Impact of biomethanated distillery spentwash application on soil and water quality: A field appraisal

In Namakkal district, the boimethanated distillery spentwash from the Salem Co-operative Sugar Mills Ltd, Mohanur, has been applied in farmers' field, particularly in dryland, as a source of plant nutrients and irrigation water. The impact of spentwash application on soil and groundwater quality was assessed in areas previously applied with the distillery spentwash. The ground waters samples were collected from open wells near the spentwash applied fields in Namakkal district contained large amount of salts, particularly K+ and cr suggesting that the water contamination is mainly due to the application of distillery spentwash. More than 50% of the samples were found unsuitable for irrigation purpose as they have shown greater potential for salinity hazards. Though no marked evidence was observed on the soil characteristics, the nutrients (N, P and K) and salt (Na, Ca, Mg, Cl and SO₄) contents were relatively higher in these soils previously amended with the spentwash.