Soil dehydrogenase enzyme and microbial biomass carbon as influenced by integrated nutrient management under cabbage cultivation in acid Inceptisol of Meghalaya

Abstract

To investigate the influence of integrated nutrient management on soil dehydrogenase enzyme activity and microbial biomass carbon in acid Inceptisol, a field experiment was conducted at School of Natural Resource Management, College of Post Graduate Studies in Agricultural Sciences, Umiam, Meghalaya during rabi 2017-18. Cabbage (Brassica oleracea L. var. capitata) cv. Wonder Ball was raised as test crop with eight different combinations of doses of Farm Yard Manure (FYM), Vermicompost (VC) and recommended doses of NPK fertilizers (RDF). The treatment combination consists of control (T1), 100% RDF (T2), 100% N through FYM (T3), 100% N through VC (T4), 50% RDF + 50% N through FYM (T5), 75% RDF + 25% N through FYM (T6), 50% RDF + 50% N through VC (T7) and 75% RDF + 25% N through VC (T8). The experiment was laid out in RBD and replicated thrice. The experimental soil was having pH 4.87, SOC 1.24%, Alkaline KMnO4- N 160 kg/ha, available P2O5 18.60 kg/ha and available K2O 238.4 kg/ha. The experimental results revealed that treatment T7 with 50% RDF + 50% N through VC produced highest cabbage yield (60.44 t/ha) which was statistically comparable with T5 of 50% RDF + 50% N through FYM (54.33 t/ha). Significantly higher soil dehydrogenase enzyme activity (DHA) and soil microbial biomass carbon (SMBC) was observed under all organic manures treatments over the control and sole inorganic treatments. Among the organic treatments, T3 (100% N through FYM) recorded highest DHA and SMBC. In both combined treatments, farm yard manure treated soils (T5 and T6) showed higher DHA and SMBC over vermicompost treated soils (T7 and T8) indicating superiority of FYM over VC in maintaining soil biological health after harvest of cabbage.