Land Use Types and Topographical Attributes Affect the Soil Physicochemical Properties and Micronutrient Status in a Typical Watershed on the Loess Plateau

ABSTRACT Soil physicochemical properties and micronutrient content are critical for assessing soil quality and plant growth. However, their variation across land use types and topographical features remains unclear. We examined the effects of slope aspect, slope position and land use on the soil characteristics in the Wangmaogou watershed on China's Loess Plateau. Soil samples were collected from sunny and shady slopes at summit, upper, mid and foot slope positions across four land use types (slope farmland, terraced fields, woodland and grassland). Slope aspect significantly affected soil silt content, total Mn and available Zn ( p < 0.01). Slope position significantly influenced soil silt content, total Cu and available Fe ( p < 0.01). Land use type significantly affected total Mn and available Zn content ( p < 0.01). Principal component analysis revealed notable differences in soil physicochemical properties and micronutrient content between woodlands and grasslands compared with slope farmland and terraced fields, between upper slope and foot slope positions. Redundancy analysis indicated that the first and second axes explained 77.72% and 18.50% of the variance in soil physicochemical properties and micronutrient content, respectively. Slope position, land use type and slope aspect contributed to 67.10%, 18.20% and 14.70% of the observed variation, respectively. Slope position emerged as the primary factor influencing changes in soil physicochemical properties and micronutrient content. These findings provide valuable insights for soil and vegetation restoration across different topographical attributes of the Loess Plateau in China.