Distribution of Soil pH and Its Relationships with Soil Nutrients in Bijie Tobacco-growing Area
毕节烟区土壤pH值分布状况及与土壤养分的关系

Distribution of soil pH and its relationship with soil nutrient contents were analyzed in tobacco-growing areas of Bijie in Guizhou Province. The results showed that mean value of soil pH was 6.39 with a variation coefficient of 11.87%. About 44.83% of the soil samples was within pH of 5.5-6.5, most suitable for the cultivation of high quality tobacco. The percentage of soil samples with pH 5.5-6.5 in total samples was in the following order: Jinsha County (67.44%)>Zhijin County (64.29%)> Dafang County (54.84%)>Qixingguan District (47.54%)>Qianxi County (36.59%)>Weining County (35.19%)>Hezhang County (24.24%)>Nayong County (15.38%). Soil pH of different soil types was in the following order: lime soil>purple soil>alluvial soil>yellow soil>yellow brown soil. There was a highly significant positive correlation between soil pH and total nitrogen, and a significantly positive correlation to available boron and zinc. However there were highly significant negative correlation between soil pH and ammonium nitrogen, available manganese and iron in Bijie Tobacco-growing areas. The contents of soil total nitrogen, available sulfur, available copper, available manganese and available iron were rich, but the contents of total phosphorus, available boron and water soluble chlorine were low or very low.