Effect of nitrogen doses and grass crop residue on common bean in no-tillage / Effect of nitrogen doses and grass crop residue on common bean in no-tillage

Abstract

Nitrogen (N) is the most absorbed nutrient by the common bean, and the availability of this element changes according to the crop residues present on the soil surface. The aim of this study was to assess the effect of top-dressed doses of N and crop residue (maize alone, maize intercropped with brachiaria and brachiaria alone) on the performance of irrigated common bean. The experiment was conducted in a split-plot arrangement, where the plots consisted of residues of maize crop alone, maize intercropped with brachiaria, and brachiaria alone and the subplots consisted of doses of top-dressed N applied to common bean (0, 40, 80, 120, and 160 kg ha-1). Brachiaria alone and maize intercropped with brachiaria provided full coverage of the soil surface. The C/N ratio in the maize crop residue was higher than that in the brachiaria crop residue. This result characterizes maize as a material with slower and more gradual decomposition compared to brachiaria, which had a higher N content because it was desiccated at the time of its full vegetative vigor. Crop residue affected grain yield, particularly the cultivation on brachiaria alone. The maximum grain yield was achieved at an estimated dose of 136 kg ha-1 of N. These results demonstrate the effect of crop succession and nitrogen fertilization on the common bean agronomic performance in the no-tillage system, helping farmers and technicians in decision making.