冻融期盐渍化土壤水盐分布的变化特征

摘要

以北疆地区膜下滴灌棉田不同程度盐渍化土壤为试验区,冻融期在0、20、40、60、80、100 cm取样,研究冻融期土壤水盐运移规律和分布变化.结果表明,冻融期浅层土壤积盐;在0~20 cm,轻度盐渍化土壤的积盐率比盐土高1.54%、土壤盐分变异程度是盐土的1倍.冻结期在60 cm土壤形成低含水率区,冻融期末在0~20 cm土壤含水率盐土比轻度盐渍土高13.3%.冻融使土壤水盐发生重新分布,不同程度盐渍化土壤冻融期土壤水分和盐分变化趋势和幅度的差异显著(P<0.05).%Different degrees of saline soil under mulch drip irrigation in Northern Xinjiang were taken as experimental area and samples were collected in 0,20,40,60,80 and 100 cm depth to study soil water and salt transport law and distribution changes during freezing and thawing periods.The results showed that soil salt accumulated in shallow soil layer during freezing and thawing periods.At 0-20 cm,the salt accu-mulation rate in slightly salinized soil was 1.54% higher than that of highly salinized soil,and the salinity variation of low salinity soil was about 1 times higher than that of high salinity soil.Freezing period formed low water content zone in 60 cm soil,and at the end of freezing and thawing periods,the soil moisture content in saline soil of 0-20 cm was 13.3% higher than that in slightly saline soil.Freezing and thawing made soil water and salt redistributed.The variation trend and amplitude of soil moisture and salinity in dif-ferent degrees of salinization soil during freezing and thawing periods were significant (P <0.05).