Establishment of a restoration method of salt-damaged farmlands for technology transfer to developing countries

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07943
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Rural environmental engineering/Planning
• Research Institution: Tottori University
• Principal Investigator: INOSAKO Koji 鳥取大学, 農学部, 教授 (60243383)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 除塩 / 暗渠 / リーチング

Outline of Final Research Achievements

The objective of this study was to clarify the desalinization process of a reasonable underdrainage system using only rice husk as a main drain (RHUS) in salt-affected fields and to establish the restoration method of the farmlands for technology transfer to developing countries. Small model experiments and three-dimensional numerical experiments in field scales were conducted in this study. The results were summarized as follows;
1) the size of the outlet of rice husk drains (RHD) did not affect the drainage capacity of the system, 2) he amount of water discharged from the outlet increased when the width of the RHD narrows, 3) the RHD accelerated desalinization of a tillage layer by working as bypass of salt water movement from the tillage layer to lower subsoil, 4)It is small that the effect of the gradient of the RHD on the increase of the amount of discharged saline water from the outlet, 5) The RHUS was remarkably effective only for the desalinization of tillage layers.

Free Research Field

水土環境保全学

Academic Significance and Societal Importance of the Research Achievements

世界の灌漑農地の多くで塩害が発生している．塩害農地の修復法で最も効果的なのはリーチングであるが，その効果を適切に発揮するには農地の排水能を高める必要がある．そのためには暗渠の敷設が欠かせないが，経済的な余裕のない開発途上国では高価な暗渠資材は利用できず，十分な排水対策がとられていない．
本研究では，開発途上国で利用可能な安価な籾殻暗渠システムに着目し，模型実験と数値実験から本システムの除塩過程を明らかにした．また，実スケール規模の3次元数値実験の結果からシステムパラメータが除塩効果にもたらす影響を明らかにした．このことは，開発途上国への技術移転にとって有益な設計情報を提供するものといえる．