Rolling do’s and don’ts revealed
There are some definite do’s and don’ts when it comes to rolling soybean ground, says Hans Kandel, North Dakota State University Extension agronomist.
Do roll fields just after planting, but before soybeans emerge. The advantage with rolling before the crop has emerged is improved seed-to-soil contact, Kandel explains.
Don’t roll when soybean seedlings are just emerging. When seedlings are in the crook stage (cotyledons just being pulled out of the soil), the stems may easily break. Plants will die if the stem is broken below the cotyledon leaves, because there are no growing points below the cotyledons.
• Timing is an important consideration when rolling soybean ground.
• It’s best to do rolling after seeding, but before soybeans emerge.
• Rolling after emergence is possible if you wait for the right conditions.
Rolling fields after soybean plants have fully emerged may cause some plant injury such as cracked or broken stems. Injured plants may be more susceptible to lodging and disease.
Limit injury potential
University research and observations by farmers indicate that rolling between the cotyledon and first trifoliate stages of soybean may limit injury potential, Kandel says.
Also, rolling during the warmest part of the day with less turgid plants may reduce potential plant injury. The percentage of damaged plants reported in university trials in 2003 and 2009 was approximately 20% for postemergence rolling.
Rolling studies indicated a trend of lower remaining plant population as rolling was delayed from preemergence to the second trifoliolate soybean growth stage. However, seed yield was similar among the unrolled check and all rolling treatments.
Kandel says he’s noticed several things about rolling:High residue levels may protect the plants from damage during postemergence rolling.
Plant damage in the wheel tracks (with postemergence rolling) is likely to be more severe than in the rolled area.
Soybean plants are able to compensate, and although there may be stand losses or damaged plants, the yields at the end of the season tended to be similar between postemergence rolling and preemergence rolling.
In certain soil types there may be a higher risk of sealing or crusting the soil.
Rolling increases the risk of soil erosion.There is an additional cost to own or rent a roller and go over the field with a tractor pulling the roller.
Harvesting a soybean crop that has been rolled is easier. The clods and root balls from the previous crop have been pushed into the soil surface. You can run the combine cutter bar a little lower, and you can operate the combine a little faster. Being able to set the cutter bar closer to the ground means you reduce harvest loss.
Harvesting soybeans in a field that has been rolled also decreases the risk of rocks going into the combine and damaging the equipment.
Rolling a field may also help with the decomposition of the previous crop’s residue, especially cornstalks.
This article published in the February, 2011 edition of DAKOTA FARMER.