Abstract: Soil acidification was posing a significant threat to agricultural production and ecological balance in China. In Hubei Province, due to the influence of topography, climate, and human activities, the soil’s capacity to hold nutrients and convert them into absorbable forms has been weakened, consequently affecting crop yields and quality. To investigate the biochemical impacts of soil acidification on agricultural land and crops, the soil pH across various regions of Hubei Province from 2021 to 2023 was monitored. The results revealed that the southwestern and southern regions experienced the most severe acidification, while the northwestern region exhibited the fastest acidification rate. Two representative areas were selected for systematic analysis of six key indicators: pH, cation exchange capacity, total exchangeable bases, total phosphorus, total aluminum, and available phosphorus. The experiments demonstrated that soil acidification restricted the exchange ability of base cations, leading to soil compaction and impoverishment. Simultaneously, it inhibited the transformation of phosphorus into available forms, resulting in low nutrient use efficiency. If left uncontrolled, this would push the land into a vicious cycle of “acidification-reduced yield-increased fertilizer application-further acidification”.

Key words: soil acidification, cation exchange capacity, total exchangeable bases, phosphorus, aluminum, chemical effects, ecological effects