保护地土壤酸缓冲性能研究

在辽宁省沈阳市于洪地区采集保护地土壤样品，用模拟的方法绘制酸缓冲曲线，测定酸害容量及酸害强度，对土壤的酸缓冲性能进行深入研究，探讨土壤的酸缓冲性能随保护地栽培年限的变化，结果表明：保护地种植年限越长，土壤pH值越低，土壤酸害容量（达到植物受害pH值所需要的酸）越小；达到植物受害pH值时所需要的酸越少，越容易对作物产生酸害。不同种植年限保护地土壤和露地土壤的酸缓冲曲线相似，但斜率各不相同。露地土壤酸缓冲曲线斜率绝对值最大，加入等量酸后pH下降幅度最大，即土壤酸害强度（土壤对酸的承受能力）越小；而作为保护地种植年限越久，酸缓冲性能曲线斜率绝对值最小，加入等量酸后土壤pH下降的越慢，土壤酸害强度越大。土壤酸害强度与有机质含量及阳离子交换量均呈极显著的正相关关系。

Study on Soil Acid-buffer Ability in Protected Fields

Soil samples were collected from protected fields in Yuhong District of Shenyang, Liaoning Province, China, for determination of soil acid-buffer curve,soil acid-damage intensity,and soil acid-damage capacity,and further analysis of variation of the soil acid-buffer ability with planting years in protected field. Results show:The longer the planting years in protected field, the lower the pH and soil acid-damage capacity, the less content of acid to reach the point of crops injured, the easier injured.The soil acid-buffer curve of protected fields under different planting years and open fields were approximately similar,but not in slope.The absolute value of slope of soil acid-buffer curve was the greatest in open fields.In the case of equal acid joining, a bigger drop in soil pH.That is to say, soil acid-damage intensity was small.With replanting time prolonging, the absolute value of slope of soil acid-buffer curve was continuing decrease in protected field, that is to say, the acid bearing capacity of soil was keep decreasing. In the case of equal acid joining, a smaller drop in soil pH.That is to say, soil acid-damage intensity was big. There is a significant positive correlation between soil acid-damage intensity and the content of OM and CEC.