Using Soil Organic Matter to Help Make Fertilizer and Pesticide Recommendations

Abstract

Soil organic matter (SOM) influences the physical and chemical properties of soils. To gain information on the use of SOM content in determining nutrient and pesticide recommendations for crop production, a survey was sent to commercial and university soil testing laboratories across the USA. Laboratories that analyze for SOM use the value in different ways. Some of these ways are: soil categories for making lime recommendations, nitrogen (N) recommendations for various crops, and S recommendations. SOM content is determined routinely by university soil testing laboratories in Nebraska, Colorado, Missouri, and Wisconsin. The University of Minnesota's Department of Agronomy uses either residual NO3–N in the 0- to 60-cm depth or SOM to make fertilizer N recommendations for grain crops. Wisconsin and Missouri use SOM to make fertilizer N recommendations for a wide range of grain, vegetable, and oil crops. All laboratories reported that their herbicide recommendations follow label suggestions.