土壤风化速率的实验测定

利用模拟淋溶实验测定了中国几种土壤（砖红壤，赤红壤，红壤，黄棕壤和紫色土）的风化速率，并研究了土壤pH值和降水量对土壤风化速度的影响，结果表明，土壤的风化速度在pH≥4时随pH值的下降而显著增加，但是当pH值低于4时，风化速率却急剧下降，造成这种现象的原因可能是在低pH值时盐基阳离子和铝离子大量溶出，过高的产物浓度限制了风化反应的进行。土壤的风化速度与淋溶速率之间近似成线性关系。用淋溶液pH值和淋溶液量两个因素对实验结果进行了校正。

Experimental determination of soil weathering rate

Through simulated leaching experiment, weathering rates of several soils (including latosol, lateritic red earth, red earth, yellow brown soil and purplish soil) in China, as well as the effects of soil pH value and precipitation rate on soils weathering, were studied. During the experiment, the weathering rate increased with the leachant pH falling off to 4\^0, but decreased evidently when pH<4\^0 due to the high concentration of reaction products such as Al\+\{3+\} and base cation. In addition, the weathering rate decreased linearly with the reduction of percolation rate. The experimental results were adjusted by leachant pH and percolation rate.