滴灌施肥对华北小麦-玉米产量和水分利用效率的影响

Impact of Drip Fertigation on Yields and Water Use Efficiency of Wheat-maize Rotation in North China

【目的】研究不同滴灌施肥处理对华北地区小麦-玉米生长状况、产量和WUE的影响。【方法】采用二因素裂区设计,小麦和玉米试验施氮量设置低氮(60%当地通用施氮量)、中氮(当地通用施氮量)和高氮(140%当地通用施氮量)3个水平,分别用Nl、Nm、Nh表示;滴灌施肥次数小麦为0、1、2次,玉米为0、2、3次,分别用D0、D1、D2和D0、D2、D3表示,另以当地常规灌溉和施肥措施为对照(FP)。【结果】小麦试验结果表明,滴灌施肥可促进叶片生长,开花期滴灌施肥能减缓小麦叶面积指数(LAI)下降速率,增加干物质积累速率,不同施氮量处理之间干物质累积量差异不明显,表明滴灌施肥条件下在一定程度减少施氮量并不影响干物质积累;增加滴灌施肥次数可显著增加小麦产量,D2和D1处理的小麦平均产量分别较D0增加了44.4%和32.7%,但对WUE没有明显影响;滴灌施肥处理提高小麦产量的途径主要是通过促进千粒质量和穗数增加而实现。玉米试验结果显示,营养生长阶段滴灌施肥处理对LAI有显著促进作用,但滴灌施肥次数对地上部干物质积累没有显著影响;产量随滴灌施肥次数的增加而增加,D3处理显著高于D0处理,而WUE随滴灌次数增加而减少,D3处理显著低于D2和D0处理;与FP比较,滴灌施肥处理WUE显著高于FP,小麦和玉米的水分利用效率分别提高17.2%和7.2%以上。【结论】施氮量对小麦和玉米的产量和水分利用效率没有显著影响,表明在偏丰水年采用滴灌施肥一体化技术,在目前施肥水平基础上减少40%施氮量不会造成产量损失。

【Objective】This paper aims to study water use efficiency and yields of wheat-maize rotation under drip fertigation in North China.【Method】A field plot experiment was conducted from 2015 to 2016 using a randomized complete block split plots. We considered three nitrogen applications： 60%, 100% and 140% of N fertilizer used by local farmers. For each treatment, the N fertilizer was applied to the plots with（1）no irrigation, irrigating once or twice to the wheat,（2）no irrigation or irrigating twice or three times to the maize; the control was the business as usual as used by the local farmers.【Result】Both leaf area index（LAI） and dry mass accumulation increased with fertigation during anthesis, and the yield of the wheat increased with drip irrigation frequency. However, the drip fertigation had no significant impacts on water use efficiency（WUE） and the grain yield. Increasing irrigation frequency led to a rise in leaf area index of the maize during vegetative growth period, but had no significant effect on dry mass accumulation while reducing the WUE. Drip irrigation frequency was found to have a significant impact on grain yield. Compared with the control, drip fertigation increased WUE by 17.2% and 7.2% for wheat and maize respectively.【Conclusions】Our findings suggest that there is no significant difference in yields and WUE under different N applications, and reducing N fertilizer application currently used by local farmers by 40% does not lead to a noticeable reduction in grain yield.