Formation of the Optimum Mass Transfer System in Agricultural Land

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In order to make clear the optimum conditions of materials circulation in agricultural land, the coupling movement of water, solutes and micro-solids in soil were examined and analyzed.1. The works on solute transport : The four-method was newly devised to solute concentration in soil. The salt accumulation in soil by evaporation, the process of soil sodicification by groundwater containing salts, and the reclamation process of sodic soils by applying Calcium were systematically shown through much data. It was shown that the results could be analyzed by using a mathematical simultaneous-transport model considering ions exchange in soil.2. The works on micro-solids transport : The captured phenomena of micro-solids in soil were shown in the case which water containing the suspended clay particles infiltrated into soil. The data resulted in understanding the decreases of soil percolation and in understanding the mechanisms of water clearing by means of soil.3. The works on infiltration i … More nto layered soil : That the boundary lines between layers in soil made a characteristic flow in lower layer was shown, and the direction of flow was analyzed in two-dimensional planes.4. The works on water erosion : The physical properties of crusts formed under rainfall were observed and it was shown in details that the low permeability of crusts affected on the amount of eroded soil.5. The works on the others concerning living things : The method measuring the force and rate of plant root elongation was devised and the measurements were carried out. The relationships between the force and soil hardness were obtained as functions of water contents. The activities of microorganism in uplands were wxamined and it was shown that they affected on water infiltration into soil.On basis of the above results, the system of simultaneous movement of water, solute and solid particles was constructed as a mathematical model and published by the Tokyo University Press in order to make its utilization convenient. Less