土壤水分与覆盖对夏玉米生长及水分利用效率的影响

在防雨棚下的测坑中,采用裂区试验设计,研究土壤高水分(75%田间持水量,下同)、中水分(65%)和低水分(55%)条件下地膜覆盖、秸秆覆盖和不覆盖对夏玉米生长发育、产量性状和水分利用效率的影响。结果表明,在不同土壤水分条件下,地膜覆盖、秸秆覆盖处理的株高和叶面积指数均高于不覆盖的处理;在玉米生长前期地膜覆盖处理的株高和叶面积指数最高,在玉米生长的中后期秸秆覆盖处理的株高和叶面积指数最高。地膜和秸秆覆盖均具有显著的增产作用,与不覆盖相比,平均分别增产8.89%和22.26%。水分利用效率(WUE)随着土壤水分的降低而增加;在相同的土壤水分条件下,秸秆覆盖处理的WUE最高,地膜覆盖的次之,不覆盖的最低;当土壤水分控制下限为田间持水量的65%时,覆盖处理的节水增产效果最好,其中地膜和秸秆覆盖处理产量比不覆盖处理分别增加12.69%和28.47%,WUE分别提高21.78%和34.65%。

Effects of Soil Moisture and Mulches on the Growth and the Water Use Efficiency of Summer Maize

A randomized split-plot design was used to conduct an experiment on the effects of polyethylene film mulching, straw mulching and no mulching under soil moisture treatments of high, medium and low(75%, 65% and 55% of field capacity) on growth development, yield, and water use efficiency(WUE) of summer maize sowed in lysimeters under a rainshelter. The results showed that plant height and leaf area index(LAI) of summer maize under different soil moisture were higher in polyethylene film mulching and straw mulching than in no mulching treatment. During the early growth period of maize, plant height and LAI of summer maize in polyethylene film mulching were the highest, but during mid-late growing period of maize, those in straw mulching treatment were maximum. Compared to no mulching treatment, polyethylene film mulching and straw mulching played a significant role in increasing maize yield, namely, increased average yield by 8.89% and 22.26% respectively. WUE decreased with increasing soil moisture, the WUE of straw mulching at the same level of soil moisture was the highest, polyethylene film mulching next, and no mulching was the minimum. When the lower limit of soil moisture is 65% of field capacity, mulching could obtain the best effect of saving water and increasing yield compared to no mulching, and polyethylene film mulching and straw mulching increased yield by 12.69% and 28.47% as well as improved WUE by 21.78% and 34.65% respectively.