Productivity and profitability of maize as affected by nitrogen sources and rates

Abstract

The use of nitrogen (N) sources that reduce N losses may be an interesting management strategy to increase the economic and environmental sustainability of maize crops. This study aimed to assess the effects of different N sources and rates on maize grain yield and crop profitability. The experiment was conducted in the field on a Red Nitisol of clay texture during two growing seasons. The experimental design was a randomized block with split plots. Four sources of N were applied to the main plots: conventional urea, protected urea, urea treated with nitrification inhibitor, and urea treated with urease inhibitor. Split plots were treated with four N rates: 0, 140, 280, or 420 kg N ha−1. The four N fertilizer sources produced no differences in grain yield, which ranged from 3.2 to 15.9 Mg ha−1. This parameter showed a quadratic response to increasing N rates, regardless of N source. Theoretical N rates for optimal grain yield were estimated at 407 and 411 kg N ha−1 in 2016/2017 and 2017/2018, respectively. The highest profitability indices were obtained by applying 378 kg N ha−1 from conventional urea in 2016/2017 and 278 kg N ha−1 from urea treated with urease inhibitor in 2017/2018.

Maize-ruzigrass intercropping, nitrogen fertilization and plant density improve the performance of soybean grown in succession

“…Recently, farmers have reduced N fertilization of secondcrop maize (Sapucay et al, 2020) because of the high agrometeorological risk (Nóia Júnior & Sentelhas, 2020), the small response of the crop to N in this growing season (Sapucay et al, 2020), and the high cost of N fertilizers (Mergener et al, 2022). However, this management strategy may be detrimental to crop yields.…”