Residual effect of integrated nitrogen management and cropping systems on soil physical and physico-chemical properties

Abstract
A field experiment was conducted to determine the residual effect of integrated nitrogen management and cropping systems on soil physical and physico-chemical properties during two consecutive years (2015-16 & 2016-17) on clayloam 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). Residual effect of integrated nitrogen management was non-significantly influenced all soil physical properties. Lowest bulk density, highest water holding capacity & porosity values, decreased pH values, improvement in soil organic carbon and CEC was found by Rice-blackgram cropping system followed by rice-sorghum and rice-maize.