Land rolling helps conserve moisture, levels the soil, and pushes small rocks into the ground. Some producers roll immediately after planting, while others wait until the soybeans have emerged. Rolling immediately after planting provides improved seed-to-soil contact and reduces the likelihood of plant injury. But, it also increases the chance of soil crusting, which hinders emergence. Some growers choose to roll after emergence because there have been reports that early season stress from post emergent rolling may shorten internodes, increase pod number, and thereby increase yields.
OMAFRA conducted soybean rolling studies using a 30 inch diameter smooth roller. All treatments were replicated 3 times. Soybeans were planted in 15 inch rows with a row unit planter. A small tractor with 9 inch wide tires was used to avoid driving on emerged plants with tractor tires. Rolling was conducted in the afternoon when plants are less turgid and recover more quickly from rolling.
Results
Rolling soybeans after emergence provided a small yield gain but the statistical significance of the yield difference was weak. See table #1. There was no evidence of more pod development, so the improved yield was likely the result of better combine header performance. For those growers that choose to roll after emergence this study provides strong evidence that no yield loss is associated with that practice as long as best management practices are followed. Rolling at the first trifoliate is the best time to maximize yield gains and minimize plant stand losses.
Click here to see more...