干旱区微咸水滴灌条件下典型土壤盐碱化影响因素研究

摘要

In order to study the change of soil salinity,soil alkalinity and main cations under long time drip irriga-tion with different concentration of brackish water in alluvial fan of the edge and the dry delta area in Manas River Basin, taking the representative sandy loam and clay loam soil in cotton field as the research object,using the high and low saline water for 5 years irrigation,has set up four treatments as clay loam-low salinity,clay loam-high salinity,sandy loam-low salinity and sandy loam-high salinity,measured the soil total salt,pH,Na +,K+,Ca2 +,Mg2 +,SAR,ESP, etc.in 0 ~100 cm soil layers,discussed the ions that have produced the main impact to soil salinization and alkaliza-tion,to provide the theoretical reference of ecological security for brackish water irrigation in arid area.The results indi-cated that:The soil salinization and alkalization in clay loam of alluvial fan of the edge and sandy loam of the dry delta area was together occurred,also was mainly affected by irrigation water salinity.The ion of main influence for soil salin-ization and soil alkalization was Na +and for soil salinization was Na +and Ca2 +.It indicated that amelioration of the soil salinization in Manas River Basin should be started with reducing irrigation water Na +,and combined control of total salt content in irrigation water with reducng the proportion of Na + to achieve the purpose of reducing salt and preventing and controlling soil alkalization.%以代表性的沙壤和黏壤棉田土壤为研究对象，分别利用高、低矿化度水进行5年灌溉，即黏壤－低矿化度，黏壤－高矿化度，沙壤－低矿化度，沙壤－高矿化度共四个处理，测定0～100 cm 分层土样总盐、pH、Na ＋、K＋、Ca2＋、Mg2＋、SAR、ESP 等指标，以研究玛纳斯河流域冲积扇扇缘和干三角洲区不同浓度微咸水长期滴灌条件下土壤盐分、土壤碱度、主要阳离子的变化，探讨对土壤盐化和碱化产生主要影响的离子，为干旱区微咸水灌溉生态安全管理提供理论参考。结果表明：冲积扇扇缘带黏壤土和干三角洲沙壤土盐化和碱化相伴发生，且主要受灌溉水矿化度影响；对土壤盐化和碱化均产生主要影响的离子为 Na ＋，对土壤盐分产生主要影响的离子为 Na ＋与 Ca2＋。这表明玛纳斯河流域土壤盐碱化的治理应从降低灌溉水 Na ＋入手，将控制灌溉水总盐分和降低 Na ＋占比结合起来，达到既降盐又防治土壤持续碱化的目的。