Relative efficacy of different distillery effluents on growth, nitrogen fixation and yield of groundnut.

A field experiment with groundnut as test crop was conducted to evaluate the manurial potential of three distillery effluents: raw spent wash (RSW), biomethanated spent wash (BSW) and lagoon sludge (LS) vis-à-vis recommended fertilizers (NPK + farm yard manure (FYM)) and a control (no fertilizer or distillery effluent). It was found that all the three distillery effluents increased total chlorophyll content, crop growth rate (CGR), total dry matter, nutrient uptake (N, P and K) and finally seed yield compared to the control but inhibited nodulation and decreased nitrogen fixation. Among the three distillery effluents, BSW produced the highest seed yield (619 kg ha(-1)) twice that of control (3.10 kg ha(-1)), followed by RSW (557 kg ha(-1)) and LS (472 kg ha(-1)). However, the distillery effluents did not influence protein and oil contents. It was concluded that these distillery effluents because of their high manurial potential could supply nutrients, particularly potassium, nitrogen and sulphur, to the crops and thus reduce the fertilizer requirement of crops. Nevertheless, the crop performance and yield with three distillery effluents were overall less than that produced by recommended NPK + FYM probably on account of failure of the effluents to supply balanced nutrition to the plants for achieving their potential growth capacity.