Effect of distillery effluents on plant and soil enzymatic activities and groundnut quality

Abstract

A field experiment was conducted during the rainy season 2000 to examine the effect of distillery effluents, i.e., biomethanated spent wash (BSW), raw spent wash (RSW), and lagoon sludge (LS) versus recommended NPK+FYM (farmyard manure) on nutritional quality of groundnut (Arachis hypogaea L.) and enzyme activities of plant and soil. The distillery effluents did not affect the oil content (%), crude and true protein contents (%) in groundnut but increased the seed yield and the contents of methionine by 44 % (1.15 g (16 g N)–1 vs. 0.80 g (16 g N)–1 in control) and of cysteine by 24 % (1.36 g (16 g N)–1 vs. 1.10 g (16 g N)–1 in control). BSW produced the highest seed yield (619 kg ha–1) followed by RSW (557 kg ha–1) and LS (472 kg ha–1). LS recorded the highest total chlorophyll content (2.94 mg (g FW)–1) in groundnut leaves. Application of BSW and RSW significantly increased the activity of plant peroxidase whereas the plant polyphenol oxidase was higher in BSW only. The application of distillery effluents did not affect the nitrate reductase activity but BSW significantly increased the nitrate content in the rhizosphere soil. The three effluents significantly increased the dehydrogenase and alkaline phosphatase activity more than recommended NPK+FYM.