不同耕作模式下旱作玉米氮磷肥产量效应及水分利用效率

为了探讨不同耕作模式下氮磷肥施用量对旱作玉米产量及水分利用效率的影响，于2003－2008年在山西寿阳旱农试验站进行了免耕、少耕和传统耕作下氮磷肥用量（105、179和210 kg/hm2 N；N∶P2O5=1∶1）试验。6 a结果显示，该区推荐氮磷用量为105 kg/hm2，传统耕作模式下玉米平均产量和水分利用效率分别为5 234 kg/hm2和12.4 kg/(hm2·mm)；少耕模式下玉米平均产量和水分利用效率分别达到5 751 kg/hm2和13.6 kg/(hm2·mm)，较传统耕作提高9.9%和9.7%。而免耕模式下氮磷用量为179 kg/hm2时玉米平均产量和水分利用效率最高，分别为5 336 kg/hm2和13.2 kg/(hm2·mm)，较传统耕作提高6.1%和9.7%。免耕模式下土壤保水效果最佳，干旱年增产作用尤为明显。3种耕作模式下玉米平均产量和水分利用效率以少耕为最高，免耕次之，传统耕作最低。

Effects of nitrogen and phosphorus on dry farming spring corn yield and water use efficiency under different tillage practices

A six-year experiment (2003 to 2008) was conducted in Shouyang Dryland Farming Experimental Station in Shanxi Province to study the effect of different tillage practices (no-tillage, reduced tillage and conventional tillage) with three nitrogen (N) and phosphorus (P2O5) fertilizer rates (105, 179 and 210 kg/hm2; N:P2O5 =1:1) on spring corn yield and water use efficiency. The results showed that at the recommended fertilizer rate of 105 kg/hm2, the average yield and water use efficiency (WUE) were about 5 234 kg/hm2 and 12.4 kg/(hm2·mm), respectively, under conventional tillage (CT), and about 5 751 kg/hm2 and 13.6 kg/(hm2·mm), respectively, under reduced tillage (RT). The average yield and WUE under RT increased by about 9.9% and 9.7%, respectively, compared to CT. Under no-tillage (NT), the average yield and WUE, at the fertilizer rate of 179 kg/hm2, were highest, about 5 336 kg/hm2 and 13.2 kg/(hm2·mm), respectively, which were about 6.1% and 9.7% higher than those under CT. The NT increased soil water contents, resulting in higher yields in dry years, compared to CT. Among three tillage practices, the average yield and WUE were ranked as RT >NT >CT.