). Northern Rough-winged Swallows occasionally nest in old Cliff Swallow nests but more often nest on bridges or in burrows in cliffs, ledges, and banks dug out by other species (Beal, 1918; DeJong, 1996). Like the Cliff and Barn Swallow, human development has increased usable nesting space. One study found that most Northern Rough-winged Swallow nests (54%, n = 224) were found in human created structures such as railroad cuts, landfills, and gravel pits (Campbell et al., 1997).

Violet-green Swallow (Tachycineta thalassina)

Figure 8. Violet-green Swallow. Note the white color that extends around the eye that distinguishes it from the similar Tree Swallow. Photo credit: Wolfgang Wander, Violet-green-swallow, CC BY-SA 3.0

Identification

As the name implies, Violet-green Swallows have green upper parts with violet upper-tail coverts and wings. They closely resemble the Tree Swallow, but the Violet-green Swallow has a shorter tail, white that extends around the eye, and a white patch on each side of the rump that is highly visible in flight (Fig. 8). The Violet-green Swallow is abundant in montane coniferous forests, and less widespread than the similar looking Tree Swallow (Fig. 9; Fig. 11; Brown et al., 2011).

Figure 9. Range map for the Violet-green Swallow. [Image provided by eBird (www.ebird.org) and created 4 March 2017]

Diet

The Violet-green Swallow almost exclusively eats flying insects. Common food items are leafhoppers, leaf bugs, flies, ants, wasps, bees, and beetles (Bent, 1942). True bugs and beetles are likely consumed primarily when convection currents bring them up into the Violet-green Swallow's foraging range (Brown et al., 2011).

Management

Results from the North American Breeding Bird Survey indicate a 0.4% range-wide decrease from 1966-2012 (Sauer et al., 2014). This species is a tree cavity nester, so conserving and restoring copses of trees will help provide for their nesting requirements. This species will also use nest boxes placed near fields, trees, or cliffs. Nesting locations are often a limiting resource, so providing nest boxes can be important for attracting cavity nesting insectivores. Instructions on building and placing swallow nest boxes can be found here and here. Additionally, many businesses sell pre-made boxes designed for swallows. Nest boxes should be cleaned out every year. Like with Cliff Swallows, introduced House Sparrows can outcompete Violet-green Swallows for nest space or destroy their eggs. Removal and deterrence of sparrows can aid in successful rearing of swallow chicks (Edson, 1943).

Tree Swallow (Tachycineta bicolor)

Figure 10. Tree Swallow. Note the more iridescent bluish hue and the bluish color that extends below the eye. Photo credit: Alan Schmierer, Tree Swallow, CC0 1.0 Universal

Identification

Tree Swallows are a widespread species with iridescent blue on their head, nape, back, tail coverts, and wing coverts (Fig. 10; Fig. 11). The wings fade into dark gray. The throat, breast, and belly are white. The tree swallow lacks the distinct white tail coverts of the Violet-green Swallow, and the white on the face ends below the eye. 

Figure 11. Range map for the Tree Swallow. [Image provided by eBird (www.ebird.org) and created 4 March 2017]

Diet

This species eats more vegetable matter than other swallow species. An early study conducted by Beal (1918) on swallow gut content found vegetable matter was about 20% of contents and was present in the diet throughout the breeding season. Diptera (flies) form the largest portion (about 40%) of the adult Tree Swallow diet, including crane flies, horse flies, and syrphid flies. Beetles comprised 14% of the diet. Dung beetles, weevils, ants, bees, parasitic wasps, dragonflies, and spiders comprised less than 5% of the diet. Tree Swallows also ate pests including aphids, stink bugs, tree hoppers, leafhoppers, plant lice, caterpillars, adult moths, and grasshoppers (Beal, 1918). A study investigating nestling diets found that boluses delivered to chicks were composed of 57% Diptera (flies), 15% Hymenoptera (bees and ants), 12% Hemiptera (true bugs), and 8% Coleoptera (beetles) (Johnson and Lombardo, 2000). Tree Swallows usually forage in open areas where flying insects are abundant and rarely glean insects off leaves (Winkler et al., 2011).

Management

Results from the North American Breeding Bird Survey indicate a 1.2% range-wide decline from 1966-2012 (Sauer et al., 2014). Availability of nests is thought to be a contributing factor (Winkler et al., 2011). Tree Swallows unsurprisingly nest in tree cavities. Like the Violet-green Swallow, they are secondary cavity nesters, meaning they rely on species such as woodpeckers to make the nests they use (Winkler et al., 2011). Tree Swallows will also nest in human-made nests and often nest in bluebird boxes (Fig. 12; Beal, 1918). Visit here or here for detailed instructions on placement and construction. Nests should be cleaned annually. 

Figure 12. Adult Tree Swallow peering out of nest. Photo credit: Ken Thomas, Tree Swallow

Vaux's Swift (Chaetura vauxi)

Figure 13. Vaux's Swift. Note the short tail and thin wings. Photo credit: Richard Crossley, Vaux's Swift from The Crossley ID Guide Eastern Birds, CC BY-SA 3.0

Identification

Though the Vaux's Swift is often confused for a swallow, it is taxonomically quite distinct. Swifts are in the order Caprimulgiformes with the nightjars, whereas swallows are in the order Passeriformes with the perching birds. The swifts were formerly placed in the same order as the hummingbirds, Apodiformes, which means “without feet,” based on similar morphology. As the taxonomic name implies, swifts have short legs with tiny feet, distinguishing them from the swallows. Swifts also have fast flapping speeds and more closely resemble bats in flight than swallows. The Vaux's Swift has drab gray/brown plumage and a very short tail (Fig. 13). Like the woodpeckers, swifts have stiff tails to aid in perching on vertical surfaces (Bull and Collins, 2007). The Vaux's Swift is found in Western North America (Fig. 14). 

Figure 14. Range map for the Vaux's Swift. [Image provided by eBird (www.ebird.org) and created 4 March 2017]

Diet

A study conducted by Bull and Beckwith (1993) analyzed food boluses delivered to nestling Vaux's Swifts and found the primary constituents were hoppers, aphids, whiteflies, flies, mayflies, ants, and parasitic wasps. One pair fed an average of 5,344 arthropods to their nestlings per day, totaling 154,976 arthropods during the nestling growth period! The study also used a technique called radio-telemetry to monitor Vaux's Swift foraging behavior and found Vaux's Swifts foraged primarily in forests and over water.

Management

Results from the North American Breeding Bird Survey indicate a 1.3% range-wide decline from 1966-2012 (Sauer et al., 2014). The Vaux's Swift is strongly associated with old growth forests (Manuwal and Huff, 1987). Vaux's Swifts are rarely observed on farms but have been observed foraging on farms with abundant surrounding forest. Hollow trees provide the majority of nest and roost sites, but chimneys may occasionally be used. Suitable cavities are created when one of several living tree species (Grand Fir [Abies grandis], Western Larch [Larix occidentalis], and Western red cedar [Thuja plicata]) with sufficient diameter at breast height have heart-rot fungi invade the heartwood. However, logging has resulted in a reduction in suitable trees for swifts, along with other notable species like the Spotted Owl (Strix occidentalis). Further, the number of chimneys have declined. Protection of forests and the use of nest boxes may aid in conservation. Bull (2003) describes here a nest box design that can be used.

More Resources

The Cornell Lab of Ornithology (birds.cornell.edu) supports a great citizen scientist network with detailed information on nest box construction and placement (nestwatch.org), recommendations on attracting species of interest (content.yardmap.org), and range information (ebird.org). The lab offers many opportunities for the public to get involved with scientific data collection through Project Feederwatch (feederwatch.org), eBird (eBird.org), and Nestwatch (nestwatch.org). Basic species information can be found at allaboutbirds.org, and the Merlin Bird ID app can aid in field identification.

This is the first article in a series about insectivorous birds on organic farms.

Western Bluebird

Chickadees and Warblers

References and Citations
  • Bael, S. A. V., S. M. Philpott, R. Greenberg, P. Bichier, N. A. Barber, K. A. Mooney, and D. S. Gruner. 2008. Birds as predators in tropical agroforestry systems. Ecology 89: 928-934. Available online at: http://onlinelibrary.wiley.com/doi/10.1890/06-1976.1/full (verified 13 April 2017).
  • Beal, F.E.L. 1918. Food habits of the swallows, a family of valuable native birds. Bulletin of the United States Department of Agriculture 619: 1-28.
  • Bent, A. C. 1942. Life histories of North American flycatchers, larks, swallows, and their allies. Bulletin of the United States National Museum 179.
  • Brown, C. R., and M. B. Brown. 1986. Ectoparasitism as a cost of coloniality in Cliff Swallows (Hirundo pyrrhonota). Ecology 67:1206-1218. Available online at: http://onlinelibrary.wiley.com/doi/10.2307/1938676/full (verified 15 December 2016).
  • Brown, C. R., and M. B. Brown. 1996. Coloniality in the Cliff Swallow: The effect of group size on social behavior. University of Chicago Press, Chicago, IL, USA.
  • Brown, C. R., and M. B. Brown. 1999. Barn Swallow (Hirundo rustica). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: https://birdsna.org/Species-Account/bna/species/barswa (verified 15 December 2016).
  • Brown, C. R., A. M. Knott, and E. J. Damrose. 2011. Violet-green Swallow (Tachycineta thalassina). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. USA. Available online at: https://birdsna.org/Species-Account/bna/species/vigswa (verified 15 December 2016).
  • Brown, C. R., and M. B. Brown. 2015. Ectoparasitism shortens the breeding season in a colonial bird. Royal Society Open Science 2:1-7. Available online at: http://rsos.royalsocietypublishing.org/content/2/2/140508 (verified 15 December 2016).
  • Bull, E. L. 2003. Use of nest boxes by Vaux's Swifts. Journal of Field Ornithology 74:394-400. Available online at: http://dx.doi.org/10.1648/0273-8570-74.4.394 (verified 3 January 2017).
  • Bull, E. L., and R. C. Beckwith. 1993. Diet and foraging behavior of Vaux's Swifts in Northeastern Oregon. The Condor 95:1016-1023. Available online at: http://www.jstor.org/stable/1369437 (verified 3 January 2017).
  • Bull, E. L., and C. T. Collins. 2007. Vaux's Swift (Chaetura vauxi). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: https://birdsna.org/Species-Account/bna/species/vauswi (verified 3 January 2017).
  • Buss, I. O. 1942. A managed Cliff Swallow colony in southern Wisconsin. Wilson Bulletin 54:153-161. Available online at: http://www.jstor.org/stable/4157143 (verified 15 December 2016).
  • Campbell, R. W., N. K. Dawe, I. McTaggart-Cowan, J. M. Cooper, G. W. Kaiser, M.C.E. McNall, and G.E.J. Smith. 1997. The birds of British Columbia. Vol. 3. Passerines: Flycatchers through vireos. University of British Columbia Press, Vancouver, BC, Canada.
  • De Jong, M. J. 1996. Northern Rough-winged Swallow (Stelgidopteryx srripennis). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: birdsna.org/Species-Account/bna/species/nrwswa (verified 2 January 2017).
  • Edson, J. M. 1943. A study of the Violet-green Swallow. The Auk 60: 396-403. Available online at: http://www.jstor.org/stable/4079262 (verified 15 December 2016).
  • Evans, K. L., and R. A. Robinson. 2004. Barn Swallows and agriculture. British Birds 97:218-230. Available online at: https://britishbirds.co.uk/wp-content/uploads/article_files/V97/V97_N05/V97_N05_P218_230_A001.pdf (verified 4 March 2017).
  • Hancock, D. D., T. E. Besser, D. H. Rice, E. D. Ebel, D. E. Herriott, and L. V. Carpenter. 1998. Multiple sources of Escherichia coli O157 in feedlots and dairy farms in the Northwestern USA. Preventative Veterinary Medicine 35:11-19. Available online at: http://www.sciencedirect.com/science/article/pii/S0167587798000506 (Accessed 4 March 2017).
  • Johnson, M. E., and M. P. Lombardo. 2000. Nestling Tree Swallow (Tachycineta bicolor) diets in an upland old field in Western Michigan. The American Midland Naturalist 144:216-219. Available online at: http://www.jstor.org/stable/3083024 (verified 2 January 2017).
  • Kragsten, S., E. Reinstra, and E. Gertenaar. 2009. Breeding Barn Swallows (Hirundo rustica) on organic and conventional arable farms in the Netherlands. Jounral of Ornithology 150:515-518. Available online at: https://link.springer.com/article/10.1007/s10336-009-0383-5 (verified 4 March 2017).
  • Krapu, G. L. 1986. Patterns and causes of change in a Cliff Swallow colony during a 17-year period. Prairie Naturalist 18:109-114. Available online at: https://pubs.er.usgs.gov/publication/1001567 (verified 15 December 2016).
  • Manuwal, D. A., and M. H. Huff. 1987. Spring and winter bird populations in a Douglas-Fir forest sere. The Journal of Wildlife Management 51:586-595. Available online at: http://www.jstor.org/stable/3801273 (verified 3 January 2017).
  • Mols, C. M., and M. E. Visser. 2002. Great Tits can reduce caterpillar damage in apple orchards. Journal of Applied Ecology 39: 888—899. Available online at: http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2664.2002.00761.x/full (verified 13 April 2017).
  • Nielson, E. M., M. N. Skov, J. J. Madsen, J. Lodal, J. B. Jespersen, and D. L. Baggesen. 2004. Vercytotoxin-producing Escherichia coli in wild birds and rodents in close proximity to farms. Applied Environmental Microbiology 70: 6944-6947. Available online at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC525191/ (verified 15 December 2016).
  • Norberg, R. A. 1994. Swallow tail streamer is a mechanical device for self-deflection of tail leading edge, enhancing aerodynamic efficiency and flight maneuverability. Proceedings: Biological Sciences 257: 227-233. Available online at: http://www.jstor.org/stable/50126 (verified 15 December 2016).
  • Orlowski, G., J. Karg, and G. Karg. 2014. Functional invertebrate prey groups reflect dietary responses to phenology and farming activity and pest control services in three sympatric species of aerially foraging insectivorous birds. PloS one 9: e114906. Available online at: http://dx.doi.org/10.1371/journal.pone.0114906 (verified 4 March 2017).
  • Samuel, D. E. 1969. House Sparrow occupancy of Cliff Swallow nests. Wilson Bulletin: 81:103-104. Available online at: http://www.jstor.org/stable/4159816 (verified 15 December 2016).
  • Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2014. The North American Breeding Bird Survey, Results and Analysis 1966-2013. Version 01.30.2015 USGS Patuxent Wildlife Research Center, Laurel, MD. Available online at: https://www.mbr-pwrc.usgs.gov/bbs/ (verified 2 January 2017).
  • Winkler, D. W., K. K. Hallinger, D. R. Ardia, R. J. Robertson, B. J. Sutchbury, and R. R. Cohen. 2011. Tree Swallow (Tachycineta bicolor). In P. Rodewald (ed.) The Birds of North America. Cornell Lab of Ornithology, Ithaca, NY. Available online at: https://birdsna.org/Species-Account/bna/species/treswa (verified 2 January 2017).

     

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 21859

Organicology 2015: Selected Live Broadcasts and Recordings from the Conference

lun, 2017/04/10 - 14:40

This broadcast took place on Friday, February 6, 2015, from the Organicology Conference in Portland, Oregon.

Crop Rotations for the Pacific Northwest

This workshop will present and discuss key crop rotations that include high demand/low supply crops that can be grown in the Pacific Northwest. This session will build on the Growing the Market Intensive and the work Oregon Tilth is doing to identify these crops and create a concrete picture of supply gaps and market opportunities. It will include a brief overview of the market analysis findings, and cover key considerations for producers to integrate these crops into current rotations, including acreage needs, variety selection, planting schedules, equipment, etc. The buyer will discuss how farmers can work with wholesalers to plan production and the producer will discuss the challenges and benefits of integrating new crops and her experiences working with buyers.

Speakers: James Henderson, Farm Liaison, Hummingbird Wholesale; Michael McMillan, Sourcing Manager, Organically Grown Company; Nick Andrews, Senior Instructor, OSU Center for Small Farms & Community Food Systems; Pete Postlewait, Co-Owner, Nature Fresh Farms

Soil Health in Organic Farming Systems

This discussion features experts from Washington State University and Rodale Institute who will present new research focused on improving soil health in organic systems. Participants will learn about soil health principles and practices for building healthy soils such as no-till and minimized tillage, cover crops, and crop rotations. This workshop will help organic and transitioning farmers identify soil health issues and improve soil health management on their farms. The workshop will also provide an overview of common soil health challenges for organic farmers and discuss the latest information on the topic from the National Organic Program and National Organic Standards Board. The session will cover information on federal conservation programs that provides financial and technical assistance for conservation projects.

Speakers: Mark “Coach” Smallwood, Executive Director, Rodale Institute; Doug Collins, Small Farms Educator & Soil Scientist, Center for Sustaining Ag & Natural Resources, WSU; Ben Bowell, Organic Education Specialist, Oregon Tilth & NRCS 

Seed Intensive Workshop

View selected recordings from this workshop here or on this YouTube playist:

  • Considerations in Organic Seed Production: Jared Zystro, Organic Seed Alliance
  • The Yearly Seed Production Cycle: Rowen White, Sierra Seeds
  • Seed Cleaning: Beth Ragourshek, Canyon Bounty Farm
  • Economics of Seed Growing: Steve Peters, Organic Seed Alliance; Andrew Still, Adaptive Seeds and Rowen White, Sierra Seeds

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 12903

April 2017

mer, 2017/04/05 - 15:40
In this Issue 
  • Upcoming eOrganic webinars
  • Where to learn about organic research
  • Sustainable agriculture scientists survey
  • Call for organic soil health and management abstracts
  • Comment period extended on organic check-off program
  • Videos about organic soybean and dry bean breeding
  • New spotted wing drosophila bulletin
  • Spotted wing drosophila videos
  • New report on CSA farms
  • Missed an Organic Farming Conference this Winter? Catch a Keynote
  • eOrganic mission and resources
Upcoming eOrganic Webinars April 6, 2017: Taking Stock of Organic Research Investments

This webinar will present the findings from the report by the Organic Farming Research Foundation:Taking Stock: Analyzing and Reporting Organic Research Investments: 2002-2014. This report provides information on the progress USDA funded organic research projects have made in addressing critical research needs. We will describe the types, locations, and impacts of USDA funded research, as well as research gaps and topics that require greater attention. The webinar will conclude with a set of recommendations for strengthening organic research in the US to best support the needs of organic farmers. Presenters are Diana Jerkins, Joanna Ory and Mark Schonbeck. Register

April 11, 2017: Use of High Glucosinolate Mustard as an Organic Biofumigant in Vegetable Crops

Brassica plants, including mustards, contain glucosinolates that, when broken down, produce compounds that can reduce weed pressure, insect pests, populations of parasitic nematodes, and soil-borne pathogens such as Pythium, Rhizoctonia, Sclerotinia, Verticillium, and Phytophthora. In this webinar, we’ll address the use of mustard cover crops that have been bred specifically to have high glucosinolate concentrations and act as a biofumigant in crops like potatoes, peppers, carrots, black beans, and strawberries.Webinar presenters include Heather Darby and Abha Gupta, University of Vermont Extension; and Katie Campbell-Nelson, University of Massachusetts. Register

Find all upcoming and archived eOrganic webinars at http://articles.extension.org/pages/25242/webinars-by-eorganic

Where to Learn about Organic Research

At conferences this past winter, we’ve spoken with farmers who tell me how much they enjoy learning about organic research through our webinars. However, there is still a feeling that it is hard to find information about organic research, especially since it is sometimes challenging to take time off the farm to meet researchers at a conference or field day, and online digging can be a hassle.

There is a great deal of free information about organic research available online. We’re listing some good sources in this list, including some free searchable databases, conference proceedings and recordings, and just a selection of the many university websites that have posted information on their organic research activities. Download it here: Where to Find Organic Research Information

Sustainable Agriculture Scientists Survey

The Union of Concerned Scientists is seeking information from experts to learn about their experience in sustainable agriculture research. This survey is intended for researchers or other professionals with an advanced degree (Master’s or Ph.D.) and with academic or professional experience that is relevant to sustainable agricultural systems. If you have questions about the survey or its use, please contact Tali Robbins at trobbins@ucsusa.org.

If you would like to take 15-20 minutes to fill out this voluntary survey, you can find it here

Call for Abstracts on Organic Soil Health and Management

The Organic Farming Research Foundation, in collaboration with the University of Florida-IFAS and the Florida Organic Growers & Consumers Association, invites submissions to the Organic Agriculture Soil Health Symposium (OASHS) for proposed research, education, and extension papers and posters.

The Symposium will take place during the Annual Tri-Societies Conference in Tampa, Florida in October 2017. The symposium invites researchers, extension, and educators from all disciplines related to organic farming and food systems, and other systems of sustainable agriculture that employ techniques compatible with organic standards.

Find out more information about the symposium, as well as the topics and submission requirements here: http://www.ofrf.org/news/call-soil-health-management-abstracts

Comment Period on Organic Check-Off Program Extended to April 19th

The Agricultural Marketing Service (AMS) is extending the comment period for the proposed establishment of an industry-funded research, promotion, and information program for certified organic products by 30 days, to April 19th, 2017. You can submit comments by going to Regulations.gov, and searching for "Organic Research, Promotion and Information Order", or by going to this direct link: https://www.regulations.gov/docket?D=AMS-SC-16-0112. You can learn more about the proposed program and some of the arguments both for and against it in the following articles from the MOSES Organic Broadcaster and NOFA Vermont Blog.

Videos about Organic Soybean and Dry Bean Breeding

Have you ever been curious about what goes on behind the scenes in organic field research? The University of Minnesota has created a series of videos, produced by Michael Winikoff and videography by Eve Daniels, that provides a unique perspective on recent research to improve organic soybean and dry bean production in the Upper Midwest. This research was part of the project Improving Soybean and Dry Bean Varieties and Rhizobia for Organic Systems funded through USDA's National Institute of Food and Agriculture (Grant Number 2011-51300-30743). The specific research objectives included:

  • Developing soybean varieties for organic systems
  • Developing improved varieties of dry bean for organic systems
  • Selecting improved strains of rhizobia for soybean and dry bean for organic systems
  • Evaluating the interactive effects of organic management practices with soybean and dry bean varieties

Learn more and watch the videos here.

New Organic Spotted Wing Drosophila Extension Bulletin for Michigan

A new Extension bulletin by Heather Leach, Matthew Grieshop and Rufus Isaacs of the Department of Entomology at Michigan State University details SWD biology along with recommendations on monitoring, cultivar selection, sanitation and exclusion, just to name a few! You can find the bulletin and read more updates from the NIFA OREI funded Spotted Wing Drosophila research project at https://eorganic.info/node/12848 

NCAP Spotted Wing Drosophila Videos

The Northwest Coalition for Alternatives to Pesticides hosted a webinar last year on Spotted Wing Drosophila management, and video clips from the webinar have been posted in both English and Spanish. Dr. Amy Dreves of Oregon State University presents important components to effective SWD management including: biology, identification, life cycle, early detection, and monitoring pest pressure. Multiple management approaches for each season are presented, with emphasis on preventative measures and cultural practices to minimize SWD population pressure. Find the videos here.

Note: We haven't reviewed these videos for organic certification compliance, so make sure, before using any pest control product in your organic farming system, to read the label to be sure that the product is labeled for the crop and pest you intend to control, and make sure it is legal to use in the stateor other location where it will be applied,and make sure that the brand name product is listed in your Organic System Plan and approved by your USDA-approved certifier.

New Report on Community Supported Agriculture (CSA) Farms

The Agricultural Marketing Service has produced a new report on CSA farms. highlighting six case studies of farmers using the community supported agriculture (CSA) direct-to-consumer business model and how that model has changed since the 1980s. Many CSAs use the traditional business model of a farmer or network of farmers offering consumers regular (usually weekly) deliveries of locally-grown farm products, particularly fruit and vegetables, during the growing season on a subscription or membership basis. The report shows that some CSAs have modified this model to include new products, partnerships and technology to create sustainable local food businesses. The report was prepared through a cooperative research agreement between USDA’s Agricultural Marketing Service (AMS) and the University of Kentucky. In addition to preparing the case studies, University of Kentucky researchers, led by principal investigators Timothy Woods and Matthew Ernst, conducted a national survey of CSA managers and operators and convened focus groups in the six states where the CSAs highlighted in the case studies are located.Find the report here.

Missed an Organic Farming Conference this Winter? Catch a Keynote

Many organic farming associations and groups across the U.S. offer annual conferences for a wide range of participants from commercial growers and ranchers to enthusiastic gardeners and homesteaders. Several conferences conducted over the past few months included internationally recognized and otherwise topnotch keynote presenters – here are just a few presentations available on YouTube:

  • Why We Need an Organic Future by Vandana Shiva. Delivered at the Northeast Organic Farming Association of Vermont Annual Winter Conference: https://youtu.be/gof7vdQI6OM
  • Farming Like We're Here to Stay by Fernando Funes-Monzote. Delivered at the Northeast Organic Farming Association of Vermont Annual Winter Conference: https://youtu.be/Ne5HNYGIt40
  • Organic Farming: The Next Generation by Mas Masumoto. Delivered at the Midwest Organic and Sustainable Education Service (MOSES) Farming Conference: https://youtu.be/kChOgyLYd78
  • Respect the Seed: Genetic Diversity by Matthew Dillon. Delivered at Eco Farm: https://youtu.be/Zc_b1YoLlBM
  • Food Justice: Challenges & Opportunities by Malik Yakini. Delivered at Eco Farm: https://youtu.be/duVs0uaPHPk

Many additional farmers, researchers, educators, and activists—like Liz Carlisle, Ricardo Salvador, K. Rashid Nuri, Eric Holt-Giménez, Donald Wyse, Fred Iutzi, and others--provided keynotes around the country to inform and inspire us as we enter the growing season.

eOrganic Mission

eOrganic is a web community where organic agriculture farmers, researchers, and educators network; exchange objective, research- and experience-based information; learn together; and communicate regionally, nationally, and internationally. If you have expertise in organic agriculture and would like to develop U.S. certified organic agriculture information, join us at http://eorganic.info.

eOrganic Resources

Find all eOrganic articles, videos and webinars at http://extension.org/organic_production

Connect with eOrganic on Facebook and Twitter, and subscribe to our YouTube channel!

Have a question about organic farming? Use the eXtension Ask an Expert service to connect with the eOrganic community!

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This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 22172

Video Series on Soybean and Dry Bean Research at the University of Minnesota

mer, 2017/04/05 - 13:57

eOrganic author:

Kristine Moncada, University of Minnesota

Have you ever been curious about what goes on behind the scenes in organic field research? The University of Minnesota has created a series of videos, produced by Michael Winikoff and videography by Eve Daniels, that provides a unique perspective on recent research to improve organic soybean and dry bean production in the Upper Midwest. This research was part of the project  Improving Soybean and Dry Bean Varieties and Rhizobia for Organic Systems funded through USDA's National Institute of Food and Agriculture (Grant Number 2011-51300-30743). The specific research objectives included:

  • Developing soybean varieties for organic systems
  • Developing improved varieties of dry bean for organic systems
  • Selecting improved strains of rhizobia for soybean and dry bean for organic systems
  • Evaluating the interactive effects of organic management practices with soybean and dry bean varieties

The first video provides an introduction to the project:

Project Overview: Improving Soybean and Dry Bean Varieties and Rhizobia for Organic Systems from BioTechnology Institute @ UMN on Vimeo.

Breeding Organic Soybean

Organic systems vary significantly from conventional systems, but until recently there have been few breeding programs specifically for organic systems. The first objective, led by the project's Principal Investigator Dr. James Orf, focused on breeding food-grade soybean and selection for traits that are important in organic systems in the Upper Midwest. See Dr. Orf's video interview below for more information about his project.

Video 2: Dr. Jim Orf—Improving Soybean Varieties for Use in Organic Systems from BioTechnology Institute @ UMN on Vimeo.

Breeding Organic Dry Beans

The second objective, led by co-Principal Investigator Dr. Thomas Michaels, also focused on organic breeding, but with dry beans rather than soybeans. Unlike soybeans, these legumes usually require supplemental nitrogen and are much less competitive with weeds. Improving these traits will offer organic producers another valuable legume option in their rotations. Dr. Michaels's work includes research on both heirloom and market class dry beans. His video interview is below.

Video 3: Dr. Tom Michaels—Market Class Beans from BioTechnology Institute @ UMN on Vimeo.

Dr. Michaels's interview continues in Parts 2 (https://vimeo.com/190706348) and 3 (https://vimeo.com/190719959).

Selecting Organic Rhizobia

Nitrogen is the most limiting nutrient in grain production. Increasing legume nitrogen fixation can not only improve the yields of organic leguminous crops, it can also improve the yields of other crops in the rotation. Our third objective addresses improving nitrogen fixation by using appropriately-matched rhizobial strains, which can counter lower fertility conditions that can exist in organic systems. This project was led by co-Principal Investigator Dr. Michael Sadowsky. For an introduction to his work, please see the video below.

Video 6: Dr. Michael Sadowsky: Improving Rhizobial Strains for Organic Soy and Dry Bean Production from BioTechnology Institute @ UMN on Vimeo.

Organic Bean Agronomic Practices

For the last objective, led by co-Principal Investigator Dr. Craig Sheaffer, research was conducted to study the interactive effects of variety characteristics of dry bean and soybean with mechanical weed control (tine weeding vs. cultivation), row spacing (30" vs. 15” row widths) and rotation sequence effects. An introduction to his project can be found below.

Video 1: Craig Sheaffer—Agronomic Practices for Improving Organic Soy and Dry Bean Production from BioTechnology Institute @ UMN on Vimeo.

On-farm Organic Research

Research conducted on organic farms was an important element for all the projects' objectives. Below is an interview with organic farmer Carmen Fernholz from Madison, MN, who discusses his experiences with participating in on-farm research with the University of Minnesota.


Video 7: Carmen Fernholz, On Farm Research for Organic Dry Bean and Soybean Cultivation from BioTechnology Institute @ UMN on Vimeo.

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 22262

Borgerding Dairy Farm: Organic Dairy Case Study

mar, 2017/04/04 - 14:12

eOrganic authors:

Emily Marriott, University of Illinois

Michelle Wander, University of Illinois

Source:

Joe Borgerding, Borgerding Dairy Farm

Introduction

After farming conventionally for over 20 years and dealing with some significant productivity, weed, and pest issues, Minnesota dairy farmer Joe Borgerding began to investigate biological farming and hasn't looked back since. Using mineral balancing, soil ripping, and cover crops, among other practices, Joe has improved his water infiltration and retention, soil quality, and crop productivity. His grass and wild proso millet weed problems and corn borer pests are also greatly reduced. Joe gives as much consideration to his livestock underground (soil biological organisms) as he does to his dairy herd. Describing his farm as organic by design, Joe continuously evaluates and adjusts his farming practices, striving to design a system where everything works together.

Figure 1. Field corn on the Borgerding Dairy Farm. Photo credit: Joe Borgerding, Borgerding Dairy Farm.

Farm History and Overview

Joe Borgerding began farming in 1974 when he took over management of his father's 50-head dairy herd. By 1978, he had purchased the farm's 360 acres and shortly thereafter increased the acreage to 400 with the purchase of some neighboring land. Most of his farming experience was acquired on this home farm, which Joe described as having had tight, anaerobic soils.

When Joe started farming, he used conventional methods. Over time, the farm experienced some significant productivity, weed, and pest issues. Regular soil testing did not reflect the problems he was having. According to Joe, he had “really pretty numbers, but ugly ground” due to chemical carryover, poor mineral balance, and poor soil structure. In 1996, Joe began to investigate other ways of farming. He worked with an agronomist who shared some new ideas, and also read material by William Albrecht and others. He began to focus on the biology of his soils, and worked to balance his soils by adding soluble calcium and sulfur in the form of fly ash and gypsum. He also started to transition the farm to organic production in 2000 and became certified organic in 2004. Compared to when he was farming conventionally, Joe finds that organic farming requires 50% more labor and twice as much management. Describing his farm as organic by design, Joe continuously evaluates and adjusts his farming practices, striving to design a system where everything works together.

The Borgerding Dairy Farm is located in central Minnesota in the warm summer, humid continental climate zone. Summers are warm and humid and winters are cold with heavy snowfall. The area receives about 28 inches of rain and 47 inches of snow per year. The farm includes a mix of soil types. The home farm has heavy clay loams (classified as Normania or Flom) and the additional owned and rented land is composed of dryland sand, irrigated sand, and peat ground.

Currently Joe, his wife Toni, and their two sons farm around 1080 acres—about 680 acres are owned and an additional 400 are rented. The family operates the farm together; Joe's sons manage the cows, allowing Joe to focus on crop production. The farm also employs Joe's daughter half-time, his nephew full-time and an additional full-time employee.

While primarily focused on dairy, they also raise some beef. The herd size is currently about 365 head, composed of 175 milk cows, 10 dry cows, 60 bred heifers, 80 younger heifers, and 40 beef. The cattle are supported by 220 acres of permanent pasture and an additional 70 acres of rotational alfalfa-grass meadows for hay and some grazing. The remaining acres are used to produce corn, soybeans, alfalfa, and small grains like oats and barley. Alfalfa is grown on 160 to 200 acres every year.

Milk and beef are sold to Organic Valley. Surplus hay is sold to area farmers. The majority of corn and grain is fed to cows and steers, and extra is sold to organic farmers and brokers. About 20% of the soybeans are roasted and fed on-farm as a protein supplement and the rest is sold.

Infrastructure and Technology

Joe invests in high-quality equipment and partially offsets the cost by performing around 500 acres of custom work (planting, chopping, tilling, and baling) for neighbors each year. This also gives other local farmers access to good equipment. Additionally, Joe has invested in a lot of tile drainage over the years.

Joe has made a significant investment in technology with the purchase of GPS, auto-steer, and yield monitoring. With the help of an agronomic consultant, Joe uses this technology to assist with on-farm research, experimentation, and recordkeeping. He is able to accurately track the locations of different practices and compare yields.

They now have radio collars on cows that monitor activity and rumination to detect when cows are in heat. The information is sent to the office so farmers know when cows are ready for breeding. With this technology, Joe no longer needs to feed and house a bull. This increases safety and widens their selection of bulls for breeding.

Key Practices Crop Rotations

Joe's crop rotations are complex and variable. Rotations and crops are selected based on soil type, irrigation, and proximity to the dairy operation. For example, silage corn is only grown on ground close to silage storage (Fig. 2); crops that require significant nitrogen (N) fertility are grown close to the manure lagoon; and more clover and alfalfa are grown on sandy soil. A major focus is on covering the ground early in the season. To that end, Joe is increasing his use of winter annuals like winter oats. Instead of having bare ground in April and May, winter annuals are growing as soon as the snow melts. This way he makes the most of early season sunlight while protecting soils year-round and reducing soil water loss.


Figure 2. An example of a feed crop rotation. This type of rotation would typically be used on heavier soils, close to the home farm. Trace minerals are applied before alfalfa to improve feed quality. The barley silage nurse crop provides a lot of tonnage, doesn't lodge, and allows them to get a second cutting of alfalfa.

Soil Fertility and Testing

Joe began pursuing alternative farming practices in the late 1990s to address productivity problems caused by salt and chemical carryover. These heavy clay loams were alkaline (pH up to 8) with high magnesium (Mg) base saturation (up to 35%). At that time, soils had poor aeration, infiltration, and root penetration and there were few earthworms. Joe applied fly ash to supply soluble Ca and S. He also conducted mechanical ripping of his cropland to break up the salt and chemical layer. Mineral balancing and a focus on soil biology, along with the recent addition of cover crops, have greatly improved his soil quality and productivity (Fig. 3).

Since the farm generates ample manure from the dairy operation, Joe prefers to fertilize with manure. Liquid manure has the highest amount of available N and is typically used on corn. Silage corn typically receives around 5,000 gallons liquid manure per acre, while shelled corn receives 6,000 gallons per acre. Pen manure that includes a lot of straw bedding is used on small grains like oats and barley. There is not enough manure produced on-farm to meet all of the fertility needs, so Joe annually applies up to 200 tons of poultry litter and potassium sulfate (K2SO4) on cropland located farther away from the home farm (up to 5 miles away). Some manure is partially composted on-farm and applied to pastures. Joe works with an agronomist to decide N fertilization rates, taking into account N from cover crops, alfalfa, and past manure use. He also uses nitrate testing of corn stalks in the fall to see if N was over- or under-applied to fine-tune their fertilization system. Joe finds that working with the agronomist is a helpful way to make sure nothing is missed.


Figure 3. With improvements in soil structure, corn root growth has improved. Photo credit: Joe Borgerding.

Gypsum is applied regularly to provide soluble calcium and sulfur on both cropland and pasture. To further balance minerals, Joe also pays attention to iron (Fe) and manganese (Mn) levels, aiming to have soil test values near 20 ppm for each. Over time, he has seen Fe levels decrease and Mn levels increase, as desired. A trace mineral blend is usually applied before alfalfa to improve feed quality. When farm finances can support it, Joe fertilizes pastures with a trace mineral blend that also includes humates.

Joe tests his soils every 3 to 4 years on both cropland and pastures. He uses soil tests as monitoring tools, but does not use them specifically to determine fertilizer amounts. His priority is to promote soil health and biological activity to mobilize the nutrients already present in his soil. He believes cover crop root systems and soil fungi are particularly important in increasing nutrient availability. Additionally, Joe uses feed tests to inform his soil management, believing they are a better way to evaluate the nutrient availability in his soils than soil tests alone.

Table 1. Soil test results (0-6") from 1996 and 2014 for selected fields and recent soil test results for selected pastures on the home farm.

 

Soil test results in Table 1 show the impact of Joe's mineral balancing efforts, in that Mg base saturation has decreased and Ca base saturation has increased in cropped fields. Iron and Mn levels have declined over time in cropland.

Joe is interested in new soil tests that provide information on soil biology. He does occasional humus and Solvita testing on existing fields and tests all new ground. Interpretations are still being developed for these tests and, while at this point Joe doesn't use them to make management decisions, he does want to have benchmarks for future use of these tests as interpretations improve.

Use of Cover Crops

In 2013, Joe started using cover crops in his annual forage crops. Now, cover crops are used extensively to improve soil quality and moisture retention. Joe believes that the improvements he has made in soil quality over the last 15 years could have been accomplished in 5 years if he had started using cover crops with the calcium and sulfur amendments.

Joe recently made a significant change in his cover crop practices. Formerly small grains like oats and barley were underseeded with a clover cover crop. After the grain was harvested, the clover would continue to grow and fix N. After growing for an additional 6 weeks, the clover was incorporated with manure. Now, Joe harvests the small grain, applies manure, and then seeds a cover crop mix. This new practice provides multiple benefits. It allows him to fine-tune his cover crop mix, depending on his goals for particular fields. He can incorporate the manure earlier, giving it more time to break down before winter, while also having a cover crop in place to take up mineralized nutrients. Additionally, he can seed the small grain heavier without needing to provide sunlight for the underseeded clover crop and if the small grain lodges, it doesn't smother the cover crop. Finally, using a winter cover gives Joe more time in spring, since some land is already planted. It is particularly helpful on river bottomland that tends to be wet and cold in spring. Joe also believes that soil with a cover crop has less frost and thaws more quickly in the spring, resulting in better infiltration of early spring rains. He is experimenting with strip tilling, expecting it to allow him to create a black berm for planting while leaving some of the cover crop intact.

Pest Management

Grass weeds have been virtually eliminated on the farm. Wild proso millet used to be a significant problem throughout the farm, but now occurs rarely. Joe attributes this to improvements in soil quality. Broadleaf weeds, such as pigweed and ragweed can still be problems, but are not hard to manage. Flaming is used to control some broadleaf weeds in corn. Use of auto steer and new weed control discs allows Joe to set the cultivator much closer to the crop rows, minimizing the need for harrowing. Cover crops are also part of Joe's weed control strategy.

Currently there are few major pest problems in the field crops. Corn borer used to be a significant pest when Joe was farming conventionally, but now is not a problem. According to Joe, they used to see more pests, but now they see more beneficial insects including lady bugs, lacewings, parasitic wasps, and dung beetles.

Grazing Practices

The herd is composed of 4 groups: dairy cows, dry cows, bred heifers, and beef cows. Each group is kept on a separate farm. Dairy cows are managed most intensively and get new pasture every day. The other groups are moved every 3 days or so. Dairy cows graze during the day, receiving at least 30% of their dry matter intake from pasture, and are housed in a freestall barn during the night. They receive grain, minerals, and corn silage as a total mixed ration in the barn in the mornings. Corn silage is an important source of starch to balance the high protein content of young grass and keep milk urea nitrogen levels down. The rolling herd average is 16,700 lb milk/cow/year with no purchased protein. The other cattle are primarily forage-based with some grain fed to young stock (3–5 lb/day). All feed, hay, and bedding is grown on the farm, and minerals are purchased.

Pastures are planted with cool-season perennials and are divided into 2–4 acre paddocks. During the summer, when pasture productivity is high, paddocks are divided in half with a break wire, but when pasture growth slows, cattle are given access to the entire paddock at once. Alfalfa is rotated throughout the farm's cropland, providing additional grazing during the summer slump when grass production slows. An additional 30–40 acres of alfalfa are usually strip grazed (2–3 acres at a time) each year after the second cutting of hay. In years with sufficient rain to keep pastures productive during the late summer, they may not need to graze these acres of alfalfa, but they provide additional flexibility.

Water is provided in the barn as well as in stock tanks near each paddock which are moved with the herds. Black plastic pipe is used to run water to the pasture with taps every 300–400 feet.

Pasture Renovation

Pastures are renovated when the species composition needs to be adjusted (e.g. too much bluegrass, thistles, or weeds) or when productivity seems to drop. To renovate, a pasture is tilled, pen or liquid manure is applied, and the field is seeded with warm season grasses—usually a sudangrass-ryegrass mix. Without the use of a summer annual, the old pasture mix would immediately regrow. The sudangrass-ryegrass mix also provides additional high-quality grazing in the late summer. In the fall, the pasture is reseeded with their pasture blend of clovers, grasses, ryegrass, and fescue. Approximately 10 acres of pasture are renovated each year. Weed and productivity issues may also be addressed through adjusting grazing practices (see the eOrganic webinar "Learning from Our Observations of Pastures & Livestock: Preventing Pasture Problems on the Organic Dairy Webinar by eOrganic").

Case Study Takeaway Points
  • Joe attributes improvements in soil quality to mechanical ripping, mineral balancing using calcium and sulfur amendments, and cover crops.
  • An emphasis on supporting the soil biological community guides farming system design and the use of year-round cover.
  • Investment in technology is expected to increase the effectiveness of on-farm experimentation.
References and Citations Additional Resources

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 17496

Taking Stock of Organic Research Investments Webinar

mer, 2017/03/22 - 18:27

Join eOrganic for a webinar about a report by the Organic Farming Research Foundation on USDA organic research investments. The webinar takes place on April 6, 2017 at 2PM Eastern Time, 1PM Central, 12PM Mountain, and 11AM Pacific Time. It's free and open to the public and advance registration is required.

Register now at https://attendee.gotowebinar.com/register/6702579283953605122

About the Webinar

This webinar will present the findings from the report by the Organic Farming Research Foundation: Taking Stock: Analyzing and Reporting Organic Research Investments: 2002-2014. This report provides information on the progress USDA funded organic research projects have made in addressing critical research needs. We will describe the types, locations, and impacts of USDA funded research, as well as research gaps and topics that require greater attention. The webinar will conclude with a set of recommendations for strengthening organic research in the US to best support the needs of organic farmers.

About the Presenters
  • Diana Jerkins, PhD is the Research Program editor at the Organic Farming Research Foundation
  • Mark Schonbeck is a research contractor at OFRF and is the lead author of the report
  • Joanna Ory is the Research Program Associate at OFRF.
System Requirements

View detailed system requirements here. Please connect to the webinar 10 minutes in advance, as the webinar program will require you to download software. To test your connection in advance, go here. You can either listen via your computer speakers or call in by phone (toll call). Java needs to be installed and working on your computer to join the webinar.  If you are running Mac OSU with Safari, please test your Java at http://java.com/en/download/testjava.jsp prior to joining the webinar, and if it isn't working, try Firefox or Chrome.

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 22204

Organic Seed Recordings from Organicology 2017

mar, 2017/03/14 - 11:51

In collaboration with the Organic Seed Alliance, eOrganic recorded three sessions on organic seeds at the Organicology Conference in Portland, Oregon on February 3, 2017. 

Got Seed?
  • Micaela Colley, Program Director, Organic Seed Alliance
  • David Lively, VP of Sales and Marketing, Organically Grown Company
  • Kristina Hubbard, Advocacy and Communications Director, Organic Seed Alliance
  • Laura Llewellyn, Produce Manager, Port Townsend Food Co-op
  • Barry Haynes, Produce Manager, Ashland Food Cooperative
  • Adam Wagner, Account Representative, Organically Grown Company

This workshop demonstrates the importance of organic seed to the success of the broader organic food trade, emphasizing the role that organic processing and retail businesses can play in ensuring farmers have the organic seed they need to meet market demand. Organic seed growers, plant breeders, farmers, produce retailers and food processors will talk about collaborations that ensure organic integrity along the entire production chain--beginning with organic seed.

Getting the Most Out of On-Farm Variety Trials
  • Jared Zystro, Research and Education Assistant Director, Organic Seed Alliance
  • Steve Peters, California Outreach Assistant, Organic Seed Alliance

Knowing how to conduct vareity trials can help farmers find the best varieties to grow for the farm and for the customer. Variety trials are also essential for farmer-breeders and seed growers dedicated to the continual improvement of seed. While properly conducted variety trials can be valuable, those not well planned do not provide meaningful results or are difficult to evaluate. Sometimes the plot layout is flawed, often the data collection is lacking, and very likely thhe farmer may become overwhlemed with other farm chores and the trial is neglected. This workshop will help farmers gather useful information through the fundamentals of field trial design and data collection without increasing labor and resource inputs. Presenters will share real life eamples of variety trial layouts, results and challenges.

In Celebration of Seeds
  • Laurie McKenzie, NW Research and Education Associate, Organic Seed Alliance
  • Don Tipping, Farmer and Seed Breeder, Seven Seeds Farm/Siskyou Seeds
  • Ken Greene, Managing and Creative Director, Hudson Valley Seed Library

Seed is the foundation of our food system and one of the true wonders of the world. It holds the potential to address some of our most pressing human and agricultural issues from climate change to nutrition, but it is also bridled in political and economic struggles. Today, in the midst of the media frenzy of biotech solutions, genetically engineered food, and transparency in labeling, the positive and heartwarming stories that inspire and empower us are often lost or overlooked. Join a handful of passionate seed stewards who have dedicated their lives to explanding biodiversity, protecting human rights to save seed, and preserving as well as creating new cultural traditions around seed. Their stories and images will leave you inspired by the power and hope held in the humble seed.

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 22160

Vegetable Production under High Tunnels on Crystal Organic Farm

mar, 2017/02/21 - 18:57

eOrganic authors:

Emily Marriott, University of Illinois

Michelle Wander, University of Illinois

Source:

Nicolas Donck, Crystal Organic Farm

This farm description is one of several developed for Ecological Soil Management, a course taught by Michelle Wander at the University of Illinois in the Fall of 2015 with support from Organic Valley. Additional farm descriptions from this course are Borgerding Dairy Farm: Organic Dairy Case Study and Grazing Acres Farm: Organic Dairy Case Study.

Introduction

Intensive year-round vegetable production under high tunnels is a cornerstone of Crystal Organic Farm. Farming in the Deep South, Nicolas Donck gravitated toward high-tunnel production because of its many benefits including less soil erosion from storm events, ability to achieve lasting soil quality improvements, and greater yields compared to his outside fields. He uses practices such as soil solarization and compost tea to manage pests and diseases and to improve high-tunnel vegetable production.

Overview of Farm

Nicolas Donck has been growing organic vegetables at Crystal Organic Farm in Newborn, Georgia (Newton County) for over 20 years. The farm encompasses a total of 175 acres, with 25 acres in field production and 1.5 acres under high tunnels. The rest of the farm consists of pasture, woodlands, and wetlands. Products include a wide assortment of vegetables, cut flowers, eggs, and some fruits, sold to a variety of direct and wholesale markets.

Climate and Soils

Located in north-central Georgia, about an hour southeast of Atlanta, Crystal Organic Farm is in a humid subtropical climate, classified as USDA plant hardiness zone 8a. The winters are mild, and summers are hot and humid. Annual precipitation, mostly falling as rain, totals about 47 inches spread evenly throughout the year. Cotton production was prevalent in this region during the late 1800's and early 1900's. Significant topsoil erosion occurred during this time, which still affects soil quality in the area. On Crystal Organic Farm, soils are generally classified as well-drained sandy loams and sandy clay loams with deep to very deep rooting depth, low natural fertility, and low organic matter.

Type of System

Year-round high-tunnel production takes center stage in this intensive mixed vegetable operation. Although high tunnels make up a small portion of the overall land in production, over half of farm labor is devoted to high-tunnel production, generating over half of the farm's revenue. With year-round production in the high tunnels, Nicolas is able to support a year-round staff of 15 people. He considers the high tunnels to be high-end real estate and spends more time and energy managing, monitoring, and scouting high-tunnel crops compared to those planted in the open fields.

Markets

Crystal Organic Farm sells to diverse markets with short value chains. Their biggest market, accounting for about 60% of sales, is the Morningside Farmers Market in Atlanta—a year-round market selling only certified organic produce. Nicolas was a founding member when the market started in 1995 and serves on their board of directors. Additionally, Nicolas sells directly to a handful of restaurants and to a small local distributor, which helps him limit the amount of time devoted to making deliveries. Crystal Organic Farm sells to Whole Foods Market on a small-scale basis, and also has a small year-round CSA with approximately 35 subscribers.

High-Tunnel Infrastructure

Nicolas says, “I can't praise high tunnels enough because they've really allowed us to grow our business. I'd advise people to build them.” Nineteen of Nicolas's 25 high tunnels are used in multi-bay systems comprised of 26 ft x 100 ft quonset-style tunnels that are connected along the long wall (Fig. 1). Nicolas also uses three long high tunnels (24 ft x 154 ft) that are not attached, but are situated about 2 feet apart. Finally, he has two 16 ft x 100 ft Atlas high tunnels, one of which is used for propagation. Additional structures include two shade houses (20 ft x 120 ft) made from pipe that was bent on-farm. Nicolas prefers wider tunnels over longer ones to increase airflow. Depending on orientation, long, narrow high tunnels tend to retain more humidity due to less air movement, which can lead to disease problems.

Figure 1. Crystal Organic Farm's multi-bay high tunnels consist of 26 ft x 100 ft quonset-shaped tunnels attached along the long walls. Photo credit: Nicolas Donck, Crystal Organic Farm.

End walls and side walls are removed in the summer months to provide ventilation and are replaced in the winter. On warm winter days, end walls can be opened like a curtain and then closed again at night (Fig. 2). According to Nicolas, “If it gets really cold we'll put a row cover inside to protect the more tender crops.”

 

Figure 2. Crops under high tunnel with end walls open. Photo credit: Nicolas Donck, Crystal Organic Farm.

With so many high tunnels, considerable work is involved in making sure everything is watered properly. Crystal Organic Farm uses good-quality well water for irrigation, and has not had problems with salt buildup in the soil. Nicolas recently installed an automatic drip irrigation system in the high tunnels that he can control from the barn. This system has greatly reduced labor and improved the timing of irrigation.

Nicolas uses the same size beds and space configuration in each of the tunnels, with 5-foot wide beds that run the length of the tunnel. A 4-row pinpoint seeder is used for direct seeding arugula, radishes, and baby turnips. A single-row seeder is used for carrots, beets, cilantro, and beans. All other high-tunnel crops are transplanted. Because high tunnels can be very humid, especially when they are closed up in the winter, Nicolas maintains adequate row spacing to discourage disease.

Roof plastic is replaced on the tunnels every four to six years. After six years, Nicolas notes that the plastic is quite dirty and light penetration is reduced. When deciding to replace roof plastic, Nicolas aims to strike a balance between maximizing the use to reduce costs and waste, and minimizing impacts on productivity from the increased shading.

Key Practices Drainage Around High Tunnels

Water running off of high tunnels must be managed to prevent erosion, water pollution, and flooding. Drainage can be an especially important management consideration with multi-bay or gutter-connected structures, and is most efficiently addressed at the construction phase prior to the installation of the tunnels. At Crystal Organic Farm, during new high-tunnel construction, trenches are dug along the outside edges and between attached high tunnels to provide drainage and keep the tunnels from flooding during large rain events (Fig. 3). The trenches are lined with landscape fabric. Nicolas notes, “A lot of water sheds off of those greenhouses so you want to plan for that. We have a fairly nice trenching system around the high tunnels to guide the water to a kind of retaining pond we have that's naturally there. We worked pretty extensively in trying to make sure that the water didn't flood the high tunnels.”

Figure 3. Trenches are dug between connected high tunnels and lined with landscape fabric to provide drainage and prevent flooding. Photo credit: Nicolas Donck, Crystal Organic Farm.

Crop Rotation

Nicolas doesn't follow a set crop rotation in the high tunnels, but instead adaptively manages based on how quickly the crops mature and any particular management or disease problems that might occur. He rotates crops by botanical family, with his primary goal being to keep two years between crops in the Solanaceae family (also called nightshades, which includes tomatoes, peppers, potatoes, and eggplants), and a year between other botanical families (Fig. 4). He keeps detailed notes specific to each bed, including crop, disease, and pest scouting information. The high tunnels are kept in production for as much of the year as possible. Once a crop is finished, the crop residues are removed and a new crop is planted right away, often in the same day. This leaves no time for cover crops, so fertility is maintained through the use of composts, commercial fertilizers like alfalfa meal, and compost teas (discussed in detail in the “fertilizer” section below).

Figure 4. An example of two years of crop production in a 5 ft x 100 ft high-tunnel bed at Crystal Organic Farm. Crop plant families are given in parentheses.

Cover Crops

Although cover crops are not used under the high tunnels, Nicolas uses them extensively in the fields. Commonly used summer covers are buckwheat, sudangrass, and cowpea. Sometimes the sudangrass and cowpeas are planted as a mixture. Nicolas likes buckwheat as a fast growing, flowering cover crop that provides nectar for bees and other pollinators, but it can quickly become a weed if it's allowed to drop seed. Winter cover crops are usually a mix of winter rye, spring oats, and Austrian winter peas. Winter cover crops are used on all fields that aren't growing a winter crop. Nicolas is planning to participate in a multi-state collaborative research project on using cover crops under high tunnels with the Universities of Kentucky, Tennessee, and Georgia.

Fertilization

High tunnels are usually installed over existing fields where the soil has already been improved by management. Local compost used to be the primary source of fertility, and the soil under new high tunnels would be amended with compost for the first two to three years.

Very often, fertility sources shift with changes in access to materials and costs. This is true for Nicolas who shared that “when I first started building high tunnels there was this company that made great compost. We used a tractor with a bucket-loader. In a typical high tunnel [we would use] two to three of those bucket loads in there. The company went out of business. Now I can get compost from further away, but [delivery] costs are so expensive that I'll buy maybe half a load and we'll use it around the farm, in pots and stuff, unless a bed is really bad… but it's site-specific, it's not like I'd do the whole [high tunnel].”

Currently, alfalfa meal (3-2-2) and compost tea are the primary soil amendments used under the high tunnels. Alfalfa meal is applied before each crop at a rate of about 2.5 lb/100 ft2 (33 lb/ac N, 22 lb/ac P2O5, and 22 lb/ac K2O) for each crop. Assuming five crops are grown each year, about 160 lb/ac N, 110 lb/ac P2O5, and 110 lb/ac K2O are applied each year under the high tunnels.

Nicolas also produces some compost on-farm, but does not manage it intensively enough to meet organic certification requirements for vegetable use, so it is used on fig trees or perennial crops. Outside fields receive a commercial pelletized poultry litter-based fertilizer (3-2-3).

Compost Tea

Compost tea is brewed on-farm and Nicolas's brewing methods have evolved over time. After starting with a 5-gallon bucket and an aquarium pump, he now uses a 15-gallon vortex brewer (Fig. 5) which provides increased aeration, an important factor in compost tea production. Nicolas uses only OMRI-approved ingredients in his compost tea. In a sturdy fabric sock, Nicolas combines 2-3 pounds of worm castings with 4 ounces of a mineral salt (SEA-90). The sock is dropped into the water with 4 ounces of liquid or powdered kelp (a good source of micronutrients) and 2 ounces of organic black molasses. The brewer runs overnight and the compost tea is used the next day. It should be noted that adding a sugar source when brewing compost tea needs should be done with care as it has the potential to result in the growth of any pathogens that may be present in the compost used. To prevent growth of pathogens, Nicolas relies on an OMRI-listed, non-manure-based, high-quality commercial worm casting product when brewing compost tea. Note: producers making teas need to use NOP approved practices and confirm that their methods are acceptable to their certifier because interpretations of the rules can vary. (For more information on compost tea, see the webinar, Making and Using Compost Teas).

Compost tea is applied through the drip tape irrigation system using a fertilizer injector. About two gallons of compost tea are diluted with three gallons of water. This 5-gallon dilution is applied to a single high tunnel (four 5 ft x 100 ft beds). Usually, each crop receives one application of compost tea, and the timing of application varies. Nicolas says, “I don't have a set schedule. It depends more on the crop. I used to do it once or twice or sometimes more if I felt the crop needed it, but now mostly once per crop. Tomatoes maybe we'd do a second time. It's more about how it all looks. If it looks like the plants need a little love, I'll give them some compost tea. But if they look strong and healthy and growing well I do not.” Outside fields also receive compost tea through drip tape or as a foliar application using a tractor-based pull-behind sprayer.

Figure 5. Compost tea brewing in a Vortex brewer at Crystal Organic Farm. Photo credit: Nicolas Donck, Crystal Organic Farm.

Soil Testing

Soil testing is not a regular practice on Crystal Organic Farm. When crops are growing well and he has few concerns about high-tunnel productivity, Nicolas relies on plant response and past practices rather than soil tests to inform his decisions about inputs. When he was relying more heavily on compost under the high tunnels, soil test results were instrumental in informing his decision to reduce compost application and turn to alfalfa meal. For soils under high tunnels that are kept covered year-round and thus not exposed to leaching rains, monitoring soluble salts on a regular basis by testing electrical conductivity is generally recommended. 

Soil tests taken in the spring of 2015 (Table 1) show distinct differences between the high tunnels and outside fields due to differences in management, particularly water management, and inputs. High-tunnel soils tend to have higher pH and organic matter than open fields. The buildup of Ca, Mg, and Zn in the high tunnels compared to the fields is likely due to the absence of leaching rains under the high tunnels. The high to excessively high P values under the high tunnels may be a legacy of past compost use. All soils tested medium to low for K. Based on these soil test results (Table 1), Nicolas is considering using a lower P fertility source under the high tunnels and adding additional K fertilizer.

Table 1. Spring 2015 soil tests (8” sample depth) for selected high tunnels and outside fields at Crystal Organic Farm.

      Mehlich I Extractant Sample pH OM P Ca K Mg Mn Zn     % ------------------------------- ppm ------------------------------ high tunnel 1 6.5 5.7 473 2777 54 194 20 14.6 high tunnel 2 6.4 5 480 2869 95 215 21 14.8 high tunnel 3 6.5 6.2 223 2274 76 190 20 7.6 high tunnel 4 6.6 5.4 260 2750 76 204 21 7.5 high tunnel 5 7.2 3.9 246 2172 47 160 19 6.4 high tunnel 6 6.8 3.5 218 1586 126 141 22 6.6 field 1 5.2 4.1 12 258 94 36 68 0.9 field 2 5 2.9 11 184 67 30 36 0.7 field 3 5.3 4.1 16 367 118 41 79 1.2

 

Soil Solarization

The hot summer months are used to solarize the soil in the high tunnels for four to six weeks (Fig. 6). Tunnels are solarized every two years—generally in the year before Solanaceous crops are grown. This is a key component of their weed control strategy. Nicolas also thinks solarization helps control disease, as problems that he has in field-grown crops seem to slowly go away under the high tunnels. 

Solarization is a process in which soil is covered with plastic to create high soil temperatures for four to six weeks. Benefits of soil solarization can include improved control of annual and perennial weeds, nematodes, and some soilborne diseases such as Southern blight (Chellemi et al., 1997; Ristaino et al., 1991). For more information, see Soil Solarization for Gardens and Landscapes and the University of California's website on soil solarization.

Figure 6. The ground under high tunnels is covered with clear plastic sheeting (right and left high tunnels) when undergoing soil solarization in the hot summer months. Photo credit: Nicolas Donck, Crystal Organic Farm.

Nicolas's soil solarization process starts with thoroughly cleaning out the beds and removing the weeds and crop biomass. Fertilizers such as alfalfa meal or compost are tilled in, then drip irrigation is put down. He makes sure that the irrigation is working and then puts the plastic down. Nicolas purchases a fairly thin (0.5 mm) plastic from a local hardware store. This is thinner than the 1 mm plastic recommended for solarization, but Nicolas prefers to minimize cost and waste, as this plastic is only used once. A strip of plastic covers two beds. The plastic is placed on the walkways as well, so it covers all of the soil in the high tunnel, not just the beds. Soil is then watered thoroughly. Water is essential to allow the system to heat and become anaerobic, although too much water has resulted in caky soil and algal growth under the plastic. He leaves the plastic on for four to six weeks, depending on the weather. The goal is to achieve 110-125°F daily maximum soil temperature in the top six inches. 

Weed Control Tactics and Tillage

Hand weeding is used in the high tunnels, and weeds are prevented from flowering as much as possible. Keeping low weed pressure in the high tunnels also helps to control disease. Even with landscape fabric lining, the drainage channels need to be weeded regularly to maintain performance and keep perennial weeds like Bermudagrass in check. In the high tunnels, a rototiller and sometimes a chisel plow is used to cultivate planting beds.

Pest and Disease Control

Nicolas does not use a regular spraying schedule in the high tunnels. He relies on frequent scouting for pests. Organic pesticides are used as a last resort after beneficial insects have been given a chance to control problems. Nicolas uses a variety of OMRI-approved products. Solarization, adequate row spacing, and low weed populations are all part of the disease-control strategy under the high tunnels.

Case Study Takeaway Points
  • Nicolas reports that production is better and easier under the high tunnels due to the ability to manage water, solarize the soil, prevent erosion, and better control diseases and weeds.
  • High tunnel production requires a significant investment of labor but also generates the majority of the revenue on Crystal Organic Farm. 
  • Nicolas takes advantage of the summer months when the high tunnels are too hot for many crops to solarize the soil, greatly reducing weed pressure under the tunnels.
  • Quick turnaround of crops, ventilation management, creative approaches to crop fertility, reducing fertilizer inputs over time, and careful observation are key strategies to successful high-tunnel production on this Georgia vegetable farm.
References and Citations Additional Resources

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 17413

Use of High Glucosinolate Mustard as an Organic Biofumigant in Vegetable Crops Webinar by eOrganic

ven, 2017/01/13 - 13:17

Join eOrganic for a webinar on April 11, 2017 on using high glucosinolate mustard as an organic biofumigant in vegetable crops. This webinar will take place at 2 PM Eastern Times, 1 PM Central, 12 PM Mountain, 11 AM Pacific Time. It's free and open to the public, and advance registration is required.

Register now at https://attendee.gotowebinar.com/register/8878799766349704962

 

About the Webinar

Brassica plants, including mustards, contain glucosinolates that, when broken down, produce compounds that can reduce weed pressure, insect pests, populations of parasitic nematodes, and soil-borne pathogens such as Pythium, Rhizoctonia, Sclerotinia, Verticillium, and Phytophthora. In this webinar, we’ll address the use of mustard cover crops that have been bred specifically to have high glucosinolate concentrations and act as a biofumigant in crops like potatoes, peppers, black beans, and strawberries.

About the Presenters

Webinar presenters include Heather Darby and Abha Gupta, University of Vermont Extension; and Katie Campbell-Nelson, University of Massachusetts.

Katie Campbell-Nelson is an Extension educator for the University of Massachusetts Vegetable Program with a background in soil and nutrient management and sustainable agriculture. She conducts research and provides educational programming for vegetable farmers in Massachusetts and is an editor of Vegetable Notes, a publication with practical and up-to-date research-based information for vegetable growers.

Dr. Heather Darby is an agronomic and soils specialist at the University of Vermont Extension where she conducts applied research and farmer outreach programs on farm-based fuel, cover crops and soil health, nutrient management, organic livestock forages, and grain production systems in the Northeast. She also operates a certified organic vegetable farm with her family in northern Vermont.

Abha Gupta is a crops and soils coordinator with the University of Vermont Extension Northwest Crops and Soils Program where she helps to conduct soil health research and nutrient management information on vegetable production systems.

System Requirements

View detailed system requirements here. Please connect to the webinar 10 minutes in advance, as the webinar program will require you to download software. To test your connection in advance, go here. You can either listen via your computer speakers or call in by phone (toll call). Java needs to be installed and working on your computer to join the webinar.  If you are running Mac OSU with Safari, please test your Java at http://java.com/en/download/testjava.jsp prior to joining the webinar, and if it isn't working, try Firefox or Chrome.

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 21771

Using Biofungicides, Biostimulants and Biofertilizers to Boost Crop Productivity and help Manage Vegetable Diseases

mar, 2017/01/10 - 18:16

Join eOrganic for a webinar on biofungicides, biostimulants, and biofertilizers! This webinar takes place on Thursday, March 30, 2017 at 2PM Eastern Time, 1PM Central, 12PM Mountain, and 11AM Pacific Time. It's free and open to the public and advance registration is required.

Presenters are Giuseppe Colla of Tuscia University in Viterbo Italy, MariaTeresa Cardarelli at the Italian Ministry of Agriculture and Forestry in Rome, Italy, and Dan Egel and Lori Hoagland of Purdue University.

Register now at https://attendee.gotowebinar.com/register/6332950960916838915

About the Webinar

Effectively managing diseases is one of the biggest challenges facing organic vegetable growers. A wide range of biologically based products are now available on the market that claim to boost crop growth and help plants withstand many plant diseases. However, there are few independent, scientifically-based studies to validate the efficacy of some of these products, and instructions detailing how and when to apply these products to achieve the best results are unclear. In this webinar, participants will describe the different types of products available in the marketplace today, provide an overview of recent studies evaluating their efficacy, and discuss strategies for identifying the most effective products and application practices.

About the Presenters

• Giuseppe Colla is an Associate Professor and Vegetable Physiologist in the Department of Horticulture at Tuscia University in Viterbo, Italy, and he is currently a visiting scholar at Purdue University. His current research interests include: biostimulant action of natural compounds to improve vegetable crop performance, especially under abiotic stress conditions. Current projects involve screening organic substances for biostimulant action on vegetable crops, optimizing the timing and rate of application, and understanding the mode of action of biostimulant products on plants.

• MariaTeresa Cardarelli is a Scientist and Plant Physiologist in the Research Center for Soil-Plant Studies at the Italian Ministry of Agriculture and Forestry in Rome Italy, and she is currently a visiting scholar at Purdue University. Her current research interests include: micropropagation, rhizogenesis and acclimatization in ornamental and aromatic plants; in vitro production of plant biomass for the extraction of secondary metabolites; and use of tissue culture for studying the interactions between biostimulants and plants.

• Dan Egel is an Associate Professor in the Department of Botany and Plant Pathology at Purdue University. His current research interests include: host resistance to anthracnose and Fusarium wilt of watermelon; managing fungicide resistance in foliar pathogens; and, management of vegetable diseases in greenhouses. Dan’s extension mission is to encourage the sustainable production of healthy vegetables through the use of integrated pest management and organic systems.

• Lori Hoagland is an Assistant Professor in the Department of Horticulture and Landscape Architecture at Purdue University. The goal of her research is to identify practical approaches to manipulate the plant microbiome, favoring beneficial microbial taxa that can help plants acquire nutrients and withstand biotic and abiotic stress. Current projects are aimed at biologically controlling plant and human pathogens, improving nitrogen-use efficiency, and mitigating uptake and bioavailability of heavy metals in vegetable crops.

 

System Requirements

View detailed system requirements here. Please connect to the webinar 10 minutes in advance, as the webinar program will require you to download software. To test your connection in advance, go here. You can either listen via your computer speakers or call in by phone (toll call). Java needs to be installed and working on your computer to join the webinar.  If you are running Mac OSU with Safari, please test your Java at http://java.com/en/download/testjava.jsp prior to joining the webinar, and if it isn't working, try Firefox or Chrome.

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 21749

Tomato Varietal Improvement

mar, 2017/01/10 - 18:09

Join eOrganic for a webinar about organic tomato breeding and variety improvement by some of the leading experts in this field! This webinar takes place on March 7th, 2017 at 2PM Eastern Time (1PM Central, 12PM Mountain, 11AM Pacific Time). It's free and open to the publica and advance registration is required. We hope you can join us!

Register now at: https://attendee.gotowebinar.com/register/2399952788384864002

Organic vegetable growers need varieties that are optimally adapted to their farming systems. In this webinar, participants will describe how to develop and select improved vegetable varieties using the breeding component of the tomato organic management and improvement (TOMI) project as an example. The goal of this project component is to develop new tomato varieties that are resistant to the most problematic diseases facing organic tomato growers, and have the good fruit flavor that customers expect from heirloom varieties. Specific topics will include: identifying key traits, choosing appropriate parents and a selection approach, making crosses, selecting from segregating populations for desirable traits, using genetic markers to aid in selection for key traits, and saving seed.

About the Presenters

• Julie Dawson is an Assistant Professor in the Department of Horticulture at the University of Wisconsin-Madison. Her background is in organic plant breeding and participatory research. Research topics include season extension methods, organic and participatory variety trials and variety selection for direct-market farms and gardens as well as extension resources for urban growers.

• Dan Egel is an Associate Professor in the Department of Botany and Plant Pathology at Purdue University. His current research interests include: host resistance to anthracnose and Fusarium wilt of watermelon; managing fungicide resistance in foliar pathogens; and, management of vegetable diseases in greenhouses. Dan’s extension mission is to encourage the sustainable production of healthy vegetables through the use of integrated pest management and organic systems.

• Lori Hoagland is an Assistant Professor in the Department of Horticulture and Landscape Architecture at Purdue University. The goal of her research is to identify practical approaches to manipulate the plant microbiome, favoring beneficial microbial taxa that can help plants acquire nutrients and withstand biotic and abiotic stress. Current projects are aimed at biologically controlling plant and human pathogens, improving nitrogen-use efficiency, and mitigating uptake and bioavailability of heavy metals in vegetable crops.

• Laurie McKenzie is the research and education assistant for Organic Seed Alliance (OSA). Laurie has over 10 years of experience in the organic farming and seed world, having spent considerable time doing both production and direct marketing. At OSA Laurie is involved in coordinating field work for breeding and variety trial projects, writing educational guides and materials, and co-teaching on-farm workshops.

• James Myers is a Professor of Vegetable Breeding and Genetics in the Department of Horticulture at Oregon State University. He works on a number of crops including dry and snap bean, edible podded pea, broccoli, pepper, tomato, winter and summer squash, and sweet corn. His main interest has been to improve vegetable varieties for disease resistance and human nutrition while maintaining quality and productivity in improved varieties.

• Kara Young is a graduate student studying Vegetable Breeding and Genetics under the direction of Jim Myers in the Department of Horticulture at Oregon State University. The focus of her research is developing late blight resistant tomatoes that are adapted to organic production. While at Oregon State University, Kara has been involved with the Tomato Organic Management and Improvement Project (TOMI) and the Northern Organic Vegetable Improvement Collaborative (NOVIC).

• Jared Zystro is the Research and Education Assistant Director for Organic Seed Alliance (OSA). He has worked in the organic seed industry for over 10 years, managing seed production at two farms and conducting research and education projects with OSA. In his work at OSA, he manages regional development in California, conducts participatory breeding projects and variety trials, and teaches farmers about seed production and plant breeding at workshops, conferences, and field days

System Requirements

View detailed system requirements here. Please connect to the webinar 10 minutes in advance, as the webinar program will require you to download software. To test your connection in advance, go here. You can either listen via your computer speakers or call in by phone (toll call). Java needs to be installed and working on your computer to join the webinar.  If you are running Mac OSU with Safari, please test your Java at http://java.com/en/download/testjava.jsp prior to joining the webinar, and if it isn't working, try Firefox or Chrome.

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 21748

Integrated Clubroot Management Strategies for Brassica Crops

mar, 2017/01/10 - 17:13

Join eOrganic for a webinar on clubroot management! The webinar will take place on February 15, 2017 at 2PM Eastern Time, 1PM Central, 12PM Mountain, 11AM Pacific Time. It's free and open to the public, and advance registration is required. Presenters are Aaron Heinrich and Alex Stone of Oregon State University.

Register now at: https://attendee.gotowebinar.com/register/4636044978955220481

About the webinar

Clubroot is a major soilborne disease of brassica crops worldwide (causal organism, Plasmodiophora brassicae), and disease incidence and severity have been increasing on lon-term organic farms in western Oregon. The disease occurs on most brassica family crops including broccoli, cabbage, cauliflower, turnip, rutabaga, and kale. In severe cases it can cause significant crop losses and heavily infested fields may be taken out of production. Thick walled resting spores of the pathogen have been shown to remain viable in soil for up to 20 years, making it difficult to eliminate the pathogen from an infested field. Therefore, once pathogen populations have developed to levels that cause economically damaging clubbing, the goal of the farmer is to manage rather than eradicate the disease. In this webinar we will explore the life-cycle of clubroot, environmental factors influence disease incidence and severity, prevention measures to minimize between field and in-field spread, and management strategies to reduce crop damage. Particular attention will be focused on soil pH management using lime because implementing an effective clubroot liming program is more challenging than liming for crop production.

About the Presenters

Aaron Heinrich is a Faculty Research Assistant in the Department of Horticulture at Oregon State University. He has an M.S. in Soils and Biogeochemistry from University of California at Davis and works on vegetable crop production issues including soil pH, nutrient, weed, irrigation, and soilborne disease management.

Alex Stone is a Vegetable Cropping Systems Specialist at the Oregon State University Department of Horticulture. She formerly worked as an organic vegetable farmer in Massachussetts.

System Requirements

View detailed system requirements here. Please connect to the webinar 10 minutes in advance, as the webinar program will require you to download software. To test your connection in advance, go here. You can either listen via your computer speakers or call in by phone (toll call). Java needs to be installed and working on your computer to join the webinar.  If you are running Mac OSU with Safari, please test your Java at http://java.com/en/download/testjava.jsp prior to joining the webinar, and if it isn't working, try Firefox or Chrome.

 

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

eOrganic 21747

High soil test phosphorus and potassium levels on a long-term organic farm: trends, causes, and solutions

mar, 2017/01/10 - 12:07

eOrganic authors:

Aaron Heinrich, Oregon State University

Jeff Falen, Persephone Farm

Alex Stone, Oregon State University

A trend observed on many organic vegetable farms that rely on imported manures and manure-based composts and fertilizers is an increase in soil test phosphorus (P) and potassium (K) levels above sufficiency (the level at which additional nutrient input is unlikely to increase yield or product quality). High soil test P levels are not detrimental to crops, but they do increase the possibility of off-farm P movement, primarily through sediment loss in runoff. Phosphorus that enters waterways may contribute to an increase in algal growth (eutrophication), which can ultimately result in death of aquatic organisms. High soil test K levels are not harmful to the environment, but can reduce plant calcium (Ca) and magnesium (Mg) uptake. If forage grown on high soil test K soils is fed to ruminant livestock (beef and dairy cattle and sheep), there is an increased risk of magnesium deficiency, which can result in the metabolic disease called grass tetany. A challenge for organic vegetable farmers over the long term is to develop a nutrient and soil management plan that does not generate high soil P and K levels.

Increasing soil organic matter (SOM) levels is often the primary goal of most organic farms' nutrient management programs because it is the reservoir that supplies nutrients to plants and soil organisms. To build or maintain SOM in intensively tilled vegetable production systems requires inputs of organic materials such as composts, manures, fertilizers, crop residues, and cover crops. The rate at which most organic fertilizers are applied is often based on crop nitrogen (N) requirements because N is typically the most limiting nutrient during most growing seasons, and yearly applications are often required. Many farms also routinely apply compost as a soil amendment, but not necessarily at agronomic rates (rates based on the nutrient requirement of the crop).

Although most organically managed systems primarily need only N, most organic fertilizers and amendments contain other nutrients. For example, chicken manure has a typical analysis of 4-3-3 (N-P2O5-K2O). Because plants require significantly more N than P, and often more N than K, adding a fertilizer such as chicken manure to meet crop N requirements will typically result in P and K applications in excess of crop needs. Over time, addition of P and K in off-farm composts and manures at rates that exceed crop removal will result in increasing soil test P and K levels. This happens because P and K are relatively immobile in most soils (i.e., will not be washed out of the root zone with irrigation or winter rains) and will build up over time.

Persephone Farm, an organic vegetable and poultry farm located in western Oregon, is used here as a case study to explore the relationship between the farm's nutrient management program and increasing soil test P and K levels. This farm was chosen because they have almost 30 years of rotation, nutrient management, and soil analysis data available, and their primary fertilizer source since they started farming has been off-farm chicken manure. Persephone is a diversified vegetable farm; however, in 2000 they integrated pastured laying chickens into their vegetable system.

The goal of this article is to explore the reasons for the increases in soil test P and K levels and to describe strategies for preventing further increases.

Farm Description

Persephone Farm has been certified as organic since 1985. In the 1970's and 1980's, the previous owners grew grains and peppermint on the land. Prior to that, the land was sheep pasture. Persephone Farm grows diversified vegetables on 21 acres. Their produce is sold at farmers markets and to restaurants and distributors. The soil on most of the acreage is a well-drained, deep, alluvial clay loam. The initial soil organic matter content averaged 2.8% across all fields during the first 5 years of organic management, but has since increased to an average of 5.2%. This increase is the result of annual additions of organic matter from cover crops, rotation into pasture, and off-farm manure additions. The farm consists of five fields of approximately 4.5 acres each.

Persephone Farm adheres to a fairly strict four year rotation; vegetables are grown for three years, followed by one year in pasture. The pasture mix (red clover, ryegrass, and oats) is planted in the fall of the third year of vegetable production, and is taken out in the spring approximately 20 months later. If a late vegetable crop or early rains prevent pasture establishment, the field goes into cover crops in that year (typically Sudan grass). Ten to twenty-five percent of the acreage is in pasture at all times. Persephone also grows other summer and winter cover crops.

In 2000, Persephone added laying hens to their operation that are grazed year-round. The flock size fluctuates from 100 to 300 laying hens. The chickens are split into two flocks, each of which is pastured in a quarter-acre of fenced ground. These fenced areas are moved every 2-3 weeks through pasture, cover crops, and post-harvest fields, but they spend most of their time in pasture.

Nutrient Budgeting

Persephone Farm historically relied primarily on imported, minimally-processed or composted poultry litter for crop nutrient supply. However, due to food safety issues as well as availability, they now primarily use pelleted chicken manure (4-3-3) and feather meal (12-0-0). A yearly estimate of nutrients coming onto the farm from 2004–2010 in poultry manure and other specialty fertilizers is shown in Figure 1. The average rate of P2O5 and K2O applied to all fields over this time period was 55 and 67 lb/acre, respectively.


Fig. 1. Average annual fertilizer K2O and P2O5 applied (lb/acre) from 2004 to 2010 to Persephone's five fields.

A new source of off-farm nutrients entered the system when laying chickens were introduced in 2000. The chickens' foraging diet is supplemented with commercial laying rations, cracked corn, and a small amount of kelp meal. The farmers estimate that 30–50% (varies seasonally) of the chicken manure is collected in the laying house and not returned to farm fields (it is applied to a private garden). Some nutrients are exported in eggs and poultry carcasses. Estimated egg production is 3,000 dozen eggs per year. The chicken feed nutrient balance is given in Table 1. 

Table 1. Annual nutrient balance from poultry operation

 

P2O5

K2O

Nutrient Inputs/Outputs lb/acre/year5

Imported onto farm in feed1

11

7

Exported in eggs2

1

<1

Exported in poultry carcasses3

<1

<1

Manure removed from laying house (40%)4

4

3

Retained in Fields 6 4

(1) Laying ration (16,538 lb/yr; 3.35-0.55-0.70) + corn (1,875 lb/yr; 1.23-0.39-0.47)
(2) 3,000 dozen large eggs @ 228 mg P2O5 and 77 mg/K2O per egg
(3) Assuming 200 dry lbs of stewing chicken sold per year (8% N, 1%P, and 0.75% K; University of Delaware)
(4) A portion of this manure is collected and applied to a private garden (not returned to fields)
(5) This is averaged over 21 acres though only about 6 acres per year actually receive manure from the laying flock. Over time, these nutrients are evenly distributed over the farm.

Estimates of P and K removed in the harvested crops are given in Table 2. These estimates are based on realistic yield potentials for vegetables grown in Oregon, however, nutrient removal may vary greatly depending on variety, growth habit (i.e., bush peas vs. pole peas), extended harvest in greenhouses, disease pressure, etc. Average P2O5 and K2O uptake is estimated to be 27 and 113 lb/acre, respectively, though there is a wide range in uptake between crops.

Table 2. Estimates of P and K removal of select vegetable crops

Crop

Yield

P2O5

K2O

 

ton/acre

lb/acre

Broccoli

8

20

110

Cabbage

30

55

230

Carrots

15

25

100

Cauliflower

6

20

60

Cucumber, slicing

10

10

40

Lettuce, Romaine

20

30

170

Onion, bulb

34

50

160

Peas, shelled, bush

2

10

20

Peppers, bell

20

30

110

Potatoes

20

60

250

Snap beans, bush

6

15

40

Spinach

12

15

120

Squash, summer

20

30

130

Squash, winter

18

20

120

Sweet corn

10

30

60

Tomato

12

10

80

 

Avg

27

113

Table 3 shows the nutrient balance of P and K entering the farm in fertilizer and chicken feed minus outputs in harvested vegetables and poultry products. Phosphorus entering the farm exceeded crop removal by 34 lb P2O5/acre/yr. For K, removals exceeded inputs by 44 lb K2O/yr. However, these data should be interpreted with caution because the actual crop mix and acreage and yields of each crop were not accounted for, and an average of crop removal was used (Table 2). Overall, the P and K contribution from the poultry operation is relatively minor, providing approximately 17% and 10% of the total P2O5 and K2O, respectively, of imports.

Table 3. Nutrient budgets for P and K 

 

 

P2O5

K2O

 

 

lb/acre/yr

Inputs

From chicken feed (Table 1)

11

7

 

55

67

 

subtotal

66

74

Outputs

Exported from poultry operation (Table 1)

5

3

Estimated crop removal in harvested product (Table 2)

27

113

 

subtotal

32

116

 

Remaining in field

34

-42

(1) Average of all fields from 2004 to 2010

Soil P and K Trends

After almost three decades of annual off-farm nutrient applications, soil test P and K have increased to levels well above those needed to maintain optimum crop growth (Fig. 2). For most vegetable crops, the sufficiency level (the concentration at which a crop response to nutrient addition is highly unlikely) for P (Bray 1P method) and K (ammonium acetate method, equivalent to Mehlich III) is 75 and 250 ppm, respectively. Based on available soil test records, average initial soil test P and K levels in the late 80's and early 90's were already at or above sufficiency (Fig. 2). Since then, soil test P and K have more than doubled in most fields, and current levels are very high. Even though Persephone has been reducing P fertilizer inputs (Fig. 1), inputs still exceed outputs (Table 3). The decline in K since 2008 suggests that more K is being removed than imported, which is supported by the nutrient budget.

This case study highlights the value of soil testing at regular intervals, as well as good recordkeeping. For an individual field, there can be a high amount of variability between soil sampling dates (Fig. 2). This is due to inherent sampling variability, which may be affected by a number of factors including how it is collected, the number of subsamples, when it is collected (i.e., shortly after a fertilizer addition), etc. Due to this variability, multiple years of sampling at regular intervals is necessary for long term trends to appear. It is like the stock market—short term volatility does not necessarily indicate where the market is heading, but trends do emerge over the long term. Thirty years of soil testing reports combined with soil amendment records allowed us to identify trends.

The farmers estimate that their current nutrient application rates are 50% lower than the rates they applied when they first started farming. For example, in the early years (1988–1995) they applied 3 to 6 tons/acre chicken manure on cucumbers, but they now apply <2 tons/acre. Data from 2004 to 2010 show that off-farm K2O and P2O5 inputs have declined by 44% and 34%, respectively (Fig. 1). Despite reduced P inputs, P is still applied in excess of crop needs and soil test P is continuing to increase (Fig 2).

Figure 2. Soil nutrient trends for potassium (ammonium acetate method; left) and phosphorus (Bray 1P method; right) on select fields in the surface 8 inches. The dashed red line indicates the level that is considered to be sufficient for most crops. When soil test levels are higher than sufficiency, additional nutrient inputs are unlikely to increase yield or product quality.

Soil Processes Controlling Soil Test P and K Levels

In the first 5–10 years of farming, soil P and K levels remained relatively unchanged even though they were applying larger quantities of off-farm chicken manure than they do now (Fig.2). However, soil test P and K levels began rising rapidly in subsequent years (Fig.2). The buffering capacity of the soil may explain this change in rate. In this context, the buffering capacity is the ability of the soil to resist change in soil test P and K levels from applied fertilizer. In general, soils have a larger buffering capacity against change when soil test P and K values are low.

When the Persephone farmers started farming, it is likely that P was strongly adsorbed to Al and Fe oxide minerals, and K to the silicate clays. Once the adsorption sites were saturated, additional P and K was held less tightly, thereby increasing the test levels to a greater degree than additions when P and K contents were low and P and K were strongly adsorbed. For example, it likely takes less P to increase the soil test from 50 to 100 ppm than to increase from 20 to 50 ppm. Research conducted by McCollum (1991) on P decline following cessation of 30 years of annual P fertilizer additions supports this theory. He reported a logarithmic decline (i.e., initially very fast as the weakly adsorbed P was removed by crops, then much slower as the strongly adsorbed P was removed) in soil test P due to crop P removal. This may explain why soil test P and K levels continued to rise at the same time that the farmers reduced fertilizer applications over the last 10 yrs. Even though soil P and K levels were already high when they started farming, adsorption sites were likely not yet saturated.

Another contributing factor to increasing soil test K levels may be the increase in soil organic matter (SOM). Since they started farming, SOM at Persephone has increased by approximately 85%. Because SOM has a high cation exchange capacity (CEC), an increase in SOM content increases the soil's capacity to store cations such as K+. The laboratory test used to determine potential K availability measures the K+ cations adsorbed on clays and SOM. Assuming the ratio of exchangeable Ca, Mg, and K has remained constant, the 2.4% SOM increase (absolute increase) could theoretically increase soil test K level by 100 ppm (this assumes a CEC of OM=200 meq/100g and K comprising 5% of OM CEC).

In addition to the increase in SOM content, part of the increase in K may be due to the rotation into pasture. The plants in the pasture rotation, particularly legumes which are high in K, may be mining subsurface K and depositing it at the surface. Because the plants in the pasture are in the ground for a long period of time, they are able to form deeper, dense root systems capable of translocating subsurface soil K into the soil surface, potentially resulting in an accumulation of K in the plow layer.

Solutions

Increasing SOM is often the primary nutrient management goal of most organic farms. However, the use of off-farm inputs to meet this goal may be in conflict with a farm's environmental and sustainability objectives due to the increase in soil test P and K levels above those needed for optimum crop growth. To align a nutrient management program with farm values and production goals requires careful planning to either prevent elevated P and K levels from occurring, or to reduce current levels.

Prevention is the best solution. When first starting to farm a field organically, larger applications of compost and manures may be warranted to increase SOM, but only if initial P and K levels are below sufficiency (<75 and 250 ppm, respectively). Once sufficiency has been reached, an attempt should be made to balance imports of P and K with exports. It will be necessary to grow N–fixing cover crops, or to rotate into pasture to supply sufficient N to meet crop needs yet maintain or increase SOM without adding P or K.


If fields already have high soil test P and K, a list of practices that can be used to maintain or reduce levels are given in Table 4. Many years may be required to observe a measured decrease in soil test P using these practices, though on very high P soils the initial change may be more rapid (McCollum, 1991; Kratochvil, 2006).

Table 4. Practices for maintaining or reducing soil test P and K levels 

Practice

Benefits

Constraints

Grow a forage crop that will be sold to an off-farm animal operation

Removes P and K from system

If the ratio of K/(Ca+Mg) in the plant is >2.2 or in the soil is >0.06, this indicates a high potential for grass tetany if forage is fed to ruminants (Elliott, 2008)

Grow N-fixing winter cover crops (legumes)

Provides N to meet crop needs without increasing soil test P or K; typically the cheapest source of organic N relative to other organic fertilizers

Weather may not permit timely planting or spring incorporation; may not be compatible with early vegetable planting dates

Make compost from on-farm organic materials

Cycles nutrients on the farm without increasing P and K

Requires experience and equipment

Grow vegetables with high P and K removal in harvested product

Removes P and K from system

Opportunity cost of growing a potentially less profitable crop; lack of a market to sell product

Meet crop N demands with N-only fertilizers such as feather meal (13-0-0) or fertilizers with a high N analysis relative to P and K.

Supplies N without adding P and K in excess of crop needs

Cost - many of these specialty fertilizers are more expensive per pound of plant available N (PAN) compared to cover crop or manure PAN

Nutrient budgeting (match inputs with outputs)

Maintains soil test P and K

Time consuming when growing a diversity of crops; uncertainty in estimating crop uptake and removal

Conclusions

Soil P and K levels on Persephone Farm have increased well above those needed for optimum crop growth. This is the result of almost three decades of off-farm chicken manure and fertilizer applications that exceeded nutrient removal in the harvested product. Due to the high P and K content of chicken manure relative to N (and the relatively limited soil mobility of P and K), these nutrients have accumulated in the soil resulting in elevated soil test P and K levels. Nutrient inputs from purchased chicken feed were less significant (17% and 10% of total P2O5 and K2O, respectively) than those from off-farm chicken manure.

The Persephone farmers estimate that their current nutrient application rates are 50% lower than when they first started farming. Soil testing indicates that this reduction may be responsible for declining soil test K levels. But even at current application rates, P is still being applied in excess of crop removal, and soil test P continues to increase. In response to elevated P and K, the farm now uses more feather meal to meet crop N needs. Although the farm would like to use more feather meal, they are limited by its cost and availability, and they also have concerns about the sustainability of feather meal as a nutrient source. Due to low crop P removal in harvested products relative to K, reducing P levels may take decades. Balancing nutrient inputs and outputs is necessary to create an environmentally sustainable nutrient management program.

References and Citations

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

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