为弄清膜下滴灌农田土壤次生盐渍化迁移和转化特点,了解新疆滴灌农田土壤次生盐渍化演化机制,试验设置3个灌溉量水平(3600m3/hm2、4200m3/hm2和4800m3/hm2),研究灌溉量对土壤盐分类型及盐分运移的影响.结果表明,随着灌溉量增加,土壤总盐含量分别降低45.36%、57.94%、61.14%,灌溉起到洗盐作用.灌溉前、后土壤主要盐基阴离子类型由Cl--SO42-型转为SO42-型,阳离子由M2+-Na+型转为Na+型,土壤主要盐分由Na2SO4、NaC1、MgSO4、MgCl2转为Na2SO4.由于HCO3-在土壤中积累且灌溉水不断补充Na+,使NaHCO3含量增加,可能导致土壤苏打盐化或碱化.
To understand the change characteristic of soil salt and change mechanism of soil secondary salinity under the condition of cotton farm mulched drip irrigation in Xinjiang,a field experiment with 3 levels of irrigation amounts(3600 m3/ha,4200 m3/ha and 4800 m3/ha)was carried out to study the influence of irrigation amount of mulched drip irrigation on soil salt.Results showed that the content of total salt of soil decreased by 45.36 %,57.94% and 61.14%,respectively,with increasing irrigation amount.The types of negative and positive ions changed from Cl--SO42-and Mg2+-Na+ to SO42-and Na+,respectively,after irrigation,which made the main type of salt change from Na2SO4、NaCl、MgSO4、MgCl2 to Na2SO4.However,HCO3-and Na+were accumulated in soil with irrigation,which might result in soil secondary salinization or alkalization.