Studies on Evaluation Method for Physical Properties of Soil after Jillage

(1)本文讨论了用对数正态Rosin-Rammler分布、Gaudin-Shuman分布和Weibull分布来近似块状粒径分布。在采用威布尔分布近似的情况下，通过改变其形状参数的取值，得到了满意的结果。(2)取样器直径的选择必须考虑土块的平均直径。在旋耕法的情况下，取样器的直径应在200毫米以上(1)利用氯化钾测定土壤电导率的变化，成功地评价了土壤的翻土率。(2)利用该方法检测了上切旋耕法与下切旋耕法的翻土差异。(3)耕后土壤向前移动25cm以上，向后移动50cm以上。

[1] Studies on clod size distribution (1) We discussed the approximation of the clod size distribution by log-normal Rosin-Rammler's, Gaudin-Shuman's and Weibull's distribution. In case of the approximation by Weibull's distribution, we obtained satisfactory results by means of changing the value of its shape parameter. (2) The diameter of sampler must be selected considering the average diameter of soil clod. In the case of rotary tillage, it is found that the diameter of sampler should be 200 mm on more.[2] Studies on evaluation about turning of soil (1) We succeeded in evaluating the turning percentage of soil by means of measuring the change of Ec (electric conductivity) using potassium chloride. (2) We detected the differenece of turning between up-cut rotary tillage and down-cut rotary tillage using the method. (3) The forward movement of soil after tillage is more than 25 cm and the backward one is more than 50cm.