Direct and Residual Effect of Integrated Nitrogen Management on Physico-Chemical Properties of Soil

Abstract

Aim: To find out the direct and residual effect of integrated nitrogen management on physico-chemical properties of soil under rice – maize cropping system. Study Design: The experiment was laid out in randomized block design during kharif season and in split plot design during rabi crop. Place and Duration of Study: At Agricultural college farm, Bapatla during 2018-19 and 2019-20 in Kharif and rabi seasons. Methodology: After the preliminary layout, paddy was sown in kharif and maize was sown in rabi season. Vermicompost and green leaf manure were applied two weeks before sowing of paddy. Treatments applied for paddy were considered as main plots and each one divided into two sub plots during rabi. Results: Applications of different treatments did not show any significant difference in physico-chemical properties of soil (pH and EC) at all the growth stages of rice and maize during both the years of study. Application of 75% RDN through green leaf manure + 25% RDN through inorganics (T5) to rice during kharif significantly improved organic carbon in both kharif and rabi seasons whereas different levels of fertilizers applied have not shown an significant influence on soil organic carbon content. Conclusion: Application of inorganic fertilizers, organic manures and their combination didn’t show marked difference on physico-chemical properties of soil like pH and EC. However substitution of 75% N through GLM in kharif season significantly improved OC content in soil during both kharif and rabi and organic carbon content was not influenced by the level of fertilizers from 50% RDF (S1) to100% RDF (S2).