农业工程学报2017，Vol.33Issue(5)：115-121,7.DOI:10.11975/j.issn.1002-6819.2017.05.017
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
摘要
Abstract
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 thesoil 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 3 gradients by design (0,3 and 5 g/L) for better simulating a saline soil irrigation area.Irrigation amount of each treatment was 35 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 frout 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 irrigation and reduce the salt accumulation,and the treatments with 40 cm and 60 cm burial depth could reduce the salinity variation by 19.61％ and 15.68％,respectively,compared to the treatments of CK.When the brackish water was used to irrigate,the salinity of irrigation water and the depth of straw piece buried both had impact on the effect of drainage and desalination.Increasing the salinity of irrigation water or burying straw pieces deeper could improve the performance of drainage and decreasing the salinity of water combined with straw piece deeply buried body could show better desalting effect.The research provides a new way of straw utilization in field and also a reliable technique for the development and utilization of brackish water irrigation in saline soil.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Key words
drainage/infiltration/soil moisture/straw draining piece/saline soil/brackish water/water-salt distribution分类
农业科技引用本文复制引用
陆培榕,张展羽,冯根祥,万长宇,史栩帆..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[J].农业工程学报,2017,33(5):115-121,7.基金项目
国家自然科学基金资助项目(51579069) （51579069）
高等学校学科创新引智计划项目(B12032) （B12032）
中央高校基本科研业务费(2015B42314) （2015B42314）
