Northeast Thailand is handicapped by unpredictable and uncontrollable availability of surface water: this usually suffers either from a shortage or an excess of water, both remain detrimental to sustainable of agricultural productivity. The south–west and the middle mountainous ranges boundary of region divide the whole northeastern watershed into two main river drainage systems namely “Sri-Songkhram” systems in the North and “Chi-Mun” systems in the South which both drain eastdownward to the great Mekong river systems. Each topography are characterized by mini watersheds in associated with various landforms called highland in hilly, upland and lowland formed rolling patterns in subsequently. These restrict to larger scale of water resources development. Remaining about 80% farm families are favorable and can make use to small scales water resources. Nevertheless, uncontrolled runoff water causes severely soil erosion and land degradation problems in highland whereas drought and flooding problem are common in undulated area. These factors play virtual role on overall agricultural productivity as well as farm families’ livelihood of this region.
The integration of technologies with natural resources such a soil, water and vegetative in a basin to optimum use in sustainable manner for betterment of people, two three-year phases on “Participatory Watershed Management for Reducing Poverty and land Degradation in SAT Asia” project, have been jointly implemented by a multisectoral consortium team with often trans-boundary approached by the ICRISAT and Thai research organizations under financial support of the ADB. This project have carried out in two benchmark watersheds of (i) a hilly landform “Tad-Fa” watershed in Phu Phamann District and (ii) a rolling landform “Wang-Chai” watershed in Phu Waing District, Khon Kaen Province, Northeast Thailand, since 1999 and 2003 in respectively.
The project interventions, especially the role of farm ponds in the watershed are discussed in details. Moreover, overall results have significantly increased the water availability and crop yields, and with the proper land use planning and with use of integrated soil and water management and crop management option, the land degradation, the results show that it can be controlled in which the soil loss of 5-6 t/ha/y indicated in improved systems vs. the soil loss of 25-33 t/ha/y in the traditional systems. A thirty nine of farm ponds, a key option of this integrated watershed management, have been governmentally implemented in the project area by the Land Development Department, constructed as small structure in farm land to capture surface runoff but some excavated enough to utilize ground water, each are about 1,260 m3 of storage capacities for the impoundment of water supplementary. Farm-ponds’ function indicates not only increasing crops yield in both rainy and dry season but sediment load drown-stream exhibited reduction. Farm pond water utilization indicated that hilly farm pond water was used for rainy vegetables, orchard, and home garden crops whereas rolling landform farm pond water was occasionally used for rainy paddy rice securing and supplementary used for various dry season vegetables and field crops cultivation such as cabbage, Chinese cabbage, fresh corn, groundnut, mung-bean, soy bean, etc. These direct farm ponds benefits enable farm families earn additional income in which about 85%, 10% and 5% were derived from vegetables, fruit trees and local herbs in hilly Tad-Fa watershed, meanwhile in the rolling Wang-Chai watershed, about 78%, 10%, 8% and 4%, were derived from paddy, fish, vegetables and fruit tree respectively. The factors effluent water ponding capability, lasting of water level maintained in a year round, indicated that soil types in associated with its complexities play various virtual roles to water ponding in hilly whereas the water ponding level show highly closed relationship to ground water level of rolling watershed. These can be anticipated that if proper water-soil-crop management where small scales water resources are paid much attention and achieved to integrate in watershed management, the other than farm ponds such as village tanks, weirs, marsh rehabilitation, dug ponds, and deep wells in particularly, also can play significant role for enhancement of farm productivity and better livelihood of small rainfed-farm families in Northeast watershed regional wide. Furthermore, the promising watershed management technologies developed at the project sites provides a good framework for increasing productivity and income on sustained basis, while improved soil and water resources nationwide.
