河套灌区盐渍农田分布广、肥力质量差、生产力水平低，严重威胁粮食安全。为研究秸秆–保水剂复合隔层对河套灌区盐碱土的控盐及节水效果，通过室内土柱模拟试验，设置常规灌溉水量（10 L）和节水20%灌溉水量（8 L）2种灌溉水量下的2种隔层（秸秆隔层和复合隔层）以及对照组处理，对比研究了复合隔层与秸秆隔层在节水条件下对土壤水分入渗过程、蒸发过程以及盐分变化规律的影响。研究结果表明：入渗过程中，两种隔层均能延缓水分入渗，提高淋盐效果，相比秸秆隔层，复合隔层处理水分入渗时间延缓14.47%，对0~40 cm土层淋盐效果提升34.86%。蒸发过程中，复合隔层能够通过内部保水剂缓慢释水，对20~40 cm土层补水，其20~40 cm土层含水率较秸秆隔层提升10.90%~90.61%。节水20%的条件下，复合隔层处理在0~40 cm土层的灌溉淋盐效果及蒸发过程中的保水抑盐效果优于未进行节水处理的对照组。综合来看，秸秆–保水剂形成的复合隔层其淋盐效果、保水抑盐效果均优于秸秆隔层，在节水条件下仍具有较好的保水控盐效果。本研究可为河套灌区节水型盐碱障碍消减研究提供依据和参考。

Saline farmland in Hetao irrigation area is widely distributed with poor fertility and low productivity, which seriously threatens food security. In order to study the salt-control and water-saving effects of straw-water-retaining agent composite layer on saline-alkali soil in Hetao irrigation district, an indoor soil column simulation experiment was conducted with straw and composite layers under conventional (10 L) and 20% water-saving (8 L) irrigation water. Soil water infiltration, evaporation and salinity variation were determined and compared under different treatments. The results showed that both layers delayed water infiltration and improved salt leaching effect during infiltration process compared with CK (no interlayer and 10 L irrigation). Compared with straw layer, the composite one delayed water infiltration time by 14.47%, and increased salt leaching effect by 34.86% in 0-40 cm soil layer. In the evaporation process, the composite layer slowly released water to 20-40 cm soil layer through internal water retaining agent, and soil moisture in 20-40 cm layer was increased by 10.90%-90.61% compared with the straw layer. Under 20% water saving, the above effects in 0-40 cm soil was better for the treatments with composite layers than CK. In summary, the composite barrier of straw and water retaining agent has better effect on water and salt control than straw barrier even under the condition of water saving, which provide basis and reference for the reduction of water-saving saline-alkali barrier in Hetao irrigation district.

S156.4

国家重点研发计划项目（2021YFD1900602，2021YFC3201201）和国家自然科学基金项目（41977015）资助。