不同改良措施对新疆盐渍化棉田的改良效果

Study on the Effects of Different Improvement Measures on Salinized Cotton Field in Xinjiang

【目的】研究不同盐渍化改良措施与农业措施相结合,对土壤剖面盐分和0~80 cm耕层脱盐效果,为实现重度盐渍化土壤的资源可持续利用提供理论依据。【方法】以新疆玛纳斯河流域重度盐渍化土壤为研究对象,设置3种改良方案(T1:农业改良措施、T2:根区隔离土壤盐分+农业改良措施、T3:暗管排水处理+农业改良措施),通过3年的大田试验,分析0~80 cm土壤剖面盐分分布与盐分含量变化。【结果】不同改良措施地下水埋深随着生育期的灌溉表现出相似的变化规律,暗管排水措施对地下水埋深具有较好的调节效果;根区隔离、暗管排水措施与农业改良措施相结合均能够快速有效降低土壤盐分,根区隔离措施底层(40~80 cm)土壤脱盐效果较强,盐分含量降低了8.92 g/kg,暗管排水措施在表层(0~40 cm)土壤盐分含量降低了6.30 g/kg,具有较强的脱盐效果,农业改良措施在耕层(40~80 cm)土壤整体盐分含量降幅相对较低;结合3年的脱盐率变化来看,2016年脱盐率较低,2017年研究区脱盐率大幅度提升,根区隔离措施、暗管排水措施耕层(0~80 cm)土壤平均脱盐率分别为63.30%、52.47%,明显高于农业改良措施脱盐率30.67%,2018年农业改良措施、根区隔离措施以及暗管排水措施在0~80 cm土层脱盐率分别为5.28%、20.00%、3.89%。【结论】根区隔离、暗管排水工程措施结合农业改良措施,能够快速有效降低土壤盐分含量,改善重度盐渍化土壤。

【Objective】To study the desalination effect of different salinization improvement measures combined with agricultural measures on soil profile salinity and 0-80 cm tillage layer,in the hope of providing theoretical basis for sustainable utilization of resources in severely salinized soil.【Method】Three improvement schemes(T1,agricultural improvement measure,T2,root zone isolation soil salinity+agricultural improvement measure,T3,underground drainage treatment+agricultural improvement measure)were set up to study the salinity distribution and salinity content change in 0-80 cm soil profile through three years of field experiments.【Result】Groundwater burial depth of different improvement measures showed similar change regularity with irrigation in growing period.Underground drainage measures had better regulation effect on groundwater burial depth.The combination of root zone isolation,underground drainage measures and agricultural improvement measures could rapidly and effectively reduce soil salinity,and the bottom layer of root zone isolation measures.(40-80 cm)Soil desalination effect was stronger,and the salt content was reduced by 8.92 g/kg,and the salt content of the surface soil by 6.30 g/kg by the underground drainage measures.Agricultural improvement measures had a relatively low overall salt content reduction in the plough layer(40-80 cm).Combined with the three-year desalination rate,the desalination rate was lower in 2016.In 2017,the desalination rate in the study area increased significantly.The average desalination rates of the cultivated layer(0-80 cm)were 63.30%and 52.47%respectively,which were significantly higher than that of the agricultural improvement measures(30.67%).In 2018,the desalination rates of the agricultural improvement measures,the root-zone isolation measures and the underground pipe measures were significantly higher than those of the agricultural improvement measures(30.67%).The desalination rates of drainage measures in 0-80 cm soil layer were 5.28%,20.00%and 3.89%,respectively.【Conclusion】Root-zone isolation and underground drainage engineering combined with agricultural improvement measures can rapidly and effectively reduce soil salinity and improve the severely salinized soil.