University of Arkansas, Fayetteville Division of Agriculture


Nitrogen fertilizers


Leguminous cover crops have the potential to combat the rising input cost of commercial nitrogen (N) fertilizers. This experiment examines benefits of implementing a leguminous cover and/or companion crop into a corn production system. Legumes biologically fix nitrogen from the atmosphere, adding to the nitrogen content of the soil. In this experiment Austrian winter peas (Pisum arvense) (AWP) were used as the leguminous cover crop and cowpeas (Vigna unguiculata) were used as the companion crop. A two year experiment was carried out in which winter peas were planted on half the field in the fall and allowed to grow until late April to early May. The pea biomass was recorded, then the peas were plowed into the soil allowed to incorporate and begin decomposition, followed by corn planting. Different rates of commercial nitrogen were applied and varying seeding rates of companion-crop peas were also evaluated. Nitrogen was applied at 0, 112, and 224 kg ha-1. Companion-crop peas were planted at 0, 4, and 8 plants m-1. The corn was harvested, and yield as influenced by the various treatments, was evaluated. In both years, cover-crop peas provided all or a significant amount of corn N needs. This has useful implications for producer profitability and the environment since commercial N requires fossil fuels during its production.