Farmers develop nutrient management plans to better manage their fertilizer dollars. Increasingly nutrient management plans are required for federal, state, and county government programs. These programs require plans that are written using Wisconsin Nutrient Management Standard 590 guidelines. The Standard requires routine soil testing at least once every four years. Soil testing provides the foundation of sound nutrient management plans.

The Natural Resource Conservation Service Code 590 references UW-Extension A2100, “Sampling Soils for Testing,” as the soil sampling guide for Wisconsin. This publication provides guidelines for soil sampling for both conventional fertilizer recommendations and for site-specific management for variable rate fertilizer applications. The method of fertilizer application determines the soil sampling procedure.