Response of Rhizobium inoculants and nitrogen application on productivity, uptake of greengram and microbial status of soil

Abstract

The field experiment comprising four Rhizobium inoculation treatments viz., no inoculation, inoculation with Rhizobium strains TAL-169, M-10 and AKR-1 respectively in main plots along with three nitrogen nutrition treatments viz., no N application, application of 20 kg N/ha at basal and top-dressing at 30 DAS, respectively in sub-plots, designed in split-plot, was conducted during 2017 and 2018 at the Instructional Farm, Jaguli of Bidhan Chandra Krishi Viswavidyalaya. Rhizobium inoculation and time of N application significantly influenced the number of nodules/plant, nodule dry weight/plant and leghaemoglobin content in greengram (cv. B-1). Among the different Rhizobium strains C2, i.e., M-10 strain proved to be efficient in improving the nodule characters and ultimately seed yield of greengram. Inoculation with M-10 Rhizobium strain coupled with basal application of 20 kg N/ha increased seed yield of greengram to the extent of 56.6% as compared to no Rhizobium inoculation along with no N application. N, P and K uptake by the crop was improved when the seed was inoculated with M-10 strain. Rhizobium inoculation also improved the soil health by increasing the population of total bacteria and non-symbiotic N fixing bacteria in soil after harvest of the crop.