旧膜对土壤温度和向日葵产量的影响

为有效利用地膜和减少污染，于2010—2011年在内蒙古河套地区进行地膜再利用试验，分别设旧膜上种植（JS）、旧膜间种植（JJ）及露地种植（W）3个处理，研究旧膜对免耕向日葵田土壤温度变化和产量的影响。结果表明，2 a内JJ和JS处理下整个生育期0—50 cm土层温度均高于W处理，且在播种时和苗期差异显著（p<0.05），在0—10 cm土层，旧膜能有效提高土壤温度，使向日葵提前达到出苗所需的有效积温，从而促进出苗，缩短生育期。整个生育期5 cm土层的总积温（≥10℃）JJ和JS处理下分别比W处理高176.08，166.47℃，生育期较露地种植缩短5~7 d，差异性显著。土壤温度的日变化在0—20 cm呈单峰曲线，随着土层的加深和生育进程的推进，土壤温度峰值出现的时间延后，且旧膜延后于露地。JJ处理下籽粒产量在2010年和2011年较JS处理分别增加了1.34%和0.88%，较W处理分别增加了12.92%和17.82%。可见旧膜仍有利用价值，而且以旧膜间种植效果更好。

Effects of Old Plastic Film Mulching on Soil Temperature and the Yield of Sunflower

In order to make full use of plastic film and reduce the pollution, a study on re-used plastic film in Hetao area of Inner Mongolia was conducted during 2010—2011. There were three treatments including mulching and on-lines planting (JS), mulching and under lines planting (JJ) and bare field planting (W), the effects of re-used plastic film on soil temperature and sunflower yield under no-tillage were investigated. The results showed that:the temperature under JJ and JS treatments in 0—50 cm soil layer were both higher than that of W in the whole growth period with significant difference(p<0.05) in sowing stage and seedling stage. In 0—10 cm soil layer, the re-used plastic film could increase soil temperature effectively and made the effective accumulated temperature that sunflower was needed reach in advance, and then promoted the emergence and shorten growth period. In the whole growth period, the total effective accumulated temperature(≥10℃) of JJ and JS were 176.08℃ and 166.47℃ higher than that of W in 5 cm soil layer, respectively, the growth period had been shortened for 5~7 days, and the differences were significant. The daily change of soil temperature showed a single peak curve in 0—20 cm soil layer, and with the deepening of soil depth and the advancement of growth period, the time of the soil temperature peak had been delayed and the time of re-used plastic film was behind the bare field. The grain yield in 2010 and 2011 of JJ was 1.34% and 0.88% more than that of JS, 12.92% and 17.82% more than that of W. This indicated that the old plastic film also had re-used potential, and the effects of mulching and under lines planting were better.