Managing Poultry Manure Using the Pre-Sidedress Soil Nitrate Test

Introduction The pre-sidedress nitrate test (PSNT) was originally developed for the humid Eastern U.S. to help producers decide, in season, when it was necessary to apply additional N to obtain optimum corn yields. Once a critical PSNT level for optimum yield has been established for a specific crop, the PSNT allows producers to make a more confident decision on whether or not to sidedress with additional N, avoiding unnecessary fertilizer costs or yield loss due to insufficient N. More recently, the PSNT has been revised for use in Colorado on non-manured fields (Bauder et al., 2003).