Nitrogen Responsiveness of Maize Hybrids Under Dryland Conditions

Nitrogen (N) plays a decisive role in the growth and yield of crops. Hence, a high maize grain yield depends upon substantial N inputs. In the present study, morphological traits and yield components, grain yield, rain use efficiency (RUE), and N partial factor productivity (NPFP) were analyzed in two maize hybrids (ZP666 and NS6030) for 2 yr using four N rates (0 (N0), 60 (N60), 120 (N120), and 180 (N180) kg N ha−1). In a climatically more favorable year (2022), the studied traits and NPFP were higher, while RUE was lower. Hybrid ZP666 had higher values of morphological traits and yield component traits, except 1000-grain weight, grain yield, RUE, and NPFP, than hybrid NS6030. The highest values for morphological traits, yield components, grain yield (9383 and 9456 kg ha−1), and RUE (27.1 and 27.2 kg ha−1 mm−1) were obtained at 120 and 180 kg N ha−1. The NPFP decreased significantly with increasing N input, from 137.6 (control) to 52.5 kg grain per kg fertilizer N (180 kg N ha−1). A suitable hybrid selection and the application of a moderate N fertilizer rate of 120 kg N ha−1 could contribute to high yields and lower nitrogen losses to the environment and promote sustainable agriculture.