酸性硫酸盐土酸消长的水动力机制研究

以不同土壤湿度、不同干湿交替周期和原状土自然风干 8个处理进行酸性硫酸盐土 (简称ASS)室内模拟实验。通过对模拟过程内土壤pH、总硫化物性酸度和未氧化双氧水可氧化硫、交换性酸度、硫派生的实际酸度、KCl可提取硫等指标的动态变化过程的跟踪测定和分析显示 ,土壤水分条件是制约ASS酸度及酸形态转化的重要动力机制 ,可导致ASS酸度和酸形态的有规律变化。ASS产酸量和洗酸量受干湿交替周期制约

HYDRODYNAMIC MECHANISM ON THE CHANGE OF DIFFERENT FORMS OF A CID IN ACID SULFATE SOIL

The simulation, aimed to detect the quantitative impact of soil water conditions on the acidification of acid sulfate soil (ASS), was held with 8 treatments. Th e results indicated that water was an important dynamic mechanism on the change of different forms of acid such as exchangeable H , exchangeable Al 3 , t otal exchangeable acidity, total sulfuric acidity, total actual acidity, and tot al potential acidity in ASS. As a result, the changes of water condition would r egulate the change of soil acid content. The results also showed that wet but no t inundated or over dried ASS was benefit to the formation of exchangeable acidi ty and total actual acidity. In the treatments of alternation between inundated and drained off, significant acidification happened during the period of aeratio n drying after drainage, especially at the surface layer of the soil columns. Du ring the inundated periods, the acid forms were relatively stable. The acidity o f ASS was discharged in the drainage processes, and the more frequent the alterm ation was, the larger the total accumulative output and discharge of acidity was .