Does rolling soybeans after planting pay? It is too late to use that technology in 2015, but if has some value perhaps you can consider it in 2016.
Rolling the soil was developed as a way to level the soil and push rocks back down into the soil to make harvesting easier. This allows running the combine platform lower to pick up more pods without picking up dirt, rocks or stones. However, there is a cost to this practice plus the risk of damaging the crop, sealing the soil and increasing soil erosion by crushing natural aggregates that better withstand the forces of wind and water erosion.
Of course, if fields are littered with small stones and rocks rolling makes sense. But the question that has been raised is whether rolling can increase branching and pod set in soybeans. There is evidence that if you apply a burner herbicide (Cobra®) or a growth regulator at V2 or V3 you can increase branching and pod set—at least some of the time. And the same goes for rolling—some of the time it seems to increase branching. But is the increase in yield due to better harvest efficiency or increases in early branching and pod set?
If you physically damage the apical bud or growing point at the top of the plant, the axillary buds on the main stem and the axils of the trifoliate petioles will sprout branches and increase the number of pod sites on the plant. Seems that either chemical or physical damage or growth regulator stimulation can achieve this outcome.
But to do “damage” to the apical bud, the crop needs to be at least at V1 or V2 (1st or 2nd trifoliates) to have viable axillary buds. How late can you roll soybeans and get some of the benefits of rolling without damaging the crop and actually hurting yield?
A 3-year study out of Minnesota reported that soybeans can safely be rolled up to the V3 stage when plants are about 3” tall. They do not recommend rolling after V3 because of the potential for plant injury, lodging and wheel trafficking.
Improved harvesting efficiency and the potential for increased yield has to be weighed against its additional cost and whether rolling will damage soil quality.
Have you ever rolled a soybean field and experienced a benefit when harvesting or from increased its additional cost yield? Is it a practice you continue to follow today or would recommend to a neighbor?
Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at firstname.lastname@example.org or leave a comment below.