塔里木河上游棉区不同类型盐土阳离子交换量分布特征及影响因素

Distribution Characteristics and Influencing Factors of Cation Exchange Capacity of Different Types of Saline Soil in Cotton Planting Region of Upper Reach of Tarim River

【目的】研究塔里木河上游棉区不同类型盐土CEC的分布状况及影响因素。了解不同类型盐土土壤特性及肥力状况,为新疆南疆干旱区盐土改良利用提供理论依据。【方法】以阿拉尔绿洲草甸盐土(MeS)、沼泽盐土(MaS)、残余盐土(ReS)、洪积盐土(PrS)、棕漠林盐土(DeS)5种典型盐土为对象,研究该流域不同类型盐土阳离子交换量(CEC)的剖面分布规律,分析盐土CEC的影响因素,并利用灰色关联法对盐土CEC与土壤理化性质之间的关系进行了量化。【结果】该区盐土CEC在2.02~25.54 cmol/kg,平均值为12.39 cmol/kg,CEC随剖面深度的变化规律各类型盐土有所不同,不同类型盐土CEC大小依次为MeS>ReS>DeS>PrS>MaS。粘粒是干旱区盐土CEC的主要来源;pH、CaCO3、盐基总量(TEB)和碱化度(BSP)与盐土CEC呈极显著正相关,是盐土CEC的主要影响因素,其中CaCO3对盐土CEC的贡献不容忽视;盐土有机质(SOM)含量极低,对盐土CEC未表现出显著性影响;交换性钙饱和度(CaSP)、交换性镁饱和度(MgSP)及交换性钾饱和度(KSP)对盐土CEC有显著的抑制作用。【结论】塔里木河上游棉区不同类型盐土CEC有显著差异,不同类型盐土保肥、供肥及缓冲性能不同。pH、CaCO3、TEB和ESP是CEC主要贡献因子,SOM对盐土CEC无显著的影响。

【Objective】To find out the profile distribution rules and influencing factors under different types of saline soil CEC in cotton planting region of upper reach of Tarim River.【Method】Five typical salts of meadow solonchak(MeS),Marshy solonchak(MaS),Residual Solonchak(ReS),Proluvial Solonchak(PrS),and Desert solonchak(DeS)were studied and the relationship between CEC and soil physical and chemical properties was quantified by grey correlation method.【Results】The saline soil CEC in the profiles ranged from 2.02 to 25.54 cmol/kg and the average value was 12.39 cmol/kg.The variation of CEC with the depth of the profile varied with each type of saline soil.The MeS had the highest CEC,followed by the ReS,the DeS,the PrS and then the MaS.Clay particle(CL)was the main source of CEC in saline soil in arid areas.pH,CaCO 3,total exchangeable base cations content(TEB)and exchangeable sodium saturation percentage(ESP)were significantly positively correlated with the saline soil CEC,and were the main influencing factors of CEC in saline soil.The contribution of CaCO 3 to the saline soil CEC could not be ignored.The soil organic matter(SOM)content was very low and had no significant effect on the CEC of saline soil.Exchangeable calcium saturation percentage(CaSP),exchangeable magnesium saturation percentage(MgSP)and exchangeable potassium saturation percentage(KSP)had significant inhibitory effects on saline soil CEC.【Conclusion】The CEC of different types of saline soils in cotton planting region of the upper reach of the Tarim River is significantly different.The results show that different types of saline soils have different properties of fertilizer conservation,fertilizer supply and buffering.pH,CaCO 3,TEB and ESP is CEC main contribution factor.SOM has no significant effect on the CEC of saline soil.