Abstract:
The soil quality under different land use types in the Benghe River Basin of the Yimeng mountainous region were evaluated by analyzing the soil physical and chemical properties, using the soil quality index (SQI) and the minimum data set (MDS) established by using the principal component analysis (PCA) method. The results showed that: (1)The soil physical properties changed significantly under different land use types. The lowest soil bulk density, the least sand content, the most clay content and higher soil moisture content was found in forest land, while the opposite trend was found in garden land. Cultivated land had higher soil bulk density, less sand and clay content, and the highest soil moisture content, while the opposite was for grassland. (2) Soil chemical properties differed significantly under different land use types. Soil pH values were grassland > forest land> cultivated land > garden land. Soil organic matter, total nitrogen, alkaline nitrogen and total potassium were high, while available phosphorus was low in forest land and grassland.Total phosphorus was lowest and available potassium was highest in forest land, and the opposite was in grassland.Soil organic matter, total nitrogen, alkaline nitrogen and total potassium were low in cultivated land and garden land, while total phosphorus and available phosphorus were high, and available potassium was high in cultivated land and lowest in garden land. Soil organic matter, total nitrogen and available potassium were relatively deficient in cultivated land and garden land in the study area. (3) The soil quality index of different land use types was SQI forest land (0.64) > SQI grassland (0.51) > SQI cultivated land (0.35) > SQI garden land (0.23), and the total soil nitrogen content was the key factor limiting the soil quality of cultivated land and garden land in the study area. (4) The minimum data set (MDS) consisting of soil bulk density, sand content, and total nitrogen content could replace the total data set (TDS) for soil quality evaluation in the study area.
