重庆地区20年间紫色土酸化研究

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

以酸沉降危害严重的重庆市为研究区域,对其主要农业土壤———紫色土进行大面积土壤酸化调查,与20世纪80年代中期重庆市土壤普查的保留样品进行对比分析研究,以探讨近20年来酸沉降对紫色土的危害程度。结果表明:与20世纪80年代中期比较,目前重庆市农用地和蔬菜地中的石灰性紫色土减少,而酸性和强酸性紫色土增加;同时,农用地的土壤交换性酸和交换性铝均有一定程度的上升。证实了在近20年的酸沉降影响下,重庆市大部分紫色土已发生酸化,且酸化程度日益加深。

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.