秸秆覆盖对广西甘蔗地土壤水分变化的影响

甘磊，邓婉珍，陶涣壮，李帅，陈廷速，张建兵

摘要：【目的】研究秸稈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30～50 cm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。

关键词： 秸秆覆盖;甘蔗地;土壤含水量;水通量;广西

中图分类号： S152.7                                文献标志码： A 文章编号：2095-1191（2021）09-2438-09

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

GAN Lei1，2， DENG Wan-zhen2， TAO Huan-zhuang2， LI Shuai2，

CHEN Ting-su3， ZHANG Jian-bing4*

（1Guilin University of Technology/Guangxi Collaborative Innovation Center for Water Pollution Control and Safety in Karst Area， Guilin， Guangxi  541004，China; 2Guilin University of Technology/Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology， Guilin， Guangxi  541004， China; 3Microbiology Research Institute， Guangxi Academy of Agricultural Sciences， Nanning  530007， China; 4Nanning Normal University/Key Laboratory of Environment Change and Resources Use in Beibu Gulf， Nanning  530001， China）

Abstract：【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 populari-zing in sugarcane cultivated areas of Guangxi.

Key words： straw mulching; sugarcane field; soil water content; water flux; Guangxi

Foundation item： National Natural Science Foundation of China（42067002，41761048）; Guangxi Natural Science Foundation（2016GXNSFAA380197，2019GXNSFDA245013）

0 引言

【研究意义】土壤是作物根系伸展、固持的介质，为作物的生长发育提供必要的水分与养分。在农业生产过程中，土壤含水量对于作物的生长及产量有着十分重要的影响（侯贤清等，2018）。适宜的水分条件可促进作物根系发育，为作物地上部分提供更多养分和水分，进而提高作物产量（谢金兰等，2010），而土壤水分不足则会直接影响作物的生长速度及产量（苏坎坛等，1988）。甘蔗产业是广西农业经济发展的重要产业之一，土壤水分条件对甘蔗产量有重要影响。因降水季节分配不均，广西地区农业用水紧张（陆甲等，2015），加之桂中地区的水源涵养能力低，土壤贫瘠，阻碍了广西甘蔗种植业的发展。因此，研究甘蔗种植中如何减少棵间蒸发，保住有限的土壤水分以供甘蔗生长需要，对广西甘蔗产业的发展具有重要意义。……