运用常规统计学和典范对应分析方法,对干旱区盐渍土土壤全盐量(TS)、盐分离子组成、碱化度(ESP)、pH、电导率(EC)的空间分布特征进行了分析。结果表明,该区土壤为重度至轻度盐化,不同层次土壤中,Na^+与Cl^-、Ca^2+与Mg^2+保持较好的关联性。TS的空间分布,在0~50cm全剖面上主要受控于Cl^-、HCO3^-和Na^+离子;分层与全剖面的情况略有不同,Cl^-、Na^+在各个土层仍为主要控制离子。ESP在全剖面上其空间分布受环境因子的影响较小,0—10cm土层主要受Na^+与Cl^-离子的制约;10—30cm土层内主要受HCO3^-离子的制约;30~50cm土层未表现控制因子。pH在全剖面上受盐分离子的影响较小,分布较为均匀,表层受离子影响很小,在10~30cm、30~50cm土层内受HCO3^-离子的影响微弱。EC在全剖面上的空间分布受控于Ca^2+、Mg^2+离子,30—50cm土层主要受K^+离子的控制,其他土层与全剖面相同。
Analysis of characteristics of spatial distributions of total salt content (TS) , ion composition, exchangea- ble sodium percentage (ESP) , pH value and electrical conductivity (EC) of salt-affected soils in the Arid Area was con- ducted, using conventional statistics and canonical correspondence analysis. Results show that ( 1 ) the soils in the region are heavily to slightly alkalized, e. g. heavy in topsoil ( 0 - 10 cm ) and slight in bottom ( 30 - 50 cm ) ;(2) close correlation exists between Na^+ and Cl^- , and between Ca^+ and Mg^2+ in all soil layers; (3) Cl- , HCO3^- and Na^+ are the main factors controlling spatial distribution of soil total salt throughout the whole profile ( 0 - 50 cm ) , which though varies slightly from layer to layer, where Na + and Cl^- remain to main factors ; (4) the spatial distribution of ESP in the profile is less affected by environmental factors, however, it is restricted mainly by Na^+ and Cl^- in the 0 - 10cm soil layer, by HCO/ in the 10 -30 cm soil layer, and by none in the 30 - 50 cm soil layer; (5) pH is quite evenly distributed throughout the profile and only slightly affected by salt ions, that is, it is very slightly affected by ions in the 0 - 10 cm soil layer, and only weakly influenced by HCO3- in thel0 -30 cm and 30 - 50 cm soil layers; (6) the spatial distribution of EC is controlled by Ca^2+ and Mg^2+ throughout the whole profile, except in the 30 - 50 cm soil layer where K^+ is the dominant