Evaluation of Land Quality Under Different Land Use Patterns on the Qingshuihe Plain in China

ABSTRACT

Land quality assessment plays a significant role in ensuring food security, maintaining ecological balance, and promoting sustainable agricultural development, especially in environmentally vulnerable areas. Taking the Qingshuihe Plain in Ningxia as the study area, this research constructed a land quality evaluation system adapted to the characteristics of the semi‐arid region of the Loess Plateau. While soil quality specifically refers to the capacity of a soil to function within ecosystem boundaries, land quality is a broader concept that integrates soil properties with topography, climate, and vegetation status, and systematically analysed land quality conditions and their differences under various land use types. Through principal component analysis, Pearson correlation analysis, and common factor variance calculation, Minimum Data Sets (MDS) were screened and constructed for four land use types: grassland, dry farmland, forestland, and irrigated land. Results showed that: (1) Soil properties, topography, and ecological status varied significantly across land use types. Irrigated land had higher available and total nutrient content, grassland and forestland had higher organic matter and nitrogen content, while dry farmland fell between these two groups; (2) The MDS composition for each land use type showed distinct specificity. The grassland MDS included 8 indicators: SOM, Zn, NDBSI, Cr, Elev, AP, AK, and WET; dry farmland MDS included 5 indicators: Ni, SOM, TSC, NDVI, and Elev; forestland MDS included 4 indicators: Zn, AHN, TP, and NDBSI; irrigated land MDS included 5 indicators: Zn, TN, NDBSI, pH, and Slope; (3) The Land Quality Index based on MDS (LQI‐MDS) showed a significant positive correlation with the Land Quality Index based on the total data set (LQI‐TDS), validating the reliability of the MDS; (4) The average LQI‐MDS values for the four land use types ranked as follows: irrigated land (0.539) > dry farmland (0.496) > forestland (0.340) > grassland (0.309), reflecting the close relationship between human management intensity and land quality. The research results indicate that a differentiated land quality evaluation system adapted to regional characteristics can effectively characterise land quality conditions under different land use types in the loess region, providing a scientific basis for sustainable management of regional land resources and ecological environmental protection.