湖北降水中的硫及其对农田生态的影响

Sulfur Content in Rainfall and its Effects on the Farmland Ecosystem in Hubei Province

在湖北兴山、当阳、郧县、襄樊、沙市、孝昌、武汉西郊和湖大、崇阳、罗田等 1 0个地点 ,自 1 996年 1月至 1 998年 6月按季度收集降水样品 ,测定硫含量。研究表明各地降水中SO42 - 浓度年均值及降水对农田的供硫量逐年增大 ;绝大多数地点每年 4季度至次年 1季度降水总硫量高于当年 2、3季度降水总硫量 ,因而对越冬作物影响明显超过对夏季作物影响。由于多数地点土壤持硫能力低 ,土壤有效硫不足 ,故降水中的硫可对作物带来有利的生态影响。然而 ,在降水供硫量大的鄂东南棕红壤酸性土壤地区 ,酸雨可能是促使土壤更酸和产生其他环境生态问题的潜在威胁。

Samples of rainfall Were seasonally collected from 10 locations in Hubei Province (Xingshan, Dangyang, Yunxian, Xangfan, Shashi, Xiaochang, Western suburb of Wuhan, Hubei University, Congyang ,Luotian)during January, 1996-June, 1998. All samples were analyzed for sulfur content .The result showed that SO 4 2- concentration in rainfall had increased year after year. Total contents of sulfur in most rainfall samples collected during October-March were higher than those collected during April-September. Therefore, effects of sulfur in rainfall on winter crops surpassed that on summer crops. Because sulfur content in soils was low at most sampling stations and the available sulfur was inefficient, sulfur in rainfall was beneficial to crops. The acid rain, however, is very possible to result in a further acidulation for the brown red soil in the eastern-southern Hubei Province, and the other concerned eco-environment problems could be induced by soil acidulation either.