A field experiment was conducted at Gabua, Noakhali to select a suitable fertilizer management practice for soybean cultivation, and a better land use system in the saline belts of Bangladesh from December 2019 to April 2020. Two soybean varieties (Shohag (PB-1), BARI Soybean-5), and three fertilizer doses were applied as treatments. Fertilizer treatments were F1 (100% of the recommended rates of chemical fertilizers, CF); F2 (Integrated nutrient management system, IPNS- 75% of the recommended rates of chemical fertilizers + 25% cowdung); and F3 (No fertilizer). The experiment was laid in Randomized Complete Block Design (RCBD) with three replications. Results reveal that IPNS had a significant effect on the plant height (37.95cm), branch number/plant (4.17), the effective number of plants/plot (161.7), number of filled pods/plant (69.1), number of unfilled pods/plant (3.70), number of seeds/pod (1.98), seed weight (20.64g/plant), seed-husk ratio (2.61) and seed yield (1.83t/ha), where as there were no significant effects on pod length (3.32cm) and thousand seed weight (141.9g). Leaf number, leaf dry weight, leaf area, and leaf area index were increased slowly upto 75 DAS, rapidly upto 95 DAS and then declined sharply. Total dry matter increased gradually upto 95 DAS and rapidly upto 135 DAS. The crop growth rate was increased gradually upto 75-95 DAS, rapidly upto 95-115 DAS, and thereafter declined. Relative growth rate and net assimilation rate increased gradually upto 75-95 DAS, rapidly upto 95-115 DAS, and rapidly upto 115-135 except control treatment. The highest amount of chlorophyll-a (15.02 µg/g), chlorophyll-b (4.38 µg/g), and their ratio (9.08) were observed in IPNS at 110 DAS. Chemical fertilizer increased the nodule number and dry weight compared with other treatments upto 75 DAS. Fertilizer management practice and variety had no significant effect on the oil content and pod initiation in soybean, where as pod initiation started after 83 to 84 days of sowing, and oil content ranged from 19.15-19.63%. It is concluded that the integrated use of cowdung and chemical fertilizer (IPNS) showed the maximum growth and yield in soybean and reduced 25% use of the recommended rates of chemical fertilizers.