Multi-Scenario Contrasts in the Acidification Rate of Red Soil Dry Land in the Jitai Basin Based on Nutrient Management

The expansion of intensive agriculture has made soil acidification a key constraint on global agricultural productivity. Thus, comparing acidification rates under alternative management scenarios in current soil conditions and formulating regional governance plans accordingly are critical for ensuring food security. In this study, we systematically investigated red soil dry land in the Jitai Basin, quantified acidification rates via nutrient balance, and compared soil acidification rates under multiple nutrient-management scenarios evaluated in present soil conditions. The results show the following: Crop removal and nitrogen fertilizer input are the main driving factors that lead to the acidification of red soil dry land. The overuse of nitrogen fertilizer accelerates soil acidification. Regular scattering of lime is the most effective scenario for alleviating acidification. The total nitrogen, soil organic matter, cation exchange capacity, soil pH and soil type dominate the spatial distribution of the soil acidification rate. The total soil acidification rate and the actual acidification rate show a concentric-ring pattern, with high rates in the center and at the periphery and lower rates in the intermediate ring, while the potential soil acidification rate shows a gradient difference of “high in the west and low in the east”. By integrating multiple scenarios, the study area is divided into four levels of acidification control zones. It is suggested that, in future treatment of acidification in red soil dry land, fertilization management should be optimized and the rate at which the residual part of the crop harvest is returned to the field should be appropriately increased. The strategy of sprinkling lime can be adopted for areas with severe acidification.