不同土壤肥力条件下高产玉米氮肥最佳用量研究

通过田间试验,研究了不同施氮量对春玉米产量、氮肥利用率及土壤硝态氮累积的影响。结果表明,东阳、祁县和文水3个试验点最佳经济施氮量分别为227,204,201 kg/hm2,施氮量增加到一定值时,产量便不再增加;随着施氮量的增加,3个试验点春玉米的氮效率呈下降趋势,N180,N270处理的氮效率要高于其他处理;玉米收获后的0～90 cm土壤硝态氮累积呈现出东阳N270之后的处理,30～90 cm土层的硝态氮盈余现象严重,祁县和文水试验点N180处理的硝态氮累积量适宜,之后的处理氮素盈余现象严重。参考不同施氮量对春玉米产量、氮肥利用率及土壤硝态氮累积的影响,认为在中低肥力的东阳试验点,施氮量为225 kg/hm2时,在保证高产的同时又不会对环境构成威胁,在中等肥力的祁县和高肥力的文水试验点,可能由于土壤质地和气候的差异,氮肥推荐量为200 kg/hm2时可以同时兼顾经济效益和环境效益。

Optimum N Application Rate at Different Soil Fertility Levels in Spring Maize

Field experiments were conducted to study the effect of different nitrogen application rates on spring maize in yield,nitrogen utilization and soil nitrate nitrogen accumulation.The results showed that the optimum economic N application rates under economic optimum yields were N 227 kg/hm 2,204 kg/hm 2 and 201 kg/hm 2 for Dongyang,Qixian and Wenshui respectively. When nitrogen application rates increased to a certain value,the yield would no longer increase.The nitrogen use efficiency decreased with the increase of nitrogen application rates,the nitrogen efficiency of N180 and N270 treatment would be higher than the other treatments.The residual nitrate nitrogen in 0-90 cm soil showed as following: the nitrogen application rate higher than 270 kg/hm 2 in Dongyang and 180 kg/hm 2 in Qixian and Wenshui resulted in luxury nitrate accumulation in soils.The research analyzed the effects of different nitrogen application rates on spring maize in yield,nitrogen use efficiency and soil nitrate nitrogen accumulation.It suggested that the nitrogen at the rate of 225 kg/hm 2 could satisfy the maize demand and would not threaten the environment in Dongyang with lower soil fertility,and the nitrogen application rate should be controlled below 200 kg/hm 2 in medium fertility Qixian and high fertility Wenshui.