喀斯特山区土地利用方式对土壤质量的影响.

[Objective] This purpose of the article was to prove effects of land use types on soil quality, and to offer reference for ecological civilization construction and sustainable development of social economy in fragile karst environment of western Guizhou. [Method] Five different land use types (farmland, abandoned land, natural grassland, artificial grassland and forest land)were researched to explore their influences on soil quality by means of field experiments and laboratory analysis. [Result] The different land use types resulted in significant differences in soil bulk density and porosity. Hie forest land had the best soil bulk density and porosity, and the farmland had the worst. File value of soil field moisture capacity of five land use types ranged from 34.01 % to 48. 38 % which resulted in a significant difference. The pH values of five land use types ranged from 4. 59 to 5.53, and the farmland had the minimum of pH value. The soil cation exchange capacity of forest land, artificial grassland and abandoned land was higher than that of natural grassland and farmland. The descending order of five land use types according to the soil organic matter content (28.4-76. 27 g/kg) was forest land, natural grassland, artificial grassland, farmland and old field. The contents of total N, total P, available N and available P were the highest in farmland. The available indexes of total K and available K were less than 0.9 in difference land use types, and there was significant different among them. The soil available Cu and available Zn index of the five land use types ranged from 6. 50 to 14. 65. Based on the comprehensive indices of soil nutrients, five land use types were listed in descending order; forest land, natural grassland, artificial grassland, abandoned land and cropland. The comprehensive index of forest was about 1.68 times to that of farmland. [Conclusion] Soil quality of grassland and forest land was better than that of farmland and abandoned land. The conclusion of this paper was to provide the basis for rational development and utilization of land resources. [ABSTRACT FROM AUTHOR]