A field experiment was conducted in rabi season during the period of December, 2017 to April 2018 with a view to evaluating the growth and quality traits of soybean as influenced by fertilizer management and rhizobium inoculation. The trail was laid out in split- split plot design with three replications. Three recommended dose of fertilizer viz. 75, 125 and 150% recommended dose of NPK; three levels of boron, viz. 1, 2 and 3 kg ha-1 and two levels of Rhizobium inoculation viz. with and without inoculation were used in this experiment. Application of recommended doses of fertilizer, boron and bio-fertilizer inoculation confirmed the positive effect on growth and seed quality of soybean. Lower level of recommended dose, boron and non inoculated plants showed less growth indices including total dry matter, crop growth rate; while the highest values of these indices were observed at the high levels of recommended doses of fertilizer, boron fertilization and inoculation of seeds with rhizobium. The highest germination (%) and vigour index were obtained from the 125% recommended dose of fertilizer, 3 kg ha-1 boron and bio- fertilizer inoculation. The overall result indicated that the application of 125% recommended dose of fertilizer, 3 kg boron ha-1 and inoculation of seed by rhizobium can be beneficial in improving growth and seed quality of soybean.
Keywords: Growth, yield, vigour index and soybean.
Introduction :Soybean (Glycine max) is an excellent source of protein and therefore, can supplement protein in human diet containing 40-45% protein, 20-22% oil and 20-26% carbohydrate soybean can play an important role in supplementing oil-protein deficiency in Bangladesh (Rahman, 2001). It has been cultivated in Bangladesh as a minor crop and little attention is given on the improvement of its yield potential. Moreover, the yield of soybean is low in Bangladesh as compared to other countries of the world (Nasreen and Bhuiyan, 1997). Integrated nutrient management practices applied for soybean contribute to sustainable growth of yield and quality, influences soil health and reduces environmental risks. So, the appropriate integrated nutrient management are necessary for high yield of soybean and quality seed. Research work relating to the integrated nutrient management on soybean growth, yield and seed quality is scarcely available in Bangladesh. Efforts for find out proper integrated nutrient management for achieving high yield of soybean. So, the present piece of study seems to be an important task. Sustainable agriculture based on using biological fertilizers is an effective solution for overcoming these problems (Ekin et al., 2009). Biological fertilizers can affect on yield and quality of product. Biological fertilizers containing useful enzymes and microorganisms that can increase plant growth and quality of crops, and reduce the cost of fertilizer and pesticide application (Chen, 2006). Determination of optimum nutritional requirements of plants is an essential component of the modern agricultural system. Although several studies on this subject have been reported, the role of boron (B) in plant nutrition still draws great attention among the studies on the plant-mineral relationship (Shireen et al., 2018). Integrated nutrient management (INM) enhances the better utilization of resources and producing crops with less expenditure. Again, sustainable agriculture, with its use of bio-fertilizer instead of chemical ones, bears high importance in overcoming the problems that have arisen from environmental pollution (Darzi et al., 2006). Bio-fertilizer contain various useful enzymes and micro-organisms which increase both plant growth and product quality, and reduce the cost of both fertilizer and pesticide application (Chen, 2006). So, the appropriate integrated nutrient management is necessary for high yield of soybean and quality seed. Research work relating to the integrated nutrient management on soybean growth, yield and seed quality is scarcely available in