Abstract
The soil-overturning properties is an important matter in the working results by rotary tillage, but the mesuring method is not still established in Japan. The purpose of this study is to obtain establishment of the mesuring method and the accurate ratio of soil displacement by rotary tillage. This paper deals with two methods calcurating the ratio of soil displacement.
In this experiment, we adopted the method to use the soil mixed kalium chloride (KCI), as electrical conductivity and concentration of solution of KCI were in proportion to each other. After the electrical conductivity of the soil which mixed two level's soils differing in electrical conductivity was mesured, we discussed on a hypothetical equation to calculate the electrical conductivity of the mixed soils. The deviation between mesured electrical conductivity and calculated one showed the range of -3.4-2.3%. However it is assumed that this degree of errors are practically admitted.
From application of the hypothetical equation, the two methods (simultaneous equations of three unknowns and conditional inequality) to obtain the ratio of soil displacement were derived. Mesuring the electrical conductivity of soils which were picked before and after rotary tillage, we can easily estimate by these methods the each ratio that a soil layer before tillage moved to the three layers after tillage.
The method by simultaneous equations of three unknowns must perform the experiment of three plots in which the mixture soil of KCI was put at each layer before rotary tillage. Moreover, this method needs to make the uniform conditions of the three experimental plots.
In case of the method by conditional inequality, the ratio of soil displacement is calculated with a certain range. Therefore if this range increases, the estimating inequality become useless. However, increasing the electrical conductivity of mixture soil of KCI, it is possible to decrease the range within 1%.
