Response of hybrid maize to tillage, nitrogen and moisture regimes after irrigated wetland rice

Results indicated that the soil moisture fluctuations from alllowable depletion to permanent wilting point resulted from decreasing moisture regimes based on irrigation water (IW) to cumulative pan evaporation (CPE) ratios and increasing tillage intensity, which in turn reflected in the performance of the maize. Higher moisture regimes resulted in better crop growth, nutrient and water utilization, hence increase maize yield in terms of grain and stover yields and harvest index. The highest grain yield was obtained in the plots which received irrigation at IW/CPE=1.00 followed by the plots of IW/CPE = 0.75 and IW/CPE = 0.50 irrespective of tillage methods. However, across the moisture regimes, strip tilled plots produced the highest grain yield identically followed by conventionally tilled plots. Lowest grain yield was recorded in untilled plots. Total uptake of N was significantly increased by moisture regimes as well as tillage intensity. However, total P and K uptake were increased by moisture regimes only. In general, nutrient content was higher in the drier regimes but total uptake was increased with increasing irrigation frequency. Profile moisture contribution (PMC) and consumptive use (CU) were significantly influenced by moisture regimes as well as tillage methods. In general, water use parameters increased in the wetter regime plots but intensity of tillage resulted in decrease in the PMC, CU, and water use efficiency. Further increase of N levels from the existing recommendation (120 kg N/ha) showed positive influence on growth, yield and nutrient and water utilization of hybrid maize over tillage methods but tillage methods did not influence significantly across N levels. Grain yield response to N levels was curvilinear. Grain production increased with N levels to a maximum of 7788 kg/ha at 180 kg N/ha. Although tillage methods did not influence the grain yield of maize significantly, the economic analysis showed that strip and zero tillage methods had 17.70 and 19.77 percent higher net return, respectively, over the conventional tillage at 180 kg N/ha (P17,059.00)