Abstract:
Background Black soil area in eastern Mongolia is an important commercial grain base in Inner Mongolia Autonomous Region. Soil degradation seriously affects regional food security and sustainable use of black soil. To clarify the degradation status of sloping cropland is the premise of comprehensive management and improvement of black soil.
Methods Selected Moqi as the study area, sloping cropland as the research object, based on the soil measurement data, minimum data set, sequential Gaussian simulation, and mathematical statistics methods, we analyzed the spatial distribution of the degradation degree of sloping cropland in this region, the forms and the driving factors of degradation.
Results 1) The minimum data set of assessment system on soil degradation degree included: Soil organic matter, A-horizon thickness, large water-stable aggregate, pH, slope, and ridge-slope angle. 2) The soil degradation index of sloping cropland in this region ranges from 0.0811-0.799 8. The slightly degraded and moderately degraded sloping cropland accounted for 83% of the total sloping cropland area. 3) The correlation between soil degradation index and A-horizon thickness was the highest (P < 0.01), were positively correlated with slope and ridge-slope angle (P < 0.05), the correlation coefficient between slope and ridge-slope angle was 0.356 (P < 0.05).
Conclusions The degradation degree of sloping cropland gradually increased from northeast to southwest in study area, mainly with slightly degraded and moderately degraded sloping cropland. The loss of A-horizon layer and the reduction of cultivated area were primary characters. The interaction between slope and ridge-slope angle might be the driving factors leading to the degradation of sloping cropland. The results can provide data support for the prevention and control of sloping cropland degradation in the black soil area of eastern Inner Mongolia.