沟垄全覆盖种植方式对旱地玉米生长及水分利用效率的影响

Effects of planting with ridge and furrow mulching on maize growth,yield and water use efficiency in dryland farming

2008—2010年在渭北旱塬区,以沟不覆盖为对照(CK),研究垄上覆地膜沟内分别覆普通地膜(PP)、生物降解膜(PB)、玉米秸秆(PS)和液体地膜(PL)4种沟垄全覆盖种植模式对土壤水温、玉米生长、产量及水分利用效率的影响。结果表明,在玉米生长前期,PP、PB和PS处理可明显提高0—200 cm土壤蓄水量;生育中期,PS处理蓄水保墒效果最为显著;生育后期,各沟垄全覆盖处理与对照的土壤蓄水量无显著差异;整个生育期PL处理与CK的土壤蓄水量差异不显著。PP和PB处理3a玉米生育期5—25 cm平均土壤温度分别较CK增高1.6℃和1.3℃,PS处理降低1.9℃,而PL处理与CK无显著差异。PP和PB的增温保水效应使玉米株高、叶面积及地上生物量均高于CK;PS处理的降温效应促进玉米中后期生长,其株高、叶面积及地上生物量均高于CK;PL处理对玉米各生长指标影响不显著。与CK相比,PP、PB和PS处理3a平均的籽粒产量分别提高13.0%、13.8%和15.0%,水分利用效率分别提高9.8%、10.2%和11.6%。可见,垄覆地膜沟覆地膜、生物降解膜或秸秆的沟垄全覆盖种植可明显改善土壤的水温状况,促进玉米生长,从而显著提高作物产量和水分利用效率,对渭北旱塬区春玉米丰产栽培具有重要指导意义。

From 2008--2010, we conducted a field experiment in the Weibei Highlands to determine the effects of planting with ridge and furrow mulching on the soil water and temperature, and the maize growth, yield, and water use efficiency. Ridges were covered with plastic film in all treatments, while furrows were mulched with plastic film （PP）, biodegradablefilm （PB）, corn straw （PS）, or liquid film （PL）. In the control treatment （CK）, ridges were covered with standard plastic film, while furrows received no mulching. The three-year trial showed that, during the early maize growth stage, the soil water storage （0--200 cm） was significantly higher with the PP, PB, and PS treatments compared with CK. The three-year average water storage increased by 14.1, 17.9, and 22.2 mm compared with CK. Our analysis of the vertical distribution of the soil water content in the 0--200 cm soil profile showed that the soil water content at the 0--20 cm and 100--200 cm depth were higher with PP, PB, and PS compared with CK. The effect of PS on water conservation was the highest during the middle growth stage, while the three-year average water storage was 16.9 mm higher with the PS treatment than CK. However, the soil storage with PP and PB was significantly lower than CK in 2008 and 2009. Compared with CK, the soil water content with PP and PB increased significantly at the 0--200 cm depth, whereas it decreased at the 80--180 cm depth. There were no significant differences among the mulching treatments during the later growth stage. Soil water storage was slightly higher with PL than CK, while there were no differences in soil water storage between the two treatments during the entire maize growing season. The three-year mean soil temperatures （5--25 cm） with the PP and PB treatments were 1.6 °C and 1.3 °C higher than CK, respectively, whereas the PS treatment was 1.9 °C lower than CK. However, there was no significant difference in the soil temperature with the PL treatment and CK during the maize growing season. The water retention and temperature-raising effects of the PP and PB treatments increased the plant height, leaf area, and aboveground biomass by 2.3% and 2.4% , 30.9% and 29.9% , and 15.5% and 13.9% , compared with CK, respectively, while the maize growing period was reduced by 5--6 d. The cooling effect of the PS treatment also increased the plant height, leaf area, and aboveground biomass by 7.0% , 34.6% , and 6.5% compared with CK, respectively, although the growing period was extended by 4--5 d. There was no difference between the maize growth indices of the PL treatment and CK during the entire maize growing period. PP, PB, and PS produced a higher maize yield and water use efficiency throughout the experimental period. Compared with CK, the PP, PB, and PS treatments increased the three-year mean maize yields by 13.0% , 13.8% , and 15.0% , with water use efficiency improvements of 9.8% , 10.2% , and 11.6% , respectively. Therefore, covering ridges with plastic film and mulching furrows with plastic film, biodegradable film, or corn straw, greatly improved the soil water and temperature status, promoted maize growth, and significantly increased the crop yield and water use efficiency. These results may have important implications for maize production in the Weibei Highlands, China.