Soil & Fertility
Organic Agriculture Projects at WSU
Organic Farming Systems and Nutrient Management. Beginning in 2002, organic amendments, cover crops, and soil quality have been investigated in our farming systems experiment. An interdisciplinary team is studying a range of issues important to small scale, direct-market, and organic agriculture, including nutrient management, and soil quality, weed management, economics, marketing, and on-farm research.
Using Local Sources of Organic Nutrients. Use of organic materials from livestock farms and recycled urban waste streams can help improve soil productivity and reduce nutrient imbalances, and can contribute to the sustainability of local agriculture.
Composts and Nutrient Management. Composting stabilizes organic wastes which affects available nutrient levels in soil, often causing short term immobilization (tie-up) of nitrogen, but a long term slow release. Effects of compost applications on nitrogen availability and soil properties have been evaluated in various studies at WSU Puyallup.
Soil Quality. A series of measurements was begun in 2004 to assess selected soil physical and biological properties in a variety of cropping and management systems. Measurements include bulk density, soil compaction, soil organic matter, and aggregate stability. Biological measurements began in 2005.
WSU Publications
Mustard green manures are being used in irrigated regions of Eastern Washington to improve soil quality, control wind erosion, and manage soil-borne pests. On-farm research has been conducted since 1999 to determine the benefits of these crops and to improve their effectiveness.
Compost Connection newsletter. WSU CSANR. 1996–2000.
Soils and Soil Testing. Links for farmers and gardeners to resources on soil sampling, soil testing, and soil test interpretation.
Systematic method for rating soil quality of conventional, organic, and integrated apple orchards in Washington State. J.D. Glover, J. P. Reganold, P.K. Andrews. 2000. Agriculture, Ecosystems, and Environment 80:29-45.
Organic and biodynamic management: effects on soil quality. L.Carpenter-Boggs, A.C. Kennedy, J.P. Reganold. 2000. Soil Sci. Soc. Amer. J. 64:1651-1659.
Effects of biodynamic preparations on compost development. L.Carpenter-Boggs, J.P. Reganold, A.C. Kennedy. 2000 Biological Agric.and Horticulture 17:313-328.
Comparison of soil properties as influenced by organic and conventional farming systems. J.P. Reganold. 1998. Amer. J. Alternative Agr. 3:144-155.
Reduced nitrate leaching and enhanced denitrifier activity and efficiency in organically fertilized soils. S.B. Kramer, J. P. Reganold, J.D. Glover, B.J.M. Bohannan, and H.A. Mooney. 2006. Proc. Natl. Academy Sciences 103:4522-4527.
Soil and plant mineral nutrition and fruit quality under organic, conventional, and integrated apple production systems in Washington State, USA. P.K. Andrews, J.K. Fellman, J.D. Glover, J.P. Reganold. 2001. Acta Hort. 564:291-298.
Significance of gravimetric versus volumetric measurements of soil quality under biodynamic, conventional, and continuous grass management. J.P. Reganold, A.S. Palmer. 1995. J. Soil Water Conservation 50:298-305.
Resources
Building Soils for Better Crops. 2000. F. Magdoff and H. Van Es. Sustainable Agriculture Network.
Organic Fertilizer Calculator. An Excel based tool to help you determine how much nutrient value various organic amendments have, how quickly they release N, and how much they cost. Check the on-line guide for details or look at the presentation from the WA Hort 2007 meeting.
Managing Cover Crops Profitably. 1998. Sustainable Agriculture Network.