Influence of different cropping systems and residual effect of INM on soil primary, secondary and micro nutrients

Abstract

A field experiment was conducted to determine the residual effect of integrated nitrogen management and cropping systems on soil nutrient status during two consecutive years (2015-16 & 2016-17) on clay loam soils of Agricultural College Farm, Bapatla. The experiment was laid out in a two sample t-test for rice in kharif season with 2 treatments consists of M1 100% RDF, M2 (50% RDN+ 25% N through FYM + 25% N through neem cake + Azospirillum + PSB @ 2.5 kg ha-1 (INM) and replicated thrice. During the immediate kharif, the experiment was laid out in a split plot design without disturbing the soil for succeeding rabi crops with the two treatments given to kharif rice as main plot treatments and each of these divided into five sub-plots of consisting of five crops as sub treatments by taking popular cultivars of rice (BPT 5204), blackgram (PU 31), maize (Sandhya), Sorghum (NSH-54), Sunflower (Shreshta) and mustard (Konark). Results shown that the highest mean available N, P2O5, K2O, exch.Ca, exch. Mg, S, Fe, Mn, Zn and Cu were recorded in blackgram, which was on par with mustard followed by sorghum and sunflower sequence, which was superior over maize. The lowest values were observed in maize sub plot. Interaction effect of cropping system and residual effect of INM, significantly highest available nutrient values were observed with M2S1 treatment i.e. rice-blackgram cropping system in INM treated plots during both the years.