%A Fang NING,Yuan-Hong ZHANG,Peng-Fei WEN,Rui WANG,Qian WANG,Zhao-Yang DONG,Guang-Can JIA,Jun LI %T Responses of maize growth and yield to nitrogen application in dryland under different precipitation conditions %0 Journal Article %D 2019 %J Acta Agronomica Sinica %R 10.3724/SP.J.1006.2019.83055 %P 777-791 %V 45 %N 5 %U {https://zwxb.chinacrops.org/CN/abstract/article_6682.shtml} %8 2019-05-12 %X

Water deficiency is a main limiting factor for maize growth in dryland. The seasonal fluctuation of precipitation and the frequent occurrence of drought have severely affected the normal growth and stable production of spring maize in Weibei dryland. An in-situ experiment was conducted in Heyang county located in Weibei dryland from 2016 to 2018, with five treatments of nitrogen rates, including 0 kg ha -1 (N0), 75 kg ha -1 (N75), 150 kg ha -1 (N150), 270 kg ha -1 (N270), and 360 kg ha -1 (N360) from 2016 to 2017 and 0 kg ha -1 (N0), 90 kg ha -1 (N90), 180 kg ha -1 (N180), 270 kg ha -1 (N270), and 360 kg ha -1 (N360) in 2018, using two spring maize varieties Zhengdan 958 (ZD958) and Shaandan 8806 (SD8806). The effects of nitrogen application rates on dynamic changes of soil moisture, dry matter accumulation, yield composition, economic returns and water use efficiency (WUE) of spring maize during growth period were analyzed in different test years. There were two distribution types of precipitation in the test years, one was rainy at the ear stage and droughty at the grain stage (2016, 2018), while the other was droughty at the ear stage and rainy at the grain stage (2017). Precipitation amount and its distribution in the growing season significantly affected soil water storage and aboveground dry matter accumulation of maize, thus affecting grain yield and its components. Drought at the ear stage significantly reduced aboveground dry matter accumulation and kernel number per ear, while drought in the grain stage decreased kernel weight. The yield of applying nitrogen fertilizer treatment was 6.72%-91.23% higher than that of N0 across three years. The effects of nitrogen rates on grain yield and WUE followed a quadratic curve relationship. In the case of being rainy at the ear stage and droughty at the grain stage there occurred the highest grain yield and WUE in N270, in contrast when it was droughty at the ear stage and rainy at the grain stage, spring maize performed better in N150 treatment. The Grain yield was positively correlated with “precipitation from fallow to tasseling” (FP2) and “the sum of soil water storage before sowing and precipitation from sowing to tasseling” (SP2) (FP2: R 2=0.839 **; SP2: R 2=0.837 **). Based on a comprehensive assessment for grain yield, WUE and net economic returns, the optimum nitrogen application rate in this study is basic fertilizer of 150 kg ha -1 plus top dressing of nitrogen fertilizer in time according to the predicted yield, which is estimated by FP2 or SP2, so as to get the optimized N fertilizer amount and maximized yield, WUE and economic returns in Weibei dryland.