南疆绿洲-荒漠过渡带土壤盐碱化分析

The Analysis of Soil Salinization in Oasis-Desert Transition Zone in Southern Xinjiang

该研究采用野外实地采样和实验室实验分析相结合的方法,对南疆泽普县金胡杨林、莎车县依盖尔其镇、麦盖提县叶尔羌河特大桥和巴楚县夏玛勒林场采样点0~60cm土壤样品进行分析。结果表明:(1)土壤各层pH值均值>8、盐离子以K+、SO_4^(2-)、Cl^-、Na^+、HCO_3^-为主,含盐量在1.409~6.953g/kg,土壤pH、电导率及盐离子随采样深度增加均有降低趋势,且其中电导率、SO_4^(2-)、Cl^-以及Ca^(2+)+Mg^(2+)与采样深度相关性较强,其他指标相关性不强。研究表明该地区土壤盐分离子在垂直方向变化有规律,在水平方向分布情况比较复杂;(2)南疆绿洲-荒漠过渡带土壤上层盐渍化程度不严重,盐分中碳酸盐和重碳酸盐最多,随着深度增加碳酸盐和重碳酸盐所占盐分比例先增大后变小。上层土样以苏打盐土为主,中层全为苏打盐渍化土,下层以纯苏打盐渍化土为主。Cl^-/SO_4^(2-)的值在0~1,表明在上层氯化物-硫酸盐盐渍化土为主,中下层以硫酸盐盐渍化土为主;(3)EC25与SO_4^(2-)、Cl^-、Na^+呈极显著正相关,在0~20cm层EC25除受SO_4^(2-)、Cl^-、Na^+影响外,也受CO_3^(2-)影响,在K+含量极低的情况下可能出现与K+显著负相关情况,但是EC25与总盐呈极显著正相关。

The methods of field sampling and laboratory analysis were used to analyze 0~60cm soil from sampling point of gold P.euphratica forest of Zepu County in Southern Xinjiang,Yigal Town of Shache County,Yarkant River Bridge of Mengaiti County,and Sharma forest farm of Bachu County. Results show average p H value of the soil layers is over 8. Salt ions include K＋,SO4^2-,Cl^-,Na^＋and HCO_3^-,he salt content is in 1.409g/kg~ 6.953g/kg. Soil p H,electrical conductivity and salt ions have decreased with the sampling depth increases,and the conductivity,SO4^2-,Cland Ca^2＋＋Mg^2＋are strong correlation with the sampling depth,he correlation between other indexes is not strong. The soil salt ions in the vertical direction show the law,in the distribution of horizontal direction is more complex;The degree of soil salinization in the ecotone between oasis and desert is not serious,Carbonate and bicarbonate in salt are the most. As the depth increases,he proportion of carbonate and bicarbonate increases firstly and then decreases.The upper soil is mainly sodic saline soil,he middle layer is soda saline soil,and lower soil is the primary of pure soda saline soil. Cl^-/SO4^2-value is between 0~1,revealing the upper is mainly chloride sulfate saline soil,he middle lower is mainly sulphate saline soil. EC25 and SO4^2-,Cl^-,Na^＋are significantly positively correlated in the 0~20cm layer,also affected by CO3^2-. It is significantly negatively correlated with K＋with low content,but show a significant positive correlation between EC25 and total salt.