Bio-engineering by Polder System on Saline Soil in Thailand

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A study was conducted to examine a method of sustainable biological production by introducing the Polder System. The mainly purpose of the study is to develop a sustainable agriculture by cearting integrated biological production system which comprises of some components such as introduction of drought resistance and salt tolerance plant, cash crops cultivation, improvement of soil and water environment, surface soil conservation, small animal rearing and fish culture. Detail themes consisted of co-researchers field are (i) reclamation of the Polder, (ii) aerial photogram survey by balloon, (iii) set of vegetation community and trace of succession, (iv) cultivation of useful vegetation and crops, (v) trace of surface water flow, groundwater flow and water quality, (vi) management of irrigation water by groundwater or irrigation pond, (vii) control of salt accumulation in the Polder, (viii) soil physico-chemical properties, soil nutrient, etc.Research site was located at Khon Kaen distr … More ict in Northeastern Thailand 27HE06 : 230-242(N16ﾟ17'47", E102ﾟ39'08") where is barren, flooding and strong affected salt. Elevation of Bench-mark is 177.948m above sea level. The mainly land use in this area is rice field with not so high productivity as fluctuation of meteorogical condition is rather high and uncertain. Soil water erosion is so much by sandy soil. Salt accumulation in the surface soil is occurred by shallow blackish groundwater. Moreover, irrigation water in dry season is limited. Three bodies of the Polder were reclaimed by back hoe with the egg type shaped. Egg type of the Polder body was selected for protection from flooding. Each area of the Polder are 1600m^2 (No.1), 1120m^2(No.2) and 3200m^2(No.3). Area of diversion ditch are 1500m^2(No.1 and 2) and 1100m^2(No.3).The Polder body was stabled in pass one year after reclamation by covering of wild grass. It was estimated that roles of diversion ditch and polder body are as (i) groundwater control, (ii) irrigation water holding in rainy season, (iii) fish pond, (iv) protection from flooding, (v) barrier for invading of animals from outside, (Vi) mitigation of meteology in polder, etc. Cotton tree, acacia and eucalyptus were planted on top of polder body, some cash crops were examined in polder, and these growth were almost good. Less