1990 Fiscal Year Final Research Report Summary
Formation of the Optimum Mass Transfer System in Agricultural Land
| Project/Area Number |
62440017
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
農業土木
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| Research Institution | The University of Tokyo |
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Principal Investigator |
NAKANO Masashi The Univ. of Tokyo, Fac. of Agr., Professor, 農学部, 教授 (00011908)
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| Co-Investigator(Kenkyū-buntansha) |
KURATA Kenji The Univ. of Tokyo, Fac. of Agr., Assoc. Prof., 農学部, 助教授 (90161736)
TAKAKURA Tadashi The Univ. of Tokyo, Fac. of Agr., Prof., 農学部, 教授 (50011929)
SHIOZAWA Sho The Univ. of Tokyo, Fac. of Agr., Lecturer, 農学部, 助手 (80134154)
AMEMIYA Yuu The Univ. of Chiba, Fac. of Hort., Assoc. Prof., 園芸学部, 助教授 (40012041)
MIYAZAKI Tsuyoshi The Univ. of Tokyo, Fac. of Agr., Assoc. Prof., 農学部, 助教授 (00209892)
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| Project Period (FY) |
1987 – 1990
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| Keywords | water movement / solute movement / water clearing / soil erosion / solute accumulation / leaching / ion exchange / water flow on slope |
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| Research Abstract |
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
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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
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