Skip to main content Skip to navigation
Washington State University - Puyallup Organic Farming Systems and Nutrient Management

Recursos en Español

Recursos en Español

 

♣ Recursos para Productores Latinos – Nuestro Programa de Agricultores Latinos apoye a productores para que sus negocios agrícolas tengan éxito. Enfocado en el Noroeste de Washington, ayudamos a productores a profundizar su conocimiento a través de talleres y cursos, escribir un plan de negocios y un plan total de granja, solicitar prestamos y subvenciones, conectarse con mercados y compradores y explorar nuevos productos de valor agregado y más.

♣ Publicaciones en Español de la Universidad Estadal de Washington.

♣ Publicaciones en Español de la Universidad de la Estadal de Oregon.

♣ Publicaciones en Español de la Universidad de Idaho.

 

 

 

 

Soil Quality


Soil Quality

Soil Quality Project, Carnation, WA.

In 2006 we initiated a project at Full Circle Farm in Carnation, WA to describe how soil texture affects the soil food web. To create a detailed soil texture map and see how this inherent soil parameter affected other parameters we took 81 samples across a 62-acre area of FCF. From each site we analyzed soil texture, bulk density, nitrogen, organic matter, and the soil food web.

Soils within the area of the farm sampled varied greatly in texture. There was a strong gradient of increasing sand and decreasing clay from west to east. Sand ranged from 5-54 % while clay ranged from 9-27%. Four texture classes were identified: sandy loam, loam, silt loam, and silty clay loam.

At the field scale we found that much of the variation in nematode population density could be explained by recent tillage, not soil texture. However, sampling in 2007 was designed to control for management effects so we sampled from one field in a sandier area of the farm and one in a more clay-rich area. The sandier field had more than 8 times the number of nematodes as the clay-rich field. Also, within the sandy field, where clay ranged from 10-17%, clay was strongly negatively correlated with the number of nematodes. On the other hand, in the clay-rich field (16-31% clay) there was no correlation between clay and the number of nematodes.

We conclude that within certain ranges the variation in soil physical and chemical properties can affect biological populations. Thus, careful mapping of inherent soil quality parameters should be the first step in monitoring soil biological populations.

♣ Soil Community Structure, Function, and Spatial Variation in an Organic Agroecosystem (PDF-Online, Full Report). D. Collins.

This project was funded by a graduate student research grant from the ♣ Western Sustainable Agriculture Research and Education Program.

Satellite map of Full Circle Farm.

Full Circle Farm soil texture map, percent sand.

Full Circle Farm soil texture map, percent clay.

Full Circle Farm soil texture map, texture class.

Organic Farming

Organic Farming Projects

Overview:

WSU Puyallup has 12 acres of certified organic farming research land and several more acres of non certified land that has been managed organically. Current and past experiments include the Organic Farming Systems experiment, cover crop trials, climate change gas experiments, food safety, pastured poultry, and improving no till and minimum tillage methods.

Research areas:

♣ Organic Farming Systems for Vegetable Crop Production

In 2002 we began the Organic Farming Systems experiment, an integrated research program focused on sustainable and organic production systems for small-scale, direct-market vegetable crop production. Our goal is to work with farmers to develop management systems that utilize local inputs to produce high-quality, high-value crops efficiently and profitably in an environmentally sustainable manner.

♣ Using Local Sources of Organic Nutrients

Using locally available organic materials (manures, yard wastes, etc) reduces nutrient imbalances and improves soil productivity.  Information on managing such materials including nutrient availability, equipment compatibility, potential side effects, economics.

♣ Cover Crops

We have been working with winter and summer cover crops to find varieties most effective at reducing weeds in later crops. Cover crops reduce erosion, improve soil structure, and provide organic matter and nitrogen to the soil. Research results and photo essays.

♣ Soil Quality

We measured soil physical and biological properties in a variety of crop and management organic farming systems to see how they affected the soil quality over time. Looked at were soil texture, bulk density, nitrogen, organic matter, microorganisms, and their relationships.

♣ Pastured Poultry

We raised slow and fast growing Cornish Cross poultry in our Organic Farming Systems plots.  They provided nutrients to the soil for the vegetables grown during the cash crop part of the pasture/crop rotation, as well as income during the pasture part of the rotation. Included are moveable cage plans and comparisons of the different Cornish Cross varieties.

♣ Farmer Focus Groups: Soil Fertility and Water Quality

Online PDF Summary of three focus groups with organic and conventional Western Washington Farmers held in 2002.  The objective of a focus group is not to reach consensus or make decisions, but to simply gain the greatest possible understanding of the topic from the perspective of all participants.  Topics included Soil Fertility, Cover Crops, Soil Testing, Stream Bank Management and Water Quality.

Slideshows, Photos, and Webinars:

♣ Photo Gallery from certified organic research land (HTML-Online)

♣ Soils and Fertilizer (72 slides, PDF-Online, use browser down scrollbar to advance slides).  Soil physical properties, fertilizers, soil amendments, cover crops.

♣ Introduction to Summer Cover Crops (16 slides, PDF-Online, use browser down scrollbar to advance slides)

♣ Closing the Recycling Loop Through Organic Amendments in Agriculture and Gardens (Webinar-Online, Original broadcast date 5 Jan 2011. Slow loading, please wait till after “check our troubleshooting…” goes away.  Needs Flash Player to run which is not available on Apple products).

Current & Past Project Support:

♣ USDA Integrated Organic Program CSREES

♣ WSU Center for Sustaining Agriculture and Natural Resource Organic Program

♣ Western Region SARE Grants No. GW06-011, SW03-040

♣ USDA IFAFS Grant No. 2001-52101-11349

 

Links:

♣ WSU Center for Sustaining Agriculture and Natural Resources, information, publications, links, events, programs.

♣ Cultivating Success, sustainable small farm information for Washington and Idaho.

♣ Food Systems (integrates former Small Farms), information, calendar, resources, programs.

♣ Oregon State University Cover Crops Bulletins,  A series of bulletins that describes the uses and management cover crops grown in the Pacific Northwest

♣ Managing Cover Crops Profitably, 3rd ed., Free ebook download or purchase hardcopy. Published by USDA Sustainable Agriculture Network. This publication summarizes research data and farmer evaluations of cover crops grown across the United States.

♣ University of California Sustainable Agriculture Research and Education Program Cover Crop Resource Page

♣ Nutrient Management Guide: Sweet Corn (PDF-Online). For both conventional and organic growers.

♣ Nutrient Management Guide: Silage Corn (PDF-Online).

Publications:

♣ Soil Physical Properties, Nitrogen, and Crop Yield in Organic Vegetable Production Systems (PDF-Online). Cogger. C.G., A.I. Bary, E.A. Myhre, A. Fortuna, and D.P. Collins. 2016.  Agron. J. 108:1142-1154. doi:12.2134agronj2015.0335

♣ Potential Carbon Sequestration and Nitrogen Cycling in Long-Term Organic Management Systems (PDF-Online). Bhowmik, A. Fortuna, L.J. Cihacek, A.I. Bary, P.M Carr, and C.G. Cogger. 2016.  Renewable Agric Food Sys. doi:10.1017/S1742170516000429

♣ Use of Biological Indicators of Soil Health to Estimate Reactive Nitrogen Dynamics in Long-Term Organic Vegetable and Pasture Systems (PDF-Online). Bhowmik, A. Fortuna, L.J. Cihacek, A.I. Bary, and C.G. Cogger. 2016.  Soil Biol. Biochem. 103:308-319.

♣ Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance Under Organic Management (PDF-Online). Lawson A., C. Cogger, A.Bary, A. Fortuna. 2015. PLoS ONE 10(6): e0129597. doi:10.1371/journal.pone.0129597

♣ Cover Crop Effects on Light, Nitrogen, and Weeds in Organic Reduced Tillage (PDF-Online).  Wayman, S., C.G Cogger., C. Benedict, D.P. Collins, I Burke, and A.I Bary. 2015. Agroecology and Sustainable Food Systems, 39:647-665. doi: 10.1080/21683565.2015.1018398

♣ The Influence of Cover Crop Variety, Termination Timing, and Termination Method on Mulch, Weed Cover, and Soil Nitrate in Reduced-Tillage Organic Systems (Request pdf e-copy). Wayman, S., C. Cogger, C. Benedict, I. Burke, D. Collins, and A. Bary. 2014. Renewable Agric Food Sys. doi:10.1017/S1742170514000246

♣ Soil Fertility in Organic Systems – A Guide for Gardeners and Small Acreage Farmers (Request pdf e-copy). Collins, D. C. Miles, C. Cogger, and R. Koenig. 2013. Pacific Northwest Extension Publication PNW 646.

♣ Nitrogen Contribution of Rye-Hairy Vetch Cover Crop Mixtures to Organically Grown Sweet Corn (Request pdf e-copy). Lawson, A., A. M. Fortuna, C.G. Cogger, A.I. Bary, and T. Stubbs. 2012. Renew. Ag. Food Sys. 28:59-69. Available on CJO doi:10.1017/S1742170512000014.

♣ Farm-Scale Variation of Soil Quality Indices and Association with Edaphic Properties (Request pdf e-copy). Collins, D.P., C.G. Cogger, A.C. Kennedy, T. Forge, H.P. Collins, A.I. Bary, and R. Rossi. 2011. Soil Sci. Soc. Am. J. 75:580-590.

♣ Management Effects on Soil Quality in Organic Vegetable Systems in Western Washington (Request pdf e-copy). Pritchett, K., A.C. Kennedy, and C.G. Cogger. 2011. Soil Sci. Soc. Am. J. 75:605-615.

♣ Nutrient Management Guide: Sweet Corn (Western Oregon) (PDF-Online). For both conventional and organic growers. Hart, J.M, D.M. Sullivan, J.R. Myers, and R.E. Peachey. 2010. Oregon State University Extension Service. EM9010-E.

♣ Nutrient Management Guide: Silage Corn (Western Oregon) (PDF-Online) For both conventional and organic growers. Hart, J.M., D.M. Sullivan, M. Gamroth, T. Downing, and A. Peters. 2009. Oregon State University Extension Service.  EM8978-E.

♣ Estimating Plant-Available Nitrogen Release from Manures, Composts, and Specialty Products (Request pdf e-copy). Gale, E.S., D.M. Sullivan, C.G. Cogger, A.I. Bary, D.D. Hemphill, and E.A. Myhre. 2006. J. Environ. Qual. 35:2321-2332.

♣ Fertilizing with Manure and Other Organic Amendments (PDF-Online). Bary, A., C. Cogger, and D.M. Sullivan.  2016.  PNW0533.  Washington State University Cooperative Extension, Oregon State University Cooperative Extension System, US Department of Agriculture.

♣ Fertilizing Farmland with Yard Trimmings from Landscape Maintenance (PDF-Online). Bary, A.I., C.G. Cogger, and D.M. Sullivan. 2016. FS222E. Washington State University Extension.

♣ Soil Management for Small Farms (PDF-Online). Cogger, C.G.  2000.  EB 1895.  Washington State University Cooperative Extension, Oregon State University Extension Service, University of Idaho Cooperative Extension System, US Department of Agriculture.

Cover Crops

Cover Crops

Overview:

Cover crops are used to supply fresh organic matter to soils, improve soil structure, fix nitrogen, cycle nutrients, protect soil from erosion, and as a tool to manage weeds and other pests. Choice and management of cover crops depends on which benefits are most important, and on the cropping system.

Our research has been focused on fall-planted and relay-planted cover crops.  We have evaluated the effects of different fall-planted rye vetch blends, planting dates, and incorporation dates on ground cover, winter weed competition, and nitrogen supply to the subsequent crop.  Relay planting is the planting of cover crops between rows of the cash crop during the summer or early fall. Our relay cover crop research was focused on establishment, survival, ground cover, and N supply capability of legumes interseeded into standing vegetable crops.  Recent research is focused on cover crop management in reduced tillage organic systems.

Cover Crops Photo Essays:

Interseeded cover crop demonstrations over various dates:

Organic Systems Experiment over various dates:

Publications:

♣ Nitrogen Contribution of Rye-Hairy Vetch Cover Crop Mixtures to Organically Grown Sweet Corn (PDF-Online).  Lawson, A., A. M. Fortuna, C.G. Cogger, A.I. Bary, and T. Stubbs.  2012.  Renew. Ag. Food Sys. 28:59-69.  Available on CJO doi:10.1017/S1742170512000014.

♣ Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance Under Organic Management (PDF-Online). Lawson A., C. Cogger, A.Bary, A. Fortuna. 2015. PLoS ONE 10(6): e0129597. doi:10.1371/journal.pone.0129597

♣ Cover Crop Effects on Light, Nitrogen, and Weeds in Organic Reduced Tillage (PDF-Online).  Wayman, S., C.G Cogger., C. Benedict, D.P. Collins, I Burke, and A.I Bary. 2015. Agroecology and Sustainable Food Systems, 39:647-665. doi: 10.1080/21683565.2015.1018398

♣ The Influence of Cover Crop Variety, Termination Timing, and Termination Method on Mulch, Weed Cover, and Soil Nitrate in Reduced-Tillage Organic Systems (PDF-Online). Wayman, S. C. Cogger, C. Benedict, I. Burke, D. Collins, and A. Bary. 2014. Renewable Agric Food Sys. doi: http://dx.doi.org/10.1017/S1742170514000246

Local Organic Nutrients

Using Local Sources of Organic Nutrients

Overview:

Nutrient imbalances present problems in urban fringe watersheds, with an oversupply of local organic nutrients in some areas of the watersheds. 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. A number of barriers exist to more widespread and efficient use of local organic materials in agriculture. These include concerns about availability of supplies relative to application timing, consistency of materials, compatibility with equipment and farming practices, economic questions, and potential side effects such as weeds, pathogens, and odors. A key issue is the need for better information on nutrient availability. In 2004 we completed a 3-year field and laboratory research project studying nitrogen availability from a range of composted and uncomposted local organic amendments. Research was done at WSU and OSU.  Results of this research are used for guidance for organic nutrient management in the Northwest.

♣ Organic Fertilizer Calculator – Downloadable Excel Worksheet for calculating organic fertilizer rates, developed at Oregon State University using the results of this research and subsequent laboratory research by Dan Sullivan at OSU.

Local organic nutrients being spread on a farm field

Publications

♣ Estimating Plant Available Nitrogen Release from Manures, Composts, and Specialty Products (Request pdf e-copy).  Gale, E.S., D.M. Sullivan, C.G. Cogger, A.I. Bary, D.D. Hemphill, and E.A. Myhre. 2006. J. Environ. Qual. 35:2321-2332.

♣ Predicting Plant-Available Nitrogen from Organic Amendments in the Second Year after Application (PDF-Online).  Kusonwiriyawong, C., D.M. Sullivan, D.D. Hemphill, C.G. Cogger, A.I. Bary and E. Myhre. 2014. Acta Hort. 1018: 325-333.

Manure

Manure as a Resource

Overview:

The separation of animal agriculture from crop production has led to accumulation of excess manure on livestock farms. Crop farms can benefit from this manure as a source of nutrients and organic matter, if the manure is suitable for their needs and shipping does not make the cost prohibitive. We have assessed the nutrient values of different sources of manure and their suitability for crop production (see “♣ Predicting Nitrogen Availability for Organic Amendments“). Our publication “♣ Fertilizing with Manure and Other Organic Amendments” is a guide for crop farmers for evaluating manure sources, and testing and applying manure.

Horse Manure and Soil Nitrogen

Horse manure is an abundant, locally available source of organic matter for soils.  A major concern about horse manure is that it can cause a nitrogen deficiency when added to soils, leading to stunted, yellowed crops.  In a study of 36 farms and stables in King County we measured nitrogen levels in horse manure (see: “♣ Horse Manure and Soil Nitrogen“).

Managing Dairy Manure to Protect Water Quality

Water quality problems, changing herd management patterns, and increased regulation have made manure management a critical issue for dairy farmers. Our immediate goal is to help dairy farmers improve the use of manure to increase agronomic benefits and reduce the risk of over-application, runoff, and leaching. Our long-term goal is to help farmers identify chronic nutrient imbalances, and develop ways to reduce nutrient imports or increase exports. We have done research on 1) rate and timing of dairy slurry applications to forage grass, 2) pre-sidedress nitrate testing for corn, 3) whole-farm flows on dairies. Manure application rates have traditionally been based on nitrogen, but phosphorus has emerged as the nutrient of concern in many watersheds.

Links:

♣ Manure Spreading Advisory Page – Manure Application Risk Management for the Puget Sound.  When can you apply manure anywhere in the Puget Sound region, given current conditions?  Interactive, specs based on: time of year, current weather forecast for your farm, individual field conditions.

♣ Oregon State University Nutrient Management, Dan Sullivan. Focus is on nutrient management for animal manure and other organic by-products.

♣ A Horse Owner’s Guide to Good Stewardship.   R. James, Ohio State University, good soil and water stewardship practices for horse owners.

♣ Environmental Stewardship for Small-Scale Animal Producers. This is a series of fact sheets on topics including manure management, pastures, runoff, protecting water quality, animal mortalities, and environmental stewardship for horse owners. This link includes an opportunity to review these bulletins and share your comments with the authors.

Publications:

♣ Fertilizing with Manure and Other Organic Amendments (PDF-Online). Bary, A., C. Cogger, and D.M. Sullivan. 2016. Washington State University Cooperative Extension, Oregon State University Cooperative Extension System, US Department of Agriculture. PNW0533.

♣ Estimating Plant-Available Nitrogen Release from Manures, Composts, and Specialty Products (Request pdf e-copy). Gale, E.S., D.M. Sullivan, C.G. Cogger, A.I. Bary, D.D. Hemphill, and E.A. Myhre. 2006. J. Environ. Qual. 35:2321-2332.

♣ Manure on Your Farm: Asset or Liability (PDF-Online). Cogger, C.G. 2004. LPES Small Farms Fact Sheet.

♣ Post Harvest Soil Nitrate Testing for Manured Cropping Systems West of the Cascades (PDF-Online).  Sullivan, D.M. and C.G. Cogger. 2003.EM8832-E. Oregon State University Extension Service.

♣ Supercow: A Liquid Manure Applicator for Small Plot Research (HTML-Online). Bary, A.I., D.M. Sullivan, S.C. Fransen, and C.G. Cogger. 2001. Agronomy J. 93:1344-1345.

♣ Whole-Farm Nutrient Flow and Manure Management (PDF-Online). Cogger, C.G., T.N. Cramer, A.I. Bary, and D.C. Grusenmeyer. 1998.p. 581-586. In Animal Production Systems and the Environment. Des Moines, IA, 19-22 July, 1998.

♣ Sweet Corn (Western Oregon) Nutrient Management Guide (PDF-Online).  Hart, J.M., D.M. Sullivan, J.R. Myers, and R.E. Peachey. 2010.  EM9010-E. Oregon State University Extension Service

♣ Date, Rate, & Place: The Field Book for Dairy Manure Applicators (PDF-Online).  Bary, A.I. and J. Harrison. 2017. PNW 506. Pacific Northwest Extension Publication.

♣ Which Test is Best? Customizing Dairy Manure Nutrient Testing (PDF-Online). Sullivan, D.M., C.G. Cogger, and A.I. Bary. 1997. PNW 505. Pacific Northwest Extension Publication.

♣ Timing of Dairy Manure Applications to Perennial Grass on Well-Drained and Poorly-Drained Soils (Request pdf e-copy). Sullivan, D.M., C.G. Cogger, A.I. Bary, and S.C. Fransen. 2000. J. Soil & Water Conservation. J. Soil and Water Conservation 55:147-152.

♣ Biosolids and Dairy Manure as Nitrogen Sources for Prairiegrass on a Poorly Drained Soil (Request pdf e-copy). Sullivan, D.M., S.C. Fransen, C.G. Cogger, and A.I. Bary. 1997. J. Prod. Agric. 10:589-596.

Organic Farming Research Photo Gallery

Organic Farming Systems Research Photo Gallery

Photo of manure spreader spreading compost.
Above-manure spreader spreading compost.
Photo of winter cereal rye vetch mix as a cover crop.
Above-Winter cereal rye vetch mix as a cover crop.
Photo of Undercutter that skims just under the surface to cut weed roots while minimally disturbing the soil.
Above-Undercutter skims just under the surface to cut weed roots while minimally disturbing the soil.

 

Photo of spader which is gentler on the soil than rototillers.
Above-spader which is gentler on the soil than rototillers and usually both tills and prepares the seed bed for planting in one pass.
Photo of vetch as a winter cover crop in a former corn planting.
Above-vetch interplanted in a former corn planting as a winter cover crop to protect the soil from erosion and provide nitrogen for a spring or summer crop.
Photo of Allis G tractor and weed basket, weeding row vegetable crop.
Above-Allis G tractor with weed basket, weeding row vegetable crop.
Photo of two Roller/Crimpers, front mounted on tractor to crimp cover crops stems to terminate them while leaving them in place to provide a mulch.
Above-Roller/Crimpers-Front mounted on tractor to crimp cover crops stems to terminate them while leaving them in place to provide a mulch. Two different widths shown.

 

Photo of buckwheat as a short term summer cover crop.
Above-buckwheat as a short term summer cover crop.
Photo of mowing down sudangrass, a summer cover crop.
Above-Sudangrass summer covercrop being flailed.

 

Photo of custom strip tiller unit. Front discs cut cover crop, back unit (see insert photo) is a one blade wide Maschio rototiller that cuts a narrow path for planting crops in while leaving the rest of the soil undisturbed.
Above-Custom strip tiller unit. Front discs cut cover crop, back unit (see insert photo) is a one blade wide Maschio rototiller that cuts a narrow path for planting crops in while leaving the rest of the soil undisturbed.

Events and New

Events

 

Compost Facility Operator Training, October

Training and certification for Compost Facility Operators, Managers, and officials involved with Composting. Hands on composting, field trips, examination.

Group of people, long compost pile
Compost Operator Training participants work on a pile.
Small group of people, tractor and trommel separator
Compost Operator Training trommel demonstration.

Compost

Compost and Nutrient Management

Overview:

Composting stabilizes organic wastes, reducing nutrient availability, allowing their use at high application rates as a soil amendment. Composts do affect available nutrient levels in soil, often causing short term immobilization (tie-up) of nitrogen, but a long term slow release. We have evaluated effects of compost applications on nitrogen availability and soil properties.

♣ Compost Operators Training at WSU Puyallup: Training and certification for Compost Facility Operators, Managers, and officials involved with Composting. Hands on composting, field trips, exam.

♣ Yard Trimmings. Yard trimmings are organic materials such as lawn clippings, leaves, and pruned material that is applied, without any processing, directly to soil to be amended.

♣ Compost Analysis. How to sample and prepare your compost to send to a laboratory for analysis, how to choose a laboratory, how to decipher laboratory results.

♣ Food Waste Compost Earthtub Composting Project. Small on-site composter used to compost school lunch program food waste as well as educate students.

♣ Calculating Compost Bulk Density. How to calculate bulk density of composts and compost- type materials such as manures and yard waste.

♣ Clopyralid in Compost.  Facts and background about the Clopyralid contamination problem.

♣ Compost Mixture Calculator. The Compost Mix Calculator version 2.1 is an Excel xls spreadsheet (for computers) or an Online App (for tablets or phones) that calculates compost mixture C:N ratio and moisture content, based on the analysis of your feed stocks and the mixture proportions that you choose. You can use the spreadsheet or App to evaluate the effects of different feedstock mixtures on C:N ratio and moisture content of the initial pile.  The Excel file version also calculates material bulk density and free air space.

Links:

♣ Oregon State University Department of Crop & Soil Science, compost resources.

♣ Washington State Department of Ecology, Composting, Siting and Operating Compost Facilities in Washington State publication, & other publications and resources.

♣ Washington Organic Recycling Council, information, training, events.

♣ The Art and Science of Composting, (pdf) Univ. Wisconsin-Madison

♣ Cornell Composting, educational materials, programs, links.

Photo of small compost bins.

Photo of Earth Tub composting bin.

Photo of large scale aerated compost pile.

Photo of tractor mixing compost.

Extension Publications:

 

♣ Interpreting Compost Analyses (PDF/HTML-Online), Sullivan, D.M., A.I. Bary, R.O. Miller, and L.J. Brewer. 2018. Oregon State University Extension Bulletin EM9217.  Compost can return nutrients and organic matter to the soil, a proven practice for soil health enhancement. This publication focuses on selecting a lab to perform compost analyses, determining which compost analyses are most relevant to your needs, assessing whether compost is sufficiently stabilized, and avoiding over application of composts high in soluble salts or composts with a pH unsuited to your crop.

♣ Backyard Composting (PDF-Online), Cogger, G., D.M. Sullivan, A. Bary. 2017. Washington State University Extension Bulletin EB1784E.

♣ Washington State Compost Educator’s Guide (Request pdf e-copy), Wescott, H., A. Bary, C. Cogger, C. Sullivan, and A Mack. Washington St. Univ. The purpose of the guide is to: provide consistent, science-based information about residential composting and vermicomposting for use in Washington State, assist compost educators in creating training events such as workshops, and inspire a clear vision for home composting as a cornerstone of sustainable living.

Research Publications:

♣ Urban Highway Roadside Soils and Shrub Plantings are Enhanced by Surface Applied and Incorporated Organic Amendments (Request pdf e-copy). Bary. A. R.L. Hummel, and C. Cogger. 2016. J. Arbor. Urban Hort. 42:418-427.

♣ Fate of Antibiotics and Antibiotic Resistance During Digestion and Composting: A Review (Request pdf e-copy). Youngquist, C.P, S.M. Mitchell, and C.G. Cogger. 2016. J. Environ. Qual. 45:537-545. doi:10.2134/jeq2015.05.0256

♣ Antibiotic Degradation During Thermophilic Composting (Request pdf e-copy). Mitchell, S.M., J.L. Ullman, A. Bary, C.G. Cogger, A.L. Teel, and R.J. Watts.  2015. Water Air Soil Pollut. 226:13.

♣ Soil and Redosier Dogwood Response to Incorporated and Surface-Applied Compost (Request pdf e-copy). Cogger, C., R. Hummel, J. Hart, and A. Bary. 2008. Hortsci. 43:2143–2150.

♣ Comparison of a Gas Detection Tubes Test with the Traditional Alkaline Trap Method to Evaluate Compost Stability (Request pdf e-copy). Benito, M, A. Masaguar, A. Moliner, C.G. Cogger, and A.I. Bary. 2005. Biol. Fertil. Soils 41:447-450.

♣ Potential Compost Benefits for Restoration of Soils Disturbed by Urban Development (Request pdf e-copy). Cogger, C.G. 2005. Compost Sci. Utiliz. 13:243-251.

♣ Nitrogen Availability Seven Years After a High-Rate Food Waste Compost Application (Request pdf e-copy). Sullivan, D.M., A.I. Bary, T.J. Nartea, E.A. Myhre, C.G. Cogger, and S.C. Fransen. 2003. Compost Sci. Util. 11:265-275.

♣ Food Waste Compost Effects on Fertilizer Nitrogen Efficiency, Available Nitrogen, and Tall Fescue Yield (Request pdf e-copy). Sullivan, D.M., A.I. Bary, D.R. Thomas, S.C. Fransen, and C.G. Cogger. 2002. Soil Sci. Soc. Am. J. 66:154-161.

♣ Fertilizer Nitrogen Replacement Value of Food Residuals Composted with Yard Trimmings, Paper, or Wood Wastes (Request pdf e-copy). Sullivan, D.M., S.C. Fransen, A.I. Bary, and C.G. Cogger. 1998. Compost Sci. 6(1):6-18.

♣ Slow-Release Nitrogen From Composts: The Bulking Agent is More Than Just Fluff (Online abstract with pdf chapter or ebook available for purchase). Sullivan, D.M., S.C. Fransen, A.I. Bary, and C.G. Cogger. 1998. p. 319-325. In: S.L. Brown, J.S. Angle, and L.W. Jacobs (ed.) Beneficial co-utilization of agricultural, municipal, and industrial by-products. Kluwer Academic Publishers, Dodrecht, The Netherlands. [book chapter]

Photo of covered compost pile.

Supercow: Liquid Manure Applicator


Supercow: A Liquid Manure Applicator for Small Plot Research

A.I. Bary, D.M. Sullivan, S.C. Fransen, and C.G. Cogger
2001. Agronomy J. 93:1344-1345.
(♣ PDF of full article-Online)

Small-plot research in manure nutrient management requires accurate manure applicators that are easy to operate and maneuver. Our objective was to design a small-plot liquid manure applicator that could apply variable rates of dairy manure containing up to 60 g kg-1 solids to perennial grass plots while avoiding traffic and compaction on the plots. The applicator consists of a 1000-L fiberglass agitation tank mounted on four load cells, a delivery pump and motor, and a side-mounted boom with four nozzles for manure application, all built onto a wagon and towed by a tractor. The side-mounted boom allows manure application without traffic on the plots. Manure application typically was within 7% of the target rate and had a coefficient of variation ranging from 2 to 17%, measured over a series of rates from 53 to 211 MG ha-1 (wet weight). The precision, accuracy, and ease of operation of the liquid manure applicator met our research requirements. Efficiency of operation could be improved using a larger agitation tank.

Supercow Liquid Manure Applicator spraying forage research plots with manure.
Above, Supercow Liquid Manure Applicator spraying forage research plots with manure.
Supercow Liquid Manure Applicator spraying research forage plots.
Above, closeup of Supercow Liquid Manure Applicator spraying research forage plots.
Freshly applied manure by Supercow Liquid Manure Applicator.
Above, freshly applied manure by Supercow Liquid Manure Applicator.