秸秆排水体埋深对盐渍土水盐分布的影响及排水抑盐效果  

Effect of straw draining piece depth in soil on water-salt distribution in saline soil and its drainage-salt inhibiting performance

作　　者：陆培榕 张展羽[1,2] 冯根祥 万长宇 史栩帆 

机构地区：[1]南方地区高效灌排与农业水土环境教育部重点实验室,南京210098 [2]河海大学水利水电学院,南京210098

出　　处：《农业工程学报》2017年第5期115-121,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(51579069);高等学校学科创新引智计划项目(B12032);中央高校基本科研业务费(2015B42314)

摘　　要：为探究秸秆排水体对盐渍土水盐运移的影响及其排水排盐效果,通过室内土柱试验,研究在淡水(CK)和微咸水灌水情况下秸秆排水体埋深为40和60 cm时供试土壤的水盐分布状况。结果表明,入渗阶段,湿润锋与入渗时间呈幂函数关系,累积入渗量与入渗时间则可采用Kostiakov模型进行拟合;蒸发阶段,秸秆排水体对埋设深度以下的土体具有明显的保水作用,40 cm埋深的处理在40~70 cm土层范围以及60 cm埋深的处理在50~70 cm土层范围土壤水分变化的相对变化量均>0;秸秆排水体有利于保持灌水后土壤的脱盐状态,40 cm埋深处理和60 cm埋深处理比无埋设的对照处理分别减少了19.61%和15.68%的盐分变化量;秸秆体的排水排盐效果与灌水矿化度和秸秆排水体埋深密切相关,灌溉水矿化度适当的增加和秸秆体的埋设加深将有利于排水效果的提升,低灌溉水矿化度结合秸秆体深埋具有更好的排盐效果。该研究为微咸水灌溉及盐渍土的开发利用提供依据和参考。To explore the drainage performance of straw draining piece and the soil water-salt movement in saline soil,a soil column experiment was established at an indoor laboratory in Hohai University.The soil water salt distribution under the irrigation condition of different salinity of brackish water with the straw draining pieces buried in 40 and 60 cm depth in the soil was investigated.A cylinder drainage body of 40 cm in height and 15 cm in diameter was made using rice straws,enveloped in 5 cm thick non-woven fabric and bound into shape using a plastic cord.The irrigation water was available in 3gradients by design（0,3 and 5 g/L）for better simulating a saline soil irrigation area.Irrigation amount of each treatment was35 L to simulate the waterlogging soil condition.The soil column simulated a soil having an initial salinity of 5 g/kg.The groundwater depth was maintained at 80 cm by connecting to an external Markov bottle and the groundwater salt content was set at 5 g/L.The test was conducted to determine,in the irrigation process,the wetting front distance and cumulative infiltration.Soil salinity and moisture（by mass）in different soil layers at 1 and 25 d after irrigation were determined.Relative change of soil moisture variation after 25 d of irrigation was calculated to reveal the ability of inhibiting soil evaporation or leakage of straw piece.In the drainage process,the drainage,salt removal,drainage efficiency and salt removal efficiency were then estimated from these measurements.The results showed that the infiltration duration and the wetting front distance conformed to a power function,the infiltration rates of soils with straw draining piece could be simply fitted by Kostiakov equation.Straw piece had the ability to inhibit soil moisture variation and groundwater reverse osmosis effect,the relative change of soil moisture variation in the soil depths below the straw piece was above 0 both in the treatment with 40 or 60 cm burial depth.Straw piece also helped keep the desalination state after ir

关 键 词：排水 入渗 土壤水分 秸秆排水体 盐渍土 微咸水 水盐分布 

分 类 号：S156.42[农业科学—土壤学]