Influence of nitrogen management on sweet corn growth, canned yield, and soil properties under various irrigation regimes and tillage systems

Optimal nutrient supply, either chemical or biological fertilizers, can be customized for water availability and paired with correct tillage systems. This approach is necessary to ensure high production in corn (Zea mays L.). To determine possible impacts of nitrogen (N), various irrigation regimes and tillage systems were evaluated on sweet corn (Zea mays L. var Saccharata). Dependent variables were plant growth, yield, water use efficiency (WUE), and soil characteristics. For this purpose, a two-year experiment (۲۰۱۶-۲۰۱۷) was conducted in a split-factorial design, involving randomized complete blocks with three replications at the Agricultural Experimental Station, School of Agriculture, Shiraz University, Shiraz, Iran. The treatments were two tillage systems [conventional (CT) and decreased (RT)] as the main plot. Five N rates were used (۰, nitroxin, ۱۵۰ kg N ha-۱, nitroxin + ۱۵۰ kg N ha-۱, and ۳۰۰ kg N ha-۱). The two irrigation regimes were [۱۰۰% (normal) and ۷۵% of plant water need (PWR)(Kc)] as subplots, respectively. Also, five N rates and sources (۰, nitroxin, ۱۵۰ kg N ha-۱, nitroxin + ۱۵۰ kg N ha-۱, and ۳۰۰ kg N ha-۱) were used in combination with two irrigation regimes [۱۰۰% (normal) and ۷۵% of plant water requirement (PWR)(Kc)]. The findings provided an indication that the canned yield and WUE could be raised by applying ۳۰۰ kg N ha-۱, ۷۵% of PWR, and the CT system. The highest soil N content occurred in RT systems applied with nitroxin + ۱۵۰ kg N ha-۱ and ۷۵% of PWR in the first year and under CT systems by applying nitroxin + ۱۵۰ kg N ha-۱ and the normal irrigation in the second year. Nevertheless, the maximum soil OC content occurred in the RT system applied with nitroxin + ۱۵۰ kg N ha-۱. To conclude, nitroxin-inoculated sweet corn responded favorably to the RT system with sufficient N rate and irrigation regimes down to ۷۵% of PWR. Moreover, reducing irrigation water volume exerted no notable impact on reducing canned yield while it conserved water more significantly.

Keywords:

Conservation tillage , harvest index , Irrigation volume , nitroxin inoculated plants , Water use efficiency