RESUMO
Agronomic evaluation of fertilizing efficiency of the spentwash was carried out at the University of Agricultural Sciences, Dharwad in 2006. Initial chemical analysis confirmed its usefulness as a source of fertilizer as it consists most essential plant nutrients. Application of spentwash at the recommended level of nitrogen significantly affected both maize growth (plant height, number of leaves, leaf area, chlorophyll etc.) and yield (cob characteristics, test weight etc.) parameters. Spentwash is useful not only in meeting the crop N requirement but also other plant nutrients besides decreasing the current environmental problems faced by the industries. A highest maize yield (81.2 q/ha) was obtained when chemical fertilizer was replaced by the spentwash at the recommended nitrogen level. There was no advantage of applying spentwash higher than the recommended level in view of loading of soils with potassium. Application limited to the recommended level not only supplied N but also other essential plant nutrients. Spentwash substitution directly reduced fertilizer cost and thus benefited farmers by decreasing the cost with no adverse effect on soil's physical, chemical and biological properties when applied at the level recommended.