Influence of tillage, water regimes and integrated nitrogen management practices on soil quality indices in rice (Oryza sativa L.) in the Indo-Gangetic plains

Abstract

A field experiment was conducted on sandy clay-loam soil at New Delhi, during 2004 and 2005 to investigate the effect of irrigation regimes, namely, continuous submergence, one-day drainage, and three-day drainage, and integrated nutrient management practices on the soil biological health parameters under rice cultivation. The non-puddled soils showed significantly high soil respiration (17.32%) and soil microbial biomass carbon (45.51%) activity than the puddled soils. However, the soil dehydrogenase enzyme activity was 65.26% higher under puddled soils than the non-puddled. Among the integrated nitrogen management, substitution of 25% recommended dose of nitrogen (RDN) as biofertilizer resulted in highest (560.02 μg TPF g−1 soil 24 h−1) enzyme dehydrogenase (DH) activity and application of entire RDN as organics supported the highest soil microbial biomass carbon (218.29 μg g−1 soil) and respiration activity (56.67 mg CO2 [100 g−1 soil 24 h−1). In comparison with other organic N inputs, substitution of sewage-sludge for 25% RDN resulted in the least soil respiration (47.67 mg CO2 100 g−1 soil 24 h−1), low DH enzyme activity (313.37 μg TPF g−1 soil 24 h−1) and soil microbial biomass carbon content (183.85 μg g−1 soil). The present study suggests that inorganic, organic and bio-fertilizer combinations significantly improved soil health parameters.