四川省万源市土壤pH值测定及土壤酸碱度分析

Determination and Analysis on the pH of Soil in Wanyuan City of Sichuan Province

[目的]讨论不同水土比例对土壤pH值测定的影响，分析万源市土壤的酸碱度。[方法]从四川省万源市的种植土壤中采集土样并制备成湿性土样和干性土样，采用酸度计测定法分别测定其pH值。[结果]当水土比例在2．5：1～5：1时，pH值的变化比较明显。大部分土壤样品干性土样的pH值比湿性土样的高，但湿性土样的pH值变化比于性土样更明显。万源市土壤多为中酸性土壤，其pH值在4．9～7．8，当水土比例为1：1-5：1时，对测定结果的影响不大；酸性土壤主要分布在中部、西部、西北角和东南部，东北部也有零星分布，其pH值在4．9～5．5，pH值最低点在西部地区；中性土壤主要集中在西南部，其pH值在6．5～7．5。pH值最高点在西南部。[结论]土壤pH值随水土比例的增大逐渐升高，万源市土壤主要为中酸性土壤。

[ Objective ] The aim of the study was to discuss the influences of different water-soil ratios on determining the pH values of soil and analyze the pH of soil in Wanyuan City. [ Method ] The soil samples were collected from the planting soil in Wanyuan City of Sichuan Province and made into wet and dry soil samples, their pH values were determined by aeidimeter measuration resp. [ Result] When the watersoil ratio was between 2.5：1 and 5：1, the change of pH values was relatively obvious. The pH values of dry soil samples of most soil samples were higher than that of their wet soil samples, but the change of pH values of wet soil samples was more obvious than that of dry soil samples. Most soil in Wanyuan City was intermediate-acidic soil, its pH value was between 4.9 and 7.8. When the water-soil ratio was 1：1 -5：1, its influence on determination results was little. The acidic soil was mainly distributed in the central, west, northwest-corner and southeast and there were fragmentary places distributed in the northeast, its pH value was between 4.9 and 5.5. The site with lowest pH value was in the western region. The neutral soil was mainly centralized in the southwest and its pH value was between 6.5 and 7.5. The site with highest pH value was in the southwest. [ Conclusion] As the water-soil ratio was increased, the pH value of soil was increased gradually. Most soil in Wanyuan City was intermediate-acidic soil.