Improving the Synchrony of Hairy Vetch (Vicia villosa) Nitrogen Release for Corn (Zea mays) Growth.
Justine Cook1, Robert Gallagher1, Jason Kaye1, Jonathan Lynch2, Anna Starovoytov1, and Wendy McCoy1. (1) The Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802, (2) The Department of Horticulture, Pennsylvania State University, 221 Tyson Building, University Park, PA 16802
Green manure legume crops can often meet much of the nitrogen (N) demand of a crop. There may be, however, an asynchrony between N mineralization from green manures and crop N uptake, resulting in substantial nitrogen loss through leaching or denitrification. In our research, we hypothesize that the synchrony between N mineralization and crop N uptake can be improved by manipulating the termination date of the hairy vetch (Vicia villosa) and the sowing date of the corn (Zea mays) in the spring. This will regulate the quality and quantity of the N in the vetch, the rate of N mineralization from the vetch residues, and the relative rate of N uptake in the corn. Field experiments have been implemented that will evaluate three vetch termination dates on soil N availability and corn N uptake. In addition, the effects of the C/N ratio of the hairy vetch residues on N uptake by the corn will also be considered. We anticipate that these experiments will provide help provide management guidelines to improve the N-use efficiency of green manure systems and reduce nitrogen pollution.