滴灌条件下减量施肥对玉米产量及肥料利用率的影响

Effects of reduced fertilization on yield and fertilizer use efficiency of maize under drip irrigation

为提高滴灌条件下的肥料利用效率,降低因过量施肥引起环境污染的风险,2015—2016年在河套灌区研究了在常规施肥(NPK)基础上减氮12%(N1PK)、减氮24%(N2PK)、减氮36%(N3PK)和减氮48%(N4PK)对玉米产量及肥料利用率的影响,结果表明,与常规施肥相比,少量减氮处理N1PK和N2PK对玉米的生长发育和产量构成因素影响不大,对产量也没有显著影响;减氮量较大的N3PK和N4PK处理降低了玉米行粒数和百粒重,增加了秃尖长度,两年平均,N3PK和N4PK处理分别使产量降低了7.9%和13.0%。氮肥的利用率随着氮用量的减少而升高,两年平均从29.3%提高到35.7%。磷肥的利用率随着氮肥用量的增加先升高后降低,不同处理相比,N1PK和N2PK处理的磷肥利用率最高,分别为19.9%和20.0%。综合考虑,在河套灌区的滴灌条件下,氮肥用量在现有的用量基础上减少12%~24%,可以在不减产的前提下获得较高的肥料利用率,减氮36%~48%则会使产量显著降低。

In order to improve the utilization efficiency of drip irrigation fertilizer, and reduce the risk of environmental pollution caused by excessive fertilization, a field experiment was carried out in Hetao Irrigation District in 2015—2016 and the effects of conventional fertilization（NPK） and 12% reduction in nitrogen（N1 PK） and 24% reduction in nitrogen（N2 PK） and 36% reduction in nitrogen（N3 PK） and 48% reduction in nitrogen（N4 PK） on yield and fertilizer efficiency of maize were studied. The results showed that the treatment of N1 PK and N2 PK had little effect on the growth and yield components of maize, and had no significant effect on Yield. The treatment of N3 PK N4 PK reduced the grain number and100 grain weight, were increased the bald tip length. On average, N3 PK and N4 PK treatments reduced production by 7.9%and 13%, respectively. On average, the utilization rate of N increased with the decrease of the amount of nitrogen fertilizer,from 29.3% to 35.7%. The utilization rate of phosphate fertilizer increased first and then decreased with the increase of nitrogen application rate and reached the highest in the treatment of N1 PK and N2 PK, the average was 19.9% and 20.0%respectively. In summary, the amount of nitrogen fertilizer which was reduced by 12% -24% on the basis of the existing fertilizer amount could obtain higher fertilizer utilization rate without reducing yield in the drip irrigation condition of Hetao irrigation district.