不同利用方式对土壤黏粒矿物组成的影响

Effects of Land Use Patterns on Soil Clay Mineral Composition

以荒地、林地、耕地土壤为研究对象,采用X射线衍射(XRD)分析方法,研究了不同利用方式对土壤黏粒矿物组成的影响。结果表明:耕地(ck)、荒地、林地利用的土壤黏粒矿物的风化依次减弱,绿泥石的含量依次升高;耕地(ck)的土壤黏粒中伊利石的含量高于荒地和林地,为57.61%;林地的土壤黏粒中I/S混层矿物含量高于荒地和耕地(ck),为47.92%;与耕地(ck)的土壤黏粒矿物相比,玉米地的伊利石和高岭石含量低于耕地(ck),分别为38.66%、5.93%,绿泥石含量高于耕地(ck),为4.92%;土壤的不同利用方式可导致土壤pH、交换性酸、交换性H^+、交换性Al^(3+)、有机质和阳离子交换量发生变化,进而影响土壤黏粒矿物中高岭石和绿泥石含量的变化。土壤只耕作不施肥有利于黏粒矿物的风化转化,长期施肥抑制黏粒矿物的风化转化,林地根系的腐解和微生物的分解作用有利于伊利石的风化转化。

The soil of wasteland, woodland and farmland was selected as research object, and X-ray diffraction spectroscopy was used to study effects of land use patterns on soil clay mineral composition. The results showed that under the use of the ck farmland, wasteland and woodland, the weathering of soil mineral particles decreased, but content of chlorite increased. The content of illite(57.61%) in the ck farmland was higher than in wasteland and woodland. The content of I/S mixture(47.92%) in the woodland was higher than in wasteland and ck farmland. Compared with soil clay minerals in the ck farmland, the content of illite and kaolinite(38.66% and 5.93%) in the corn land was lower than in ck farmland, and the content of chlorite(4.92%) was higher than in ck farmland. Land use patterns could lead to changes of soil pH, exchangeable acid, exchangeable H +, exchangeable Al3 +, organic matter and cation exchange capacity, then affected content of kaolinite and chlorite in soil clay minerals. Farmland with no fertilization would promote the weathering and differentiation of clay minerals, and soil after fertilization would inhibit the weathering and differentiation of clay minerals. At the same time, root decay and microbial decomposition of woodland would benefit weathering and differentiation of illite.