Effect of Integrated Nutrient Management Practices on Available Nutrient Status of Soil under Rice-Sorghum Cropping System in Clay Loamy Soils

Abstract

A field experiment was conducted for two consecutive years 2020-2021 and 2021-2022 on clay loam soil at Agricultural College Farm, Bapatla to study the direct and residual effect of integrated use of organics and inorganics on soil nutrient status under rice-sorghum cropping system. The results revealed that at all the growth stages of rice, the highest available nitrogen, phosphorus and potassium were recorded with the application of 100% RDF + 25% N through GLM (T8) and this was on par with T9 (100% RDF + 12.5% N through FYM + 12.5% N through GLM), T3 (125% RDF through inorganic fertilizers) and T7 (100% RDF + 25% N through FYM, whereas the highest available sulphur was recorded in  100% RDF + 25% N through GLM (T8) and it was on par with T9 (100% RDF + 12.5% N through FYM + 12.5% N through GLM) and T7 (100% RDF + 25% N through FYM during 2020 and 2021.  In succeeding sorghum, significantly highest soil available N, P2O5, K2O and sulphur were recorded in T9 (100% RDF + 12.5% N through FYM + 12.5% N through GLM) and it was on par with T8 (100% RDF + 25% N through GLM) and T7 (100% RDF + 25% N through FYM) during both the years of study. Irrespective of the treatments applied to rice crop, the sub plot that received 100% RDF (S3) in rabi recorded significantly highest soil available nutrients at all stages of crop which was on par with 75% RDF (S2) except available sulphur whereas increased NPK levels from 75% RDF (S2) to 100% RDF(S3) did not show any significant difference and lowest was recorded in control (S1) during both the years of study, respectively.