Minimising nitrogen losses to improve use efficiency in summer crops

Abstract

As reliance on N fertilizer increases, getting good crop recovery of applied N is essential. Crop N recovery is most efficient when N is distributed through the root volume.
Gaseous losses of fertilizer N can be substantial, with denitrification of greatest concern for summer sorghum.
Ensuring fertilizer N is in the crop or deeper in the soil profile is the best defence against loss. Controlled release fertilizers can reduce denitrification but are rarely economic; legume N is effective