Effects Of Land Use Patterns On Soil Clay Mineral Composition And Colloid Surface Charge

Soil is the main base of agricultural production.Clay mineral is the main component of soil.We can understand soil fertility and classification through soil clay mineral composition.The colloid surface charge is the basis of soil with fertility.The change of soil clay mineral and colloid surface charge would affect the quality of soil.In recent years,the influential factors of soil clay mineral and colloid surface charge have been reported,but researches about effect of land use patterns on soil clay mineral composition and colloid surface charge were unclear.So the soil of wasteland,woodland and farmland were selected as research objects.X-ray diffraction spectroscopy and Mehlich method were used to study effects of land use patterns on soil clay mineral composition and colloid surface charge,the results were as follows:Under using of the CK farmland,wasteland and woodland,the weathering of soil mineral paticles decreased,but contents of chlorite increased.The contents of illite in the CK farmland was higher than wasteland and woodland.The contents of the I/S mixture in the woodland was higher than wasteland and CK farmland.Compared with the soil clay minerals in the CK farmland,the contents of illite and kaolinite in the corn land was lower than CK farmland,and contents of chlorite was higher than CK farmland.Land use patterns on soil could lead to soil pH,exchangeable H +,exchangeable Al3 +,exchangeable acid,organic matter and cation exchange capacity change,then affected contents of kaolinite,chlorite,and montmorillonite in soil clay mineral.Farmland with no fertilization would promote weathering and differentiation of clay mineral,and long-term fertilization would inhibit the weathering and differentiation of clay mineral.At the same time,root decay and microbial decomposition of woodland would benefit weathering and differentiation of illite.The CEC8.2 of land use patterns on soil colloid influenced by organic matter,and it was increased as the increasing of the organic matter value.The CEC8.2 of soil colloid was influenced by soil acidity.when soil was tending to acidification would lead to the amount of negative charge and the base ions of soil surface adsorption reduce,after soil base saturation was reducing,it caused the deterioration of soil quality.The CECp of land use patterns on soil colloid was not affected by organic matter and the surrounding environment.Organic matter was the main source of variable charge in the soil.The variable negative charge of woodland soil colloid was highest among the land use patterns.The organic matter content of corn land was reduced after fertilizing,which lead to the variable negative charge of colloid decrease.The CECm of land use patterns on soil colloid regularity was not obvious,it was not affected by organic matter,pH and soil acidity.The AEC of land use patterns on soil colloid was decreased as the increasing of the organic matter value.The net negative charge amount of land use patterns on soil was decreased as the decreasing of the organic matter and pH.The net negative charge amount of soil colloid will gradually reduce when soil continuously tending to acidification.To sum up,the incorrect land use would cause changes of soil clay mineral content and colloid surface charge,then affect the quality of the soil and change the soil environment.