Direct Use of Spent Distillery Wash Liquor on Paddy Fields in Thailand

Spent wash liquor (or stillage) from the Excise Department's distillery plant at Ubonratchathani Province, Thailand, has a flow‐rate of 550 m 3 /d. About 100 m 3 /d of the liquor are fed to an anaerobic digester by the ‘upflow anaerobic sludge blanket’ process ‐ the remainder being transferred directly to a large storage lagoon. The digested liquor is then diluted and pumped during the dry season (December to July) to 400 ha of paddy fields; this has resulted in a 2–3 fold increase in rice yield. Also, the liquor serves as an oxygen‐depletion aid which inhibits the growth of thrips and eradicates insect pests. In return, the farmers save 66–80 p/m 3 in terms of equivalent chemical fertilizer and insecticides. This direct use of spent wash liquor is a promising trend towards sustainable development in developing countries.