Nitrogen levels and rotation with cover crops in wheat under no-tillage

Abstract

The spread of the conservationist agriculture system involving green fertilization, crop rotation, and no-tillage has altered the dynamics of production, which can benefit the development and productivity of the successor crop, as well as the N fertilizer economy. In this context, the objective of this experiment was to study the effect of single maize cropping and maize intercropping with four cover crops in conjunction with the application of N doses under cover on wheat. The experiment was carried out in 2015 and 2017, in an experimental area using a 5 × 4 factorial randomized block experimental design with four replicates. Treatments consisted of the combination of five cover crops (maize, maize + Crotalaria spectabilis, maize + Cajanus cajan, maize + Canavalia ensiformis, and maize + Urochloa ruziziensis) with four N doses (0, 40, 80, and 120 kg ha-1) in no-tillage wheat production. The main production components and yield of wheat were evaluated. It was concluded that the plant residues of maize + Canavalia ensiformis and maize + Urochloa ruziziensis enhanced the yield of wheat cultivated in the winter of 2015 and 2017, when compared with the other treatments. The effect of N doses on wheat grain yield was positive (with significant increase in grain yield) and the maximum average was obtained with the application of 74 and 86 kg ha-1 of N in 2015 and 2017, respectively.