A Study of the Acidification of Purple Soil in Chongqing in Recent Two Decades

In this paper, the purple soil in Chongqing, which was serious damaged by acid precipitation,is selected as the study objective. The current status of soil acidification is investigated in this study. The investigation of soil acidification based on the data of the soil investigation of Chongqing in 1980's. At the same time, the representative soil samples from Chongqing are collected to analyses the pH, exchangeable acidity, exchangeable aluminum and acidic buffering ability. Changes in soil acidity of Chongqing in recent two decades are known by comparing the data of two stages. The status of purple soil acidification in Chongqing is showed by investigation. Compared with the 1980's, the alkaline purple soil of farms in Chongqing has decreased. However, the acidic purple soil has increased in some degree. The pH of soil decreases, but the exchangeable acidity and exchangeable aluminum had increases. It can be predicted that the area of soil acidification is expanding trend and that the degrees of soil acidification have a deepening trend.