Fate of Manure Nitrogen Applied for Grass Silage Production

Purpose

Previous research conducted in western Washington State has demonstrated that when manure N is applied at rates greater than needed for grass uptake, excess N in soil in the form of nitrate-N can leach to shallow groundwater during the months of high rainfall. In a prior study, it was evident that tillage and reseeding of the cropland was a contributor to loss of nitrate–N from soil to underlying groundwater.…