A fertile soil should be capable of supplying all the elements plants need for growth. Fertility is an essential component of soil health and productivity. Not only must nutrients be present in the soil, they need to be in a form the plant can use. Since these ionized forms of nutrients are soluble in water, plant roots can absorb them along with the water they take up. The rate at which nutrients become available is affected by weather, irrigation, soil type, pH, and fertilizer applications. Nutrients present in forms other than ions are not directly available to plants although they do represent reserves that can become available in the future.
Differentiating the Value and Cost of Compost Across Likely Farm Use Scenarios in Western Washington
Hills, K., Brady, M., Yorgey, G., Collins, D. 2019. A technical report completed as part of the Waste to Fuels Technology Partnership. 17 pp.
Nutrient Recovery: Products from dairy manure to improve soil fertility
Benedict, C., J. Harrison, S. Hall, G. Yorgey. 2018. Washington State University. FS305E.
Weddell, B., T. Brown, K. Borrelli. 2017. Chapter 8 In Yorgey, G. and C. Kruger, eds. Advances in Dryland Production Systems in the Pacific Northwest. Washington State University Extension, Pullman, WA.
Yorgey, G., W. Pan, R. Awale, S. Machado, A. Bary. 2017. Chapter 7 In Yorgey, G. and C. Kruger, eds. Advances in Dryland Production Systems in the Pacific Northwest. Washington State University Extension, Pullman, WA.
Soil Fertility Management
Borrelli, K., T. Maaz, W. Pan, P. Carter, H. Tao. 2017. Chapter 6 In Yorgey, G. and C. Kruger, eds. Advances in Dryland Production Systems in the Pacific Northwest. Washington State University Extension, Pullman, WA.
Phosphorus Uptake by Potato from Fertilizers Recovered from Anaerobic Digestion
Collins, H. P., E. Kimura, C. S. Frear, and C. E. Kruger. 2016. Agron. J. 108:2036-2049. doi:10.2134/agronj2015.0302
Soil physical properties, nitrogen, and crop yield in organic vegetable production systems
Cogger, C, A. Bary, A. Fortuna, L. Myhre, and D.P. Collins. 2016. Agronomy Journal. 108:1142-1154
Cover crop effects on light, nitrogen, and weeds in organic reduced tillage
Wayman, S., C. Cogger, D. P. Collins, C. Benedict, I. Burke, and A. Bary. 2015. 39:6, 647-665, DOI: 10.1080/21683565.2015.1018398
The Rationale for Recovery of Phosphorus and Nitrogen from Dairy Manure
Yorgey, G., C. Frear, C. Kruger, T. Zimmerman. 2014. WSU Extension Fact Sheet FS136E. This fact sheet is part of the AD Systems Series.
Precision Nitrogen Application: Eric Odberg Case Study
Yorgey, G., S. Kantor, K. Painter, H. Davis, and L. Bernacchi. 2014. Video and text farmer case study. Eric Odberg is a fourth generation farmer who practices no-till management and was an early adopter of variable rate nitrogen (VRN) application in the dryland production region of the Pacific Northwest.
Management to Reduce Nitrous Oxide Emissions in Organic Vegetable Production Systems
Cogger, C., A. Fortuna, D. Collins. Feb 27, 2014. The second of a two-part webinar series.
Why the Concern about Nitrous Oxide Emissions?
Cogger, C., A. Fortuna, D. Collins. Feb 25, 2014. The first of a two-part webinar series.
The influence of cover crop variety, termination timing, and termination method on mulch, weed cover, and soil nitrate in organic reduced-tillage
Wayman, S., C. Cogger, C. Benedict, I. Burke, D. P. Collins, and A. Bary. 2014. Renewable Agriculture and Food Systems. FirstView: 1-11. http://dx.doi.org/10.1017/S1742170514000246.
Soil Fertility in Organic Systems: A Guide for Gardeners and Small Acreage Farmers
Collins,D. C. Miles, C. Cogger, R. Koenig. 2013. Pacific Northwest Extension Publication PNW646.
Soil Testing: A Guide for Farms with Diverse Vegetable Crops
Collins, D. 2012. Washington State University Extension. EM050E.
Composts and Nutrient Management
The WSU Puyallup Research Center faculty have conducted extensive work on compost, manure and biosolids. This website provides information on yard waste and food waste composts, clopyralid, calculating bulk density, nutrient management for organic systems and compost facility operator training events. The site has links to the Compost Mix Calculator the Organic Fertilizer Calculator and Center research publications.
Northwest Soil Science: Nitrogen Mineralization
Soil Scientist Doug Collins published an article on Readthedirt.org that explains his research on how and when soil nutrients are available to crops.
Building Markets for Biofertilizers — Perceptions and Performance
Video of keynote address by Chad Kruger at the 26th Annual BioCycle West Coast Conference April 2012.
Helping Sustain Agriculture in Africa
WSU scientist Lynne Carpenter-Boggs is working with an international group of scientists to help find bean varieties and microbial inoculates that will improve yields on the ancient soils that farms in many parts of Africa must contend with. Dr. Carpenter-Boggs took a Flip camera to Africa and shot some wonderful footage of farms, people and animals.
A Fine Thin Skin – wind, water, valcanoes and ice
Steury, 2011. Article highlighting CSANR soil research in Washington State Magazine.
Potential nitrogen contributions from legumes in Pacific Northwest apple orchards
Mullinix, K. and Granatstein, D. 2011. Intl. J. Fruit Sci. 11:74-87.
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 smale scale, direct-market, and organic agriculture, including nutrient management, soil quality, weed management, economics, marketing, and on-farm research.
Organic Fertigation Products – April 2010
Article in Sustaining the Pacific Northwest Newsletter
Influence of biodynamic preparations on compost development and resultant compost extracts on wheat seedling growth
Reeve, J.R., L. Carpenter-Boggs, J.P. Reganold, A.L. York, and W.F. Brinton. 2010. Bioresource Technology.
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.
Land Application – A true path to zero waste?
Organic Waste to Resources Research and Pilot Project Report. Brown, S., K. Kurtz, C. Cogger and A. Bary, March 2010. Ecology Publication Number 09-07-059. This study tested the benefits of compost and biosolids applications to soils. Benefits included increased C and N levels, improved soil bulk density, water holding capacity and crop yield.