环渤海盐碱化潮土区小麦-玉米轮作体系氮肥用量对氮肥利用率的影响

Effects of Nitrogen Amount of Wheat-maize Rotation System in Salinized Soil around Bohai Sea on Nitrogen Utilization Ratio

采用田间小区试验,研究了环渤海盐碱化潮土区高、中、低产田小麦-玉米最佳施氮量,以及不同施氮水平对小麦-玉米产量、氮肥贡献率和氮肥利用率的影响。结果表明:对于高、中、低产田,小麦的适宜施氮量分别为225,225,180kg/hm2,玉米的适宜施氮量分别为225,180,135kg/hm2;氮肥贡献率在低产田和中产田上大于高产田;氮肥吸收利用率为低产田>中产田>高产田,氮肥吸收利用率和氮肥偏生产力随氮肥用量增加而降低;高、中、低产田土壤供氮能力在冬小麦茬口分别为82.2%,77.8%,76.8%,在夏玉米茬口分别为81.9%,77.7%,75.9%。

A field experiment was conducted to study the optimum nitrogen application of wheat-maize in the high, medium and low yield fields of salinized soil around Bohai Sea, as well as the effects of different nitrogen level on wheat-maize yield, nitrogen contribution rate and nitrogen utilization ratiol The results show that the suitable amount of nitrogen applied for high, medium and low yield fields of wheat is 225 kg/hm2, 225 kg/hm2 and 180 kg/hm2 respectively, and 225 kg/hm2, 180 kg/hm2 and 135 kg/hm2 of maize. The nitrogen contribution rate in the low and medium yield fields is larger than that in the high yield fields. The nitrogen absorption and untilization rate in the low yield fields is higher than that in the medium yield fields, and the rate in the medium yield fields is higher than that in the high yield fields. The nitrogen absorption and utilization rate and nitrogen partial productivity are decreased with the increase of nitrogen amount. The soil nitrogen supplying capacity in the high,medium and low yield fields of wheat is 82.2%,77.8% and 76.8%, that in maize fields is 81.9%,77.7% and 75.9%, respectively.