Abstract

            The inclusion of cover crops into a spring applied nitrogen system has been a proven method used to improve nitrogen efficiency, while maintaining crop yields. However, minimal research has been done on the inclusion of cover crops into a fall applied system. Due to the large quantity of producers continuing to fall apply their nitrogen source, this necessitates the objectives of this research: to investigate I) the combined impact of nitrogen rate, timing, and cover crop inclusion on nitrogen use efficiency II) determine the effect of cover crops on the optimum nitrogen rate for corn production III) calculate the nitrogen retention of the cover crops to estimate possible environmental benefits. The experimental site will be located at the Illinois State University farm in Lexington, IL.  The treatments (independent variables) that will be analyzed consist of the nitrogen application rates (200 kg ha-1, 145 kg ha-1, 90 kg ha-1, a control receiving 200 kg ha-1 and a zero control with no added fertilizer) and the addition of the cover crop treatments (tillage radish (Raphanus sativus L.), cereal rye (Secale cereal L.), crimson clover (Trifolium incarnatum), tillage radish/ crimson clover blend and tillage radish/ cereal rye blend). The variation in treatments will be used to determine the effects that they have on grain yield and mineralization rates (dependent variables).  The results from this study will indicate the effectiveness of varying nitrogen rates and cover crop species on nitrogen efficacy and corn yield.

 

Research Objectives

            The objectives of this research are to investigate I) the combined impact of nitrogen rate, timing, and cover crop inclusion on nitrogen use efficiency II) determine the effect of cover crops on the optimum nitrogen rate for corn production III) calculate the nitrogen retention of the cover crops to estimate possible environmental benefits.