The best management of soil, irrigation, and crop nutrients is among major components of sustainable agriculture that reduces groundwater contamination, prevents soil degradation, and guarantees the best resource use efficiency. Trials were conducted to optimize maize (Zea mays L.) yield by experimenting various irrigation water regimes, nitrogen (N) application rates, and methods in 96 pots under arid environmental conditions during autumn 2012. Crop hydrological and agronomic characteristics were assessed under a completely randomized design with factorial arrangements. Water and N stress to the plants under observation significantly reduced the water potential, osmotic potential, and turgor pressure of the leaves. Crop growth rate and total dry matter production were significantly improved by an increase in N fertilizer application up to 300 kg ha−1 (equivalent to 4.8 g N pot−1) for all water regimes. Grain per cob, 1,000-grain weight, and final grain yield were higher at 100% field capacity with the application of 300 kg N ha−1 under the soil N application method than those under foliar N application treatments. The best N rate for optimum grain production was attained by 300 kg ha−1 with 575-mm supplemental irrigation water ha−1. The quadratic equation fitting revealed that the effect of N on crop growth parameters was higher than that of the supplemental irrigation; therefore, a water deficit may partly be managed by adding N to the soil. These water and N managements may be used in formulating agricultural practices to avoid degradation of lands for soil and environmental conditions similar to those of the current study warranting a field research.
- nitrogen optimization
- water relations