This study was undertaken to evaluate the effects of management practices on soybean plant characters. The objective of this study was to develop an optimum production system integrating tillage, fertility, cultivar, row spacing, and plant density;Two experiments were conducted each year during 1981, 1982, and 1983. Experiment I included four cultivars, three plant densities and three row spacings. Experiment II included three tillage systems and three levels each of phosphorus, potassium, and nitrogen fertilizers;Lodging, plant height, number of branches per plant, and number of nodes per plant were not affected by alterations in row spacing. Number of pods per plant and grain yield increased as row spacing decreased. Grain yield response to row spacing was positive and linear. Number of branches per plant, number of nodes per plant, number of pods per plant, number of seeds per pod, and grain yield decreased as density increased. Lodging and plant height were greater at high density than low density. The greatest lodging and plant height occurred with narrow row spacing and high plant density. Grain yield responded negatively and linearly with an increase in plant density;The determinate cultivars had less lodging, shorter plant height, a greater number of branches per plant, more pods per plant, fewer nodes per plant, and higher grain yield than the indeterminate cultivars. Plant characters of determinate cultivars were less influenced by changes in plant density than plant characters of indeterminate cultivars;Soil and leaf P and K content increased in time and with P and K applications. A greater number of pods per plant and seeds per pod were obtained with no tillage compared with conventional tillage. There were no differences in grain yield among different tillage systems. Lodging increased with P application. Lodging, plant height, number of pods per plant, number of seeds per pod, 100-seed weight and grain yield increased with K application. The relationship between grain yield and K application was positive and linear. Lodging, plant height, and number of nodes per plant increased with N application. Number of branches per plant and seeds per pod decreased with N application.