Biologically Based Fertilizer Recommendations to Meet Yield Expectations and Preserve Water Quality

This is a multi-state project, lead by A. Franzluebbers from USDA-ARS, that seeks to test and model improved methods to develop N fertilizer recommendations for corn in several states of the mid-Atlantic Region, including Pennsylvania. The foundation of the project is a newly developed soil test based on the "flush of CO₂"method, which can putatively predict N supply with higher accuracy than previous tests. This would enable better accounting of N sourcing by the soil and fine tuning N recommendations. The benefits include the ability to realize the yield potential of a site, reduced fertilizer use, lower production costs, and reduced potential water pollution with nitrogen. Cover crops experiments in PA from the C. White and J. Kaye Cover Crop Cocktail experiments are included in the network of trials. We are also interested in linking the predicted nitrogen quantities of the test with those predicted by the model Cycles in order to have a cohesive theoretical and empirical framework to use and interpret N cycling in soils.