秸秆覆盖对广西甘蔗地土壤水分变化的影响

【目的】研究秸秆覆盖对广西甘蔗地不同土层深度土壤水分时空连续变化的影响，以探求优化广西甘蔗种植中土壤水分状况的有效途径。【方法】甘蔗试验田设无秸秆覆盖（T0）和秸秆覆盖（TS）2个处理，常规耕作，并对试验区的降水量及试验田0~10 cm、10~30 cm和30~50 cm土层的土壤含水量进行连续动态监测，对比分析不同处理甘蔗地的土壤理化性质及土壤水分变化特征。【结果】秸秆覆盖可改善甘蔗地的土壤环境，提高土壤有机质含量，TS处理0~10 cm、10~30 cm和30~50 cm土层的土壤有机质含量较T0处理分别显著增加42.8%、29.1%和45.4%（P<0.05，下同）；秸秆覆盖同时可提高甘蔗地土壤的蓄水保墒能力，使土壤含水量显著增加，TS处理0~10 cm、10~30 cm和30~50cm土层的土壤含水量较T0处理分别显著增加10.5%、16.0%和11.5%。在干旱缺水条件下，与T0处理相比，TS处理提高了0~50 cm土层土壤水分的向上供给，水分运动更活跃。【结论】在广西甘蔗种植中进行秸秆覆盖可增加土壤有机质含量、降低土壤蒸散发，从而改善土壤水分条件和土壤环境，为甘蔗根系生长提供良好的土壤环境，值得在广西蔗区推广。

Effects of straw mulching on the change of soil moisture in sugarcane field of Guangxi

【Objective】 The effects of straw mulching on the spatiotemporal change of soil water in different depths of sugarcane field in Guangxi were studied to find an effective way to optimize the soil water condition in sugarcane field in Guangxi.【Method】 The experiment was conducted in a sugarcane field in Guangxi with two treatments:no straw mulching(T0)and straw mulching(TS). Rainfall data during the experiment period as well as the soil water content at 0-10 cm,10-30 cm,and 30-50 cm depth of the fields were collected through continuous dynamic monitoring to analyze the change of soil moisture and the soil physical and chemical properties under different conditions.【Result】 Straw mulching could improve the soil environment of sugarcane field and improve the soil organic matter content. The organic matter content in TS in 0-10 cm,10-30 cm,and 30-50 cm depths significantly increased by 42.8%,29.1% and 45.4%,respectively compared with T0(P<0.05,the same below). Meanwhile,straw mulching could improve the water retention ability of sugarcane soil and significantly enhance the soil moisture content. The soil water content under TS treatment was significantly increased by 10.5%,16.0% and 11.5%,respectively in 0-10 cm,10-30 cm and 30-50 cm depths. Compared with T0 treatment,TS treatment increased the soil upward water supply of 0-50 cm depth,which resulted into the more activewater movement during the water shortage.【Conclusion】 Straw mulching can reduce soil evapotranspiration and increase soil organic matter content,there by improving soil water conditions and soil environment in sugarcane planting in Guangxi,and provide a good soil environment for sugarcane root growth. It is also suggested that straw mulching is worth popularizing in sugarcane cultivated areas of Guangxi.