Management Practices for Improved Soybean Profits

Farmers in Iowa and other Midwest states introduced soybeans into their cropping systems in the 1940\u27s and 1950\u27s, usually seeding the crop with the same wide-row (38- to 40-inch between row spacing) planter used for corn. In the 1960\u27s and 1970\u27s Iowa State researchers reported a consistent yield increase when soybeans were planted in narrow rows (10 to 20 inches between rows) versus traditional wide rows. Improved plant distribution and greater sunlight interception efficiency were cited as reasons for the yield response (Shibles and Weber, 1966; Shaw and Weber, 1967; Benson and Shroyer, 1978). At the time, most farmers depended on mechanical weed control practices (i.e. considerable pre-plant tillage and inter-row cultivation during early vegetative growth), so relatively few soybean acres were planted using no-till, narrow-row practices