Problems and prospects of agricultural use of distillery spentwash in India

The disposal of wastes from industrial sources is becoming a serious problem throughout the world. In India, for example, approximately 40 million m 3 of distillery spentwash are discharged annually from 285 distilleries. The distillery spentwash is acidic (pH 250 m 3 / ha) spentwash application is found detrimental to crop growth and soil fertility, its use at lower doses (125 m 3 / ha) remarkably improves germination, growth and yield of dryland crops. Further, it has been revealed that conjoint application of spentwash and organic amendments (farm yard manure, green leaf manure and bio-compost) is found suitable under dryland conditions. Large amounts of soluble salts have been found to be leached from calcareous and high pH sodic soils amended with spentwash. Notably, application of spentwash has resulted in leaching of high amounts of sodium (Na) from high pH sodic soils reflecting its potential in ameliorating these soils. However, exceptionally high loading of the leachate with organic and inorganic contaminants may pose potential risk for groundwater contamination.