By Scout Nelson
A three-year on-farm research study examined the effects of using Exceed Superior Legume Inoculant on dry edible bean production. Researchers evaluated how the Rhizobium inoculant performed under different soil nitrogen conditions and whether it improved crop yields and farm profitability.
The inoculant contains the active ingredient Rhizobium leguminosarum biovar phaseoli. During planting, the dry inoculant was blended with bean seed in the planter box at a rate of 82.5 ounces for every 1,500 pounds of seed. Researchers monitored crop growth, harvest performance, bean quality, and harvest losses throughout the study.
Dry edible beans were directly harvested during September or October each year. Researchers collected bean samples from each test plot and analyzed them for quality factors. Harvest losses were also measured by counting beans in selected one-square-foot areas within harvested fields. The research was conducted using replicated and randomized plots with four replications to improve accuracy.
Soil nitrogen levels varied throughout the study. Total available nitrogen in the top 36 inches of soil measured 55 pounds in 2023, 73 pounds in 2024, and 94 pounds in 2025. University of Nebraska recommendations suggest that around 100 pounds of nitrogen supports top dry edible bean yields.
Researchers found that the inoculant performed best when soil nitrogen levels were below recommended amounts. In 2023 and 2024, the inoculant produced significant yield increases and slight improvements in net returns. However, in 2025, when soil nitrogen levels were close to the recommended level, researchers found no major yield or profit advantage from using the inoculant.
The study also highlighted concerns about rising nitrogen fertilizer prices and the risk of fertilizer leaching into groundwater supplies. Researchers suggested that lower-cost Rhizobium inoculants may provide producers with a practical tool for reducing fertilizer use while maintaining strong crop performance.
Although inoculants are not commonly used in areas where dry edible beans are grown regularly, the research suggests they may offer value when soil nitrogen levels are lower than recommended.
Photo Credit: gettyimages-studio2013
Categories: Nebraska, Crops, Education, General