Extension Service Site Publications

• (2021) Updated Lime Requirement Recommendations for Oregon The Oregon State University Soil Fertility Program has completed a formal evaluation of the Sikora buffer to replace the SMP buffer for estimating lime requirement in Oregon. Twenty-four acidic soils from Oregon were tested for actual lime requirement using a lab incubation of lime and soils. The actual amount of lime needed to reach pH targets of 5.6, 6.0, and 6.4 was highly correlated to the SMP buffer (r2 = 0.91-0.93) and the Sikora buffer pH (r2 = 0.91-0.93). These correlations are the basis for new updated lime recommendations for both Sikora and SMP buffer pH methods (Table 1) and will be used to update OSU extension guides containing lime recommendations. The new SMP recommendations are included for the time being for the remaining labs still using the SMP method, but may be phased out over time as more labs switch to Sikora. We thank the Oregon Tall Fescue Commission for providing the necessary support to complete this project.
• (2020) 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.
• (2020) Dairy Manure Applications in Irrigated Wheat Production Systems Discover best management practices for irrigated wheat production systems receiving dairy manure applications. Recommendations are based on field research conducted in southern Idaho. Grain protein concentration, soil organic matter and plant-available organic nitrogen (N) increased significantly with increasing dairy manure application rate and frequency. These outcomes are beneficial for production systems that include hard red wheat varieties in the rotation.
• (2019) 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.
• (2019) Camelina Nutrient Management Guide for the Pacific Northwest Camelina is a drought-tolerant, low-input, oilseed crop grown throughout the U.S. Pacific Northwest. This publication provides soil fertility recommendations—including nitrogen, phosphorus, potassium, sulfur, and soil pH adjustments—for dryland and rainfed camelina production in areas of the Pacific Northwest that receive more than 12 inches of rain per year.
• (2019) Nutrient Management for Pastures: Western Oregon and Western Washington Describes nutrient management practices for pastures to produce forage as a main feed source for western Oregon and Washington livestock.
• (2015) Sampling Dairy Manure and Compost for Nutrient Analysis This guide describes how to obtain a representative sample of stockpiled dairy manure or dairy compost, select a reliable manure or compost testing laboratory, determine which lab analyses are needed (including total nitrogen, nitrate nitrogen, ammonium nitrogen, total phosphorus, total potassium and solids), and estimate nutrient availability. It gives illustrated, step-by-step sampling instructions and equations for converting units from dry weight to as received and vice-versa.
• (2010) Nutrient Management for Field Corn Silage and Grain in the Inland Pacific Northwest Adequate nutrition is essential if productive new corn hybrids are to realize their full yield potential. This publication provides fertilizer guidelines based on university research and a special section on manures as nutrient sources for corn.
• (2022) Fertilizing with Biosolids Biosolids can be used to supply nutrients to crops. The nutrient content and fertilizer replacement value of biosolids and the relationship between biosolids nutrient inputs and crop removal of nutrients are described. Discusses the effects of biosolids processing on nitrogen (N) forms, organic N mineralization rates, and ammonium-N retention and explains how to convert N-availability estimates to application rates. Covers biosolids quality factors (trace element concentrations and pathogen levels), the effects of biosolids applications on soil pH and soil quality, applicable regulations, and questions about biosolids safety and application practices. Includes sources for additional information.