Cover crops are a "bio" technology that is underutilized in contemporary U.S. agriculture. Cover crops can serve many purposes on a farm, including nutrient conservation, soil erosion control, improved water infiltration and quality, reduced weed and pest pressure, increased biodiversity, and better soil quality. Many plants can be used as cover crops, such as rye, clovers, sudangrass, mustard, buckwheat, and lupine. They can be grown between cash crops when soil would normally be bare, or integrated into cash crops through relay planting or intercropping. There is considerable information on cover crops from prior to the 1950s that is applicable today. In addition, current research and experience with cover crops is opening opportunity for new ideas such as direct seeding grains into cover crops and cover crops for bioremediation of soil-borne diseases.
Cover crops in orchards and vineyards
WSU Tree Fruit Research and Extension Center webpage. Contains links to additional resources and presentations.
BIOAg Conferences and Proceedings
The BIOAg program has hosted or contributed to a number of conferences and symposia. Materials resulting from these events include presentations, posters, and proceedings highlighting research progress and results. Materials prepared for conferences often precede formal publications so browse here for emerging research.
Potential nitrogen contributions from legumes in Pacific Northwest apple orchards
Mullinix, K. and Granatstein, D. 2011. Intl. J. Fruit Sci. 11:74-87.
Sustainability trade-offs in organic orchard floor management
Granatstein, D., Wiman, M., Kirby, E., Mullinix, K. 2010. Acta Hort. 873:115-122.
Influence of orchard floor management and compost application timing on N partitioning in organically managed apple trees
TerAvest, D., J.L. Smith, L. Carpenter-Boggs, L. Hoagland, D. Granatstein, and J.P. Reganold. 2010. HortScience. 45:637-642.
Research knowledge and needs for orchard floor management in organic tree fruit systems
Granatstein, D. and E. Sanchez. 2009. Intl. J. Fruit Science 9:257-281.
Mulching options for Northwest organic and conventional orchards
Granatstein, D. and K. Mullinix. 2008. HortScience 43(1):45-50.
Using Leguminous Cover Crops as a Nitrogen Source for Organic Grape Production - September 2005
Article in Sustaining the Pacific Northwest Newsletter
Reduced Tillage in on Organic Farms Virtual Field Day
WSU researchers and extension educators are researching different methods for reducing tillage in organic vegetable production. This video demonstrates termination of barley and vetch cover crops with a roller/crimper and flail mower.
Comparing tillage and mulching for organic orchard performance
Wiman, M., Kirby, E., Granatstein, D., Mullinix, K. 2008. Poster presented at 2008 BIOAg Research Symposium.
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National resource links
The following online resources contain a wealth of information on a number of BIOAg topics. Use search fields to narrow results:eXtension, USDA Alternative Farming Systems Information Center, National Sustainable Agriculture Information Service (ATTRA) Master Publications List, Sustainable Agriculture Research and Education (SARE) Project Reports, & Natural Resource, Agriculture and Engineering Service (NRAES) Publications.
Managing Cover Crops Profitably
This publication explores how and why cover crops work and provides all the information needed to build cover crops into any farming operation. Revised and updated in 2007, the 3rd edition includes new chapters on brassicas and mustards, six new farm profiles, as well as a comprehensive chapter on the use of cover crops in conservation tillage systems. Updates throughout are based on more than 100 new literature citations and consultations with cover crop researchers and practitioners around the country. Appendices include seed sources and a listing of cover crop experts.