Agronomic and economic evaluation of various furrow irrigation strategies for corn production under limited water supply

It is commonly known that furrow irrigation is a less efficient method of irrigation than a sprinkler center pivot system, but many fields' irregular shapes prevent the use of center pivot irrigation. Restricted water allocations of surface and subsurface water are forcing farmers to implement irrigation strategies that will reduce water application on furrow-irrigated fields. The study site was located in south central Nebraska. The objective of this study was to evaluate two irrigation scheduling scenarios: (1) the every-furrow irrigation method with 50% (0.5), 70% (0.7), and 90% (0.9) field capacity (FC) treatments and (2) the every-furrow (EF) irrigation method compared to the every-other-furrow (EOF) method with both using the 75% field capacity (0.75 PC) treatment effects on corn (Zen mays L.) yield, net economic return, and residual soil nitrate-nitrogen. The experimental design was a randomized complete block with three replications. Grain yield showed no significant difference in both years for all irrigation treatments. Irrigation water application with the 0.5 FC strategy reduced the amount of applied water by approximately 70% and 200% compared to 0.7 FC and 0.9 FC, respectively, in both years. The water savings with the EOF method over the EF method was 23%. The economic return with 0.5 FC was 6% to 13% and 36% to 69% over 0.7 and 0.9 PC irrigation treatments, respectively. The 0.5 PC strategy showed no significant reduction in nitrate-nitrogen loss over 0.7 FC and 0.9 PC, while the EOF method reduced soil nitrate-nitrogen loss by 11% to 26% over the EF irrigation method in both years. The average economic return over two years with the 0.5 PC strategy was 9.5% and 52.5% over 0.7 FC and 0.9 PC irrigation treatments, respectively, while the average economic return with the EOF method over the EF method was 9.5%. Findings demonstrated that economic and environmental benefits of using 0.5 PC or the EOF method is much superior to other furrow irrigation strategies, especially in areas with limited water resources where less efficient irrigation methods may lead to significant water loss.