Growing the on-Farm Soybean Research Program in South Dakota.

In many fields, yields can be limited by lack of soil moisture in upland positions and by excessive soil moisture in poorly-drained lowland positions. Yield potential is usually high in areas between these extremes or where lowland positions are well-drained. Therefore, a single management practice across an entire field that is optimum in all of these environments may not be possible, or may greatly increase production costs in areas where the practice may not work well. Since starting the South Dakota On-Farm Soybean Research Program in 2014, we’ve noticed that: 1) the optimum soybean seeding rate should be higher in upland than lowland positions, 2) foliar soybean fungicides are more effective in lowland than upland positions, and 3) slow-release N fertilizers can increase yields in backslope areas. Analyzing yield monitor data by traditional methods, such as a randomized complete block design where treatment strips across an entire field are treated like small plots and compared to adjacent untreated strips, has usually resulted in no significant yield differences. However, when fields are separated into management zones based on elevation data and yield differences, treatment by landscape differences can be observed. Farmer collaborators are selecting practices they want to investigate and using on-farm research to improve management on their farms.