论文部分内容阅读
采集华北平原潮土样品对其酸度特征和酸化敏感性进行了初步探讨.结果显示,过量施用氮肥导致的硝酸盐积累是华北平原潮土pH值下降的重要原因,硝酸根与土壤pH值呈显著负相关.碳酸钙溶解是当前潮土缓冲酸化的主要过程,决定着潮土对外界酸输入的响应方式和敏感程度.随着酸输入量的增加,低碳酸钙土壤的pH值迅速下降,但高碳酸钙的石灰性潮土对酸输入不敏感.潮土酸化的敏感性主要决定于碳酸钙含量,临界缓冲容量、酸缓冲强度及pH缓冲强度等土壤敏感性指标均与碳酸钙含量呈显著正相关.初步分析显示,在长期集约化耕作的影响下低碳酸钙潮土存在pH值急剧下降的风险.建立和完善适合华北平原潮土及其它中-碱性土壤的酸化敏感性评价方法和指标体系已成为对潮土酸化进行科学调控的迫切需要.
The results showed that nitrate accumulation caused by over-application of nitrogen fertilizer was the important reason for the decrease of pH value in the alluvial soil of the North China Plain, and the pH value of nitrate and soil was significant Negative correlation.The dissolution of calcium carbonate is the main process of buffer acidification in the current, which determines the response and sensitivity of the soil to the external acid input.With the increase of acid input, the pH value of low calcium carbonate soil decreased rapidly, Calcareous alluvial soil with high calcium carbonate is not sensitive to acid input.The sensitivities of soil acidification mainly depend on the soil calcium carbonate content, critical buffer capacity, acid buffer strength and pH buffer strength Positive correlation.The preliminary analysis shows that under the influence of long-term intensified tillage, there is a risk of pH value falling sharply in the fluvo-aquic soil.Establishing and perfecting the acidification sensitivity evaluation method suitable for the alluvium and other medium-alkaline soils in the North China Plain and The indicator system has become an urgent need for scientific regulation of acidification of the tide soil.