Application of controlled-release nitrogen fertilizer in irrigated common bean crops

The use of adequate management practices and high nitrogen fertilizer rates have contributed to increase the common bean grain yield, however, the application of nitrogen fertilizer at sowing still requires evaluations for irrigated crops in the Brazilian Cerrado biome region. Thus, the objective of this work was to evaluate the effect of application of different rates of controlled-release nitrogen fertilizer—dimethylpyrazole phosphate (DMPP)—at sowing and as top-dressing on agronomic performance and leaf area index of irrigated common bean crops grown in the Brazilian Cerrado biome region. A randomized block design in a 4×3 factorial arrangement with four replications was used. The treatments consisted of four nitrogen rates (0, 60, 120, and 180 kg ha-1) and three application forms (100% at sowing, 100% as top-dressing, and 50% at sowing + 50% as top-dressing). Irrigation was managed with class A tanks and two-day intervals. The nitrogen applied at the different stages of the crop did not affect the production components of the common bean plants. The highest grain yields were found with the nitrogen rates of 180 kg ha-1 in 2015 (1,756.37 kg ha-1), and 123.98 kg ha-1 in 2016 (1,799.63 kg ha-1).