土壤崩解速率的一种修正方法

A New Modified Method for Calculation of Soil Disintegration Rate

为了获得更为准确的土壤崩解速率测定及计算方法,以便客观评价土壤侵蚀程度,借助子洲县坡耕地原状土壤样品,通过土块在水中受力分析,对比了拉力计方法和修正拉力计方法计算的土壤崩解速率结果。结果表明,拉力计方法测定土壤崩解速率中土壤自身含水量对崩解过程有重要的影响。修正拉力计算法所得的土壤崩解速率与已有报道更为吻合,其变异性较未修正前有所减小。因此,建议在土壤崩解速率测定和计算应按以下步骤:(1)利用方形环刀在野外取原状土样并用塑料薄膜密封;(2)将土样带回实验室称重,垫上滤纸,用浅层水盘自下而上浸润土壤,直至土壤饱和;(3)将饱和的土样放置在一铁架台上去除重力水后再次称重;(4)轻轻移开方形环刀,将土样放置在拉力计的吊盘网板上测定;(5)计算需乘以校正系数k。

To obtain a more accurate calculation method of soil disintegration rate and evaluate soil erosion de- gree correctly. In the present paper, two calculation methods of soil disintegration rate are compared by focu- sing on the force analysis of soil sample in static water. The soil samples were taken from a slope farmland in Zizhou. Results showed that soil moisture content of samples has the significant influence on the process of disintegration when using the method of tension meter to determine the soil disintegration rate. The results of soil disintegration rate under the method of modified tension meter are in accordance with the theories that have been reported and the variability also reduces to some extent. The dynamic changes of buoyancy should be taken into account when calculating soil disintegration rate. Thus, it suggests that soil disintegration rate test should follow steps such as： （1） collecting undisturbed soil sample with plastic film sealing using the square-ring knife; （2） bringing soil sample back to laboratory, weighing soil sample, and matting the filter paper, then, putginf it in a plate with shallow water infiltration of soil from bottom to top, until the soil was saturated; （3） placing saturated soil samples in a hob on stage again after removing gravity water, and weig- hing soil sample again; （4） removing the square-ring knife gently, putting soil sample in the stage of the ten sion gauge sheet; （5） its calculation should be multiplied by the correction coefficient of k.