Effects of land uses and environmental factors on soil quality variation in the hilly Loess Plateau region, China

摘要

Study of soil quality variation and its affecting factors will have implication on understanding the essence of soil properties variation as well as proper evaluating and managing soil quality. In this paper spatial variation of soil quality indicators and the influence of landuse types and environmental factors on the variation at a regional scale of 700km2 in the central of the hilly Loess Plateau region, were analyzed using typical statistic method. The results demonstrated that there was a big difference of spatial variation among different soil quality indicators. Soil pH, structure coefficient, specific gravity, bulk density, total porosity, capillary porosity and catalase showed weak variability; soil nutrient (NPK) content, CaCO3 content, cation exchange capacity (CEC), clay content, micro-aggregate mean weight diameter (MICMWD), aggregate mean weight diameter (MWD), cohesion, water stable aggregates, respiration intensity, invertase, phosphatase, and microbial carbon and nitrogen showed medium variability; soil labile organic carbon, phosphorus, anti-scourability, infiltration coefficient and soil urease showed a strong variability. Variability of the dynamic soil quality indicators, including soil organic matter, nitrogen content, water stable aggregates, infiltration coefficient, microbial carbon and nitrogen, phosphatase and respiration intensity was dominated mainly by landuse types. For those inherent soil quality indicators of weak variability, including CaCO3, total phosphorus, total potassium, CEC, texture and specific gravity, their variability came mainly from differences in environmental factors such as the terrain. As a dominant factor of soil quality variability, landuse types could explain 97% of the variability of soil quality indicators on the hilly Loess Plateau. Full consideration to landuse types and environmental factors such as differences in terrain should be given for soil quality evaluation in the hilly Loess Plateau region.