在淋洗条件下土壤盐渍度的空间变异性

用6种不同含盐浓度的水分淋洗Tulare粘土,分层测定0-150cm土层的EC和Cl～-值,采用经典统计和半方差分析方法,分析了土壤剖面EC和Cl~-的分布特征、EC和Cl~-的相关性,以及72个取样点间的EC和Cl~-的空间连续性。

THE SPATIAL VARIABILITY OF SOIL SALINITY DURING LEACHING

It is clear from this paper results that: (1)The spatial structure of soilEC and C1~- during leaching at depths 1(0-30 cm), 2 (30-60 cm), 3 (60-90 cm),and 4 (90-120 cm) is affected more by salt concentration of the leaching water then bythe original properties of soil. The curves display cyclic behavior corresponding to thedistance between treatment replications. Depth 5 (120-150 cm) was more influenced bysoil properties than by surface application. (2) The spatial distributions of EC and Cl~-in the soil profiles of different treatments show that (a) the lower the concentration ofleaching water, the higher the efficiency of leaching and the lower the EC and C1~-concentration, listed by the efficiency of leaching, treatment 400 ppm>1500ppm>3000ppm; (b) high concentration of the leaching water will not leach salt from thesoil; rather it increases the salt load in the soil profile. Therefore, salt concentrationsgreater than 4500ppm will not improve this soil, but will result in increased salinity.(3)The spatial distribution of average values of EC and C1~- of 72 soil profilesdemonstrate the effect of leaching water on soil improvement. (4)there is a closecorrelation between EC and C1~- in the soil profile. (5)Spatial variability for samples isbest described by semivariogram analysis. Semivariogram of EC and C1~- for thisexperiment indicate that EC and Cl~- are spatially structured as the result of experimentaldesign, application methods and soil properties.