洞庭湖区,位于我省北部,属中亚热带向北亚热带过度的大陆性季风性湿润气候区,年平均气温16.9℃,年平均降雨量1277.8mm,年平均相对湿度78～80%。境内皆为河、湖冲积淤积平原,土层深厚,土质肥沃,但地下水位较高,PH 值较大,以南县为例,据土壤普查资料表明,PH 值大于 Dongting Lake region, located in the northern part of our province, is a subtropical northward subtropical humid monsoon climate zone, the annual average temperature of 16.9 ℃, the average annual rainfall of 1277.8mm, the average annual relative humidity of 78 to 80%. The territory of all rivers, alluvial silt plains, deep soil, fertile soil, but the higher the groundwater level, PH value is large, for example, the South County, according to soil census data show that the PH value is greater than