VEERARAGHAVAIAH, RPRATHIBHA SREE, S2016-12-072016-12-072014170p.http://krishikosh.egranth.ac.in/handle/1/89414Development of crop nutrition schedules, which are environmentally safe and economically viable yet enhancing crop productivity and quality is much imperative for achieving food and nutritional security. Field experiments were conducted for two consecutive years (2010 -11 and 2011-12) on sandy clay loam soils of Agricultural College Farm, Bapatla in rice – blackgram sequence. The experiment was laid out in a split plot design with organic manures (green manuring in situ and FYM @ 10 t ha-1) along with and without zinc sulphate @ 50 kg ha-1 as main plots and four nitrogen levels (0, 60, 120 and 180 kg N ha-1) as subplots. At the end of rice, blackgram was sown as a relay crop without disturbing the experimental layout to assess the residual effects of treatments given to rice in rice – blackgram sequence. Popular cultivars of rice and blackgram BPT 5204 and LBG 752/PU31, respectively, were used in the study. Data collected on growth parameters viz., plant height, dry matter accumulation, yield attributes, grain yield, straw yield and nutrient uptake of rice were significantly higher with green manuring in situ + ZnSO4 @ 50 kg ha-1 as basal during both the years of study. Irrespective of the organic manures, higher nitrogen application i.e., 180 kg N ha-1 also recorded higher growth parameters during both the years of study. Higher protein content (%), amylose content (%), hulling (%), milling (%), head rice recovery (%) and volume expansion ratio were recorded with higher levels of nitrogen (i.e., 180 kg N ha-1). Higher iron and zinc concentrations were recorded with green manuring in situ + ZnSO4 @ 50 kg ha-1 as basal during both the years of study. In general, nitrogen use efficiency, expressed in terms of Agronomic Efficiency (kg grain/ kg N applied), Physiological Efficiency (kg grain/kg N uptake) and Apparent N Recovery (%) was found to be better in combined application of organic and inorganic sources of nitrogen application when compared to no nitrogen application. Higher residual fertility status i.e., in the form of available N, P, K in soil was recorded with green manuring in situ + ZnSO4 @ 50 kg ha-1 as basal along with 180 kg N ha-1 which in turn resulted in significantly higher seed and haulm yields of blackgram during both the years of the study. Higher gross returns, net returns and benefit cost ratio were recorded with green manuring in situ + ZnSO4 @ 50 kg ha-1 as basal along with 180 kg N ha-1 to rice in the sequence. Overall, the study, conducted for two consecutive years, indicated that green manuring + ZnSO4 @ 50 kg ha-1 as basal + 180 kg N ha-1 to rice increases productivity and quality of these crops in the sequence.en-USThesis