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Water and nitrogen use of pearl millet and grain sorghum in Nebraska
Pearl millet [Pennisetum glaucum (L.) R. Br] and grain sorghum [Sorghum bicolor L. Moench] are drought tolerant crops that may serve as possible alternative summer crops in rotation with winter wheat [Triticum aestivum L.] in western Nebraska and may add to the diversification in cropping systems of eastern Nebraska. Two types of field experiments were conducted. The first experiment evaluated pearl millet and grain sorghum yield, water use, and yield components and their interrelation in determining yield across environmental conditions. The range of environmental conditions included the 2000 and 2001 growing seasons, a silt loam soil at Sidney and a silty clay loam soil at Mead, and four water regimes. The latter consisted of (1) no irrigation, (2) single irrigation at boot stage, (3) single irrigation at mid-grain fill, and (4) multiple irrigations. The second experiment evaluated the response of two pearl millet hybrids to N fertilizer rates of 0, 45, 90, and 135 kg N ha−1 , and N uptake and use efficiency under different environmental conditions at Mead and Sidney. ^ Across environmental conditions, pearl millet grain yields of 1.9 to 5.1 Mg ha−1 were 60 to 80% that of grain sorghum with yields of 4.1 to 6.1 Mg ha−1. Pearl millet and grain sorghum used 330 to 374 mm of water, and their grain yield increased linearly with increase in water use. Grain sorghum, with greater yields, had greater water use efficiency than pearl millet. Yield increase from irrigation was attributed to kernel weight and kernels panicle−1 at Mead, and kernel weight, kernels panicle−1 and panicles m−2 at Sidney. Stepwise regression and path analysis indicated that kernel weight was the major contributor for grain yield of both crops, except for pearl millet at Sidney where kernels panicle−1 was the largest yield contributor. Pearl millet, with lower and less stable yields, does not currently have the potential to be a substitute for grain sorghum in Nebraska. ^ The two pearl millet hybrids used had similar responses to N fertilizer and their yields, N uptake, and nitrogen use efficiency (NUE) increased with increased N rate. Maximum grain yield was reached with 90 kg N ha−1 in most environments. However, based on the different NUE components, the optimum N rate for pearl millet was 45 kg N ha−1 in all environments. ^
Maman, Nouri, "Water and nitrogen use of pearl millet and grain sorghum in Nebraska" (2003). ETD collection for University of Nebraska - Lincoln. AAI3092572.