The leaching of nitrate to groundwater and the increasing occurrence of groundwater with excessive nitrate levels for human consumption is a major concern in Nebraska. The amount of leached NO3- depends on soil NO3- concentration at different soil depth layers and the quantity of water movement downward through these soil layers to beyond the root zone.
Fall fertilizer applications offer cost savings and time management benefits, but also may contribute to increased soil nitrate-N leaching. With Nebraska's high soil moisture levels, consider these suggestions when applying nitrogen this fall.
Iowa State University researchers concluded from a long-term field study that poultry manure, when applied at a rate to meet crop nitrogen (N) requirements, can reduce nitrate loss and achieve equal or better yields in corn-soybean production systems.
A fall nitrogen application has a relatively high loss potential and is considered the riskiest N management practice. Consider breaking tradition and splitting your N applications next year to coincide with when your corn most needs more N.
This project will demonstrate how subsoil injection of an abundant carbon source (recycled sawdust and wood shavings) will establish a biologically active layer for interception and removal of dissolved nitrate after it has left the crop root zone.