氮肥施用量对砂壤质潮土玉米生长及水分利用效率的影响

Effects of Nitrogen Fertilizer on Growth and Water Use Efficiency of Maize in Sandy-loam Alluvial Soil

为探明氮肥施用量对玉米生长及水分利用的影响,采用田间试验研究了氮肥不同用量[N0(对照):0kg/hm2、N1:90kg/hm2、N2:180kg/hm2、N3:270kg/hm2、N4:360kg/hm2、N5:450kg/hm2、N6:540kg/hm2]对玉米不同生育期土壤水分、农艺性状、成产要素、产量及水分利用的影响。结果表明,总体上,施用氮肥尤其是N5处理增加了上层土壤的含水率,并促进了玉米根系下扎深度,使玉米利用了较多的深层土壤水;在不同生育期,以N5和N6处理的形态指标表现最佳;穗长、穗粗、穗行数、行粒数等玉米成产要素以N5处理最高。随施氮量的增加,玉米产量显著提高,但当氮肥用量高于450kg/hm2时,玉米产量增幅不明显;水分利用效率呈先增加后降低的趋势,以N5处理最高,其产量(12 093.0kg/hm2)和水分利用效率[24.4kg/(mm·hm2)]分别较对照增加70.7%和78.1%。综上所述,玉米的最佳施氮量为450kg/hm2。

In order to ascertain the characteristics of growth and water utilization of maize under different amount of nitrogen fertilizer, a field experiment was conducted to investigate the effect of nitrogen fertilizer with dosage of 0 kg/ha （CK）, 90 kg/ha （N1）, 180 kg/ha（N2）, 270 kg/ha （N3） ,360 kg/ha（N4）,450 kg/ha（N5）,540 kg/ha（N6）on soil moisture, maize agronomic charac- ters, production elements, yield and water utilization. The results indicated that application of ni- trogen fertilizer, especially 450 kg/ha increased the upper soil water content, and promted the maize root deep growth, so the maize could rse more deep soil water. The corn morphological indexes of the treatment with 450 kg/ha nitrogen in different growth period had better performance, and the production elements such as ear length, ear coarse, ear number of rows, row grains were higher compared with CK. With the increase of nitrogen rate, maize yield increased significantly, but when nitrogen fertilizer Was higher than 450 kg/ha,the increase rate of maize yield decreased obviously. And water use efficiency first increased and then dropped with the increase of nitrogen.The water use efficiency（WUE） of the treatment with 450 kg/ha nitrogen was highest and the yield （12 093.0 kg/ha）and WUE （E24.4 kg/（mm ~ hm2）~） were 70.7% and 78.1% higher than CK. It was concluded that the treatment with 450 kg/ha nitrogen was the most promising option.