Nitrogen Rate and Hybrid Selection Matters Productivity of Maize–Maize Cropping System under Irrigated Arid Environment of Southern Punjab, Pakistan

Abstract

Maize is sown during spring and autumn seasons in Pakistan; however, studies on inter-seasonal variability on maize productivity, agronomic and nitrogen use efficiencies (NUEs) are limited. Therefore optimization of nitrogen (N) rate and hybrids selection for each season is critical to harvest better yield in maize–maize cropping system. Two independent field experiments were conducted to optimize N rates for different hybrids to improve maize productivity and NUEs in spring and autumn seasons during 2016 and 2017. During spring season, three spring-hybrids (P-33M15, M-DK6525 and S-NK8441) and during autumn season, three autumn-hybrids (P-30R50, M-DK6714 and S-NK6621) were sown under five N levels i.e., 0, 80, 160, 240 and 320 kg ha−1. Maize yield and related traits, and NUEs were improved with each higher level of N application. Highest and lowest grain yield, agronomic and economic NUEs were recorded at 320 kg N ha−1 and without N application, respectively in both seasons. Likewise, highest grain yield and NUEs were observed by spring-hybrid P-33M15 and autumn-hybrid P-30R50, while lowest were obtained by spring hybrid S-NK8441 and autumn hybrid S-NK6621 during both years. Nonetheless, maximum net income and benefit: cost ratio was observed by spring-hybrid P-33M15 and autumn-hybrid P-30R50 at higher N level (320 kg ha−1) and maize cultivation without N was not profitable in both seasons. Maize cultivation with N application at 320 kg ha−1 seemed a viable option to get maximum productivity, economic returns and NUEs of maize–maize cropping system in irrigated arid environment of southern Punjab, Pakistan and might be for other areas having similar environmental conditions.