G90-963 Narrow-row Soybeans

Narrow-row spacing of soybeans may be a profitable practice with modern herbicides and new lodging-resistant varieties. This NebGuide describes considerations for producing narrow-row soybeans. Early in this century crop row spacing was determined by the breadth of the animals used to work the fields. Spacing had an impact on methods of weed control and the varieties of soybeans developed. Even a decade ago row spacing was determined by tractor tire size since cultivation was required. Also, the tall varieties of soybeans lodged severely in narrow-row systems. However, the broad spectrum of herbicides now available and lodging-resistant soybean varieties have made narrow-row soybeans more practical. Narrowing soybean row spacing can increase yields if light utilization is the yield-limiting factor. The main purpose of narrow rows is to intercept more light. Unlike fertilizers and water which can use the soil as a reservoir, light falling on bare soil cannot be used. Decreasing row spacing results in more rapid canopy closure and increased light interception. Canopy closure at or shortly after flowering will maximize yields in ideal conditions. However, Nebraska\u27s growing seasons are rarely ideal. Any yield limiting factor like lodging, weed growth, moisture stress, soil compaction, high soil pH, or nutrient deficiency will reduce soybean yield responses in narrow rows