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.