In silico assessment of sowing dates and nitrogen management in common bean crops

Abstract

The application of nitrogen soil fertilization is one of the factors that leads to high yields in common bean crops. Therefore, the aim of this work is to evaluate in silico the effects of nitrogen rates and topdressing dates on common bean yield in three different sowing dates and three growing seasons in Goiás State, Brazil. The CSM-CROPGRO-DRYBEAN crop model was parameterized, validated, and applied to simulate common bean yields in wet (Nov to Dec), dry (Jan to Feb), and winter (May to Jun) seasons for nitrogen rates applied at sowing and as topdressing. An economic analysis was carried out to assess the viability of each scenario. Nitrogen rate was the most important factor in the wet season in obtaining high yields. Yields increased as nitrogen rates increased. In the dry season, sowing date was the most important factor in obtaining the highest yields. However, this season presented the lowest increase in yield per kg of nitrogen, whereas the winter season presented the highest increase. In the winter season, nitrogen rate was also the most important factor in obtaining high yields, and sowing date and topdressing had a low effect on yield. The highest crop economic return was obtained with N rates (sowing/topdressing) of 60/180 kg ha−1 and 40/120 kg ha−1 for the wet and winter seasons, respectively. The bean price was fixed at US$ 0.85 kg1. Therefore, the best management strategy is an early sowing date for the dry season, high nitrogen rates and an early sowing date for the wet season, and high nitrogen rates for the winter season.