Study the Affect of Cover Crops on Soil Health and N Fertilizer Response

a) Project title: ‘Quantifying the N Benefit of Cover Crop Use’ b) Primary area for consideration: This conservation project will demonstrate the environmental soundness of cover crops for environmental protection and natural resource enhancement and show that using cover crops for soil protection and soil enhancement may require modifying crop N fertilizer recommendations, resulting in greater fertilizer N use efficiency. The benefits of using cover crops to minimize soil erosion are well known. Likewise, there is increasing knowledge that using cover crops builds soil carbon, improves soil structure, and increases soil biological diversity, each of which has indirect effects on enhanced plant performance. Previous research with cover crops at the University of Kentucky demonstrated the benefits of cover crops for scavenging mineralizable soil N produced over winter. What is less appreciated is the extent to which preserving residual soil N can contribute to the nutrition of subsequent crops and how that preserved N would influence subsequent recommended fertilizer N rates. Preserving residual soil N may allow fertilizer N rates to be reduced (to an undetermined extent) for the following crop. However, that reduction may also influence available N in following years, thereby affecting future fertilizer N management decisions. Consequently, integrating cover crops into crop rotation systems, from the perspective of fertilizer N rate management, needs to be demonstrated.