ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

Aiming to investigate the effects of fertigation on spring maize growth, yield, and nitrogen absorption and utilization efficiency, soil NO-3N distribution and residual amount in sandy soil area in Ningxia, to provide a theoretical and experimental basis for the irrigation and nitrogen management of spring maize in this area. The plot experiments were conducted with two factors of irrigation and nitrogen. There were three irrigation levels (W0.6, 0.6KcET0;W0.8, 0.8KcET0 and W1.0, KcET0, Kc was the crop coefficients, ET0 was the potential reference crops evapotranspiration) and four nitrogen levels (N150,150kg/hm2;N225, 225kg/hm2;N300, 300kg/hm2 and N375, 375kg/hm2). The results showed that under the same irrigation levels, the dry matter accumulation rate, shoot biomass, yield, water use efficiency and nitrogen accumulation rate (except for W0.8 treatment) were increased at first, and then decreased with the increase of nitrogen application rate. The yield of W0.8N300 treatment was 16387kg/hm2, reached the maximum value. During the fast-growing period, the dry matter average accumulation rate of W1.0N300 and the nitrogen average accumulation rate of W0.8N375 treatment were the highest, which were 513.71kg/(hm2·d) and 2.75kg/(hm2·d), respectively. Compared with other irrigation treatments, the N remobilization of vegetative organs under W0.8 irrigation level was the highest, which was 84.67%. Both irrigation and nitrogen application amount were increased at the same time, and the soil NO-3N residual amount was increased gradually in the 60~100cm at the same time. At W0.6 and W0.8 irrigation levels, the soil NO-3N residual amount was mainly concentrated in the 0~60cm and 0~90cm soil layers, respectively. Considering the uneven distribution of annual rainfall in Ningxia, the results suggested that it was an appropriate schedule for spring maize in this area when the sum of irrigation and effective rainfall amount was 532mm and nitrogen application rate was 300kg/hm2.