Soil Health & Cover Crops

Understanding and Measuring Organic Matter in Soil: Understanding organic matter’s role in soil can be critical to any agricultural operation: learn the emerging methods of measurement in this publication.

Interpreting Compost Analyses: Compost can return nutrients and organic matter to the soil, a proven practice for soil health enhancement. It can improve crop growth and provide environmental benefits by improving soil tilth and the soil’s capacity to absorb and hold water and plant nutrients. 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 overapplication of composts high in soluble salts or composts with a pH unsuited to your crop.

Soil Organic Matter as a Soil Health Indicator: Sampling, Testing and Interpretation: Testing for soil organic matter helps you monitor soil health over time. Good soil management practices can improve soil organic matter in three to five years.

Agricultural Composting and Water Quality: This publication addresses factors that farmers must consider when planning an on-farm composting enterprise: the composting process and its impact on water quality, site selection, facility layout and design, composting methods, and managing water and leachate. The content pertains to small and medium-size on-farm composting enterprises that handle about 100 to 5,000 tons of raw organic material per year.


Manure Application Rates for Forage Production: Explains step-by-step how to estimate the amount of manure to apply for forage production, using application rates based on soil tests and growing conditions in western Oregon. Provides examples of estimating manure amounts for perennial crops and annual crops. Describes how to check application rates for silage corn using the pre-sidedress soil nitrate test (PSNT), interpret P and K soil tests, and use an end-of-season soil test for nitrate nitrogen to adjust next season's manure application rates. Includes tables, figures, and additional sources of information.

Nutrient Management

OSU Organic Fertilizer and Cover Crop Calculator: This free online tool compares the nutrient value and cost of cover crops, organic and synthetic fertilizers and compost. Use this Calculator to develop well balanced and cost effective nutrient management programs for your farm.

OSU Organic Fertilizer & Cover Crop Calculator: Predicting Plant-available Nitrogen: Describes the OSU Organic Fertilizer & Cover Crop Calculator and using it to predict plant-available nitrogen.

Nutrient Management for Sustainable Vegetable Cropping Systems in Western Oregon: This publication reflects over 30 years of vegetable production research conducted in the Willamette Valley. It is divided into three main sections: sustainable soil health; soil testing and nutrient management; and nitrogen management. The appendix includes detailed information on the technical aspects of fertilizer technology.

Soil Nitrate Testing for Willamette Valley Vegetable Production: A soil nitrate test measures the concentration of nitrate in the soil at a specific moment in time, including nitrate originating from organic inputs, fertilizer, and soil organic matter. This publication describes how to use in-season soil nitrate testing to adjust sidedress N fertilizer application rate to match crop N requirements.

Estimating Plant-Available Nitrogen Release from Cover Crops: This publication assists western Oregon farmers and agricultural professionals in determining the nitrogen fertilizer replacement value of winter cover crops. Includes information on plant-available nitrogen (PAN) basics; a site-specific, step-by-step method to estimate PAN; Willamette Valley case studies; and appendices summarizing Willamette Valley cover crop research that supports these PAN estimates.

A Guide to Collecting Soil Samples for Farms and Gardens: Laboratory soil tests help you develop your soil and increase crop production by providing information on available nutrient content. Soil testing helps you select the correct kind and amount of fertilizer and liming material. Learn why, when, and where to collect your soil sample, and get straightforward instructions for how to take the soil sample and choose a lab to perform the analysis.

Soil Testing: A Guide for Farms with Diverse Vegetable Crops: This fact sheet presents a comprehensive, yet affordable, procedure for implementing an annual soil-testing program for farms with diverse vegetable crops.

Soil Fertility in Organic Systems: A Guide for Gardeners and Small Acreage Farmers: This publication discusses the many types of fertilizers and soil amendments available for organic plant production. Fertilizer formulations, nutrient availability, and application practices for common organic products are also explained. While the primary focus is on building and maintaining fertile soil, information about how to protect soil and water resources in this context is included. View on WSU site:

Applying Lime to Raise Soil pH for Crop Production (Western Oregon): This publication describes how to estimate lime application rate and lists criteria for choosing liming materials (source), lime application method (placement), and how often to apply lime (frequency).

Baseline Soil Nitrogen Mineralization: Measurement and Interpretation: Baseline N mineralization refers to plant-available nitrogen release that accompanies the decomposition of soil organic matter. The rate of baseline soil N mineralization is governed by the quantity and quality of soil organic matter, as modified by soil moisture and temperature. Baseline soil N mineralization typically supplies about half of crop N uptake. Soils that have been heavily manured for many years or are naturally very high in soil organic matter can supply most of the N required for crop production. Several laboratory tests for N mineralization are available, but most are useful only as measures of relative changes in soil health, not for adjusting N fertilizer rates.

Nutrient and Soil Health Management for Sweet Corn (Western Oregon): This guide integrates recommendations for nutrient management with cover cropping practices that promote soil health. Recommendations for nutrient rate, source, timing and placement for nitrogen, phosphorus, potassium, sulfur, calcium, magnesium and zinc are provided for organic and conventional cropping systems. Cover cropping practices that reduce soil erosion and conserve nutrients are highlighted.

Fertilizing with Manure and Other Organic Amendments: Are you thinking about using manure to fertilize your farm but want more information? Properly managed manure applications recycle nutrients to crops, improve soil quality, and protect water quality. From deciding whether manure is right for your farm to learning how to calibrate manure applications, this publication takes you through the process of fertilizing with manure and other organic amendments.