If you drive around northwestern Indiana or in prairie areas during the next several weeks, you will see picket fences set up at key locations to help catch snow and prevent drifting onto roadways. If you left corn stubble relatively tall, or if you have cover crops with sizable growth, you may be able to help do the same job with "natural" snow deflectors.
Brian Musser, a district conservationist with the Natural Resources Conservation Service, says you can manage snow with residue and cover crops, and also learn from what happens to the snow after it drifts and sets for a few days.
The following information was prepared by Musser, with help from the Indiana Conservation Partnership, led by a team of NRCS personnel including Don Donovan, Clint Harrison, Musser and Ruth Hackman, district conservationists; Susannah Hinds, grazing specialist; Scot Haley, resource soil scientist; Kris Vance, public affairs specialist; Victor Shelton, state agronomist/grazing specialist; Tony Bailey, state conservation agronomist; and Shannon Zezula, state resource conservationist.
As you drive around Indiana this winter, pay attention to snowdrifts for both safety and learning reasons, Musser says. In many cases, the amount of snow that drifts on the road is based on the adjacent crop fields.
Musser has noticed that when fields have tall cornstalks or tall cover crops, the snow stays on the field and off the roads, compared to fields that are tilled have soybean stubble. Those cornstalks and cover crops greatly reduce the speed of wind across the surface of a field, and the snow is then deposited on the field. Taller cover crop species like millet, sunflower, sorghum or sudangrass are especially effective along roadways prone to drifting snow.
Keeping the snow on your fields also ensures there is adequate soil moisture, which will be critical during the crop year.
Also pay attention to the color of snowdrifts, Musser says. Drifts formed near fields covered by crop residue and cover crops are normally white. But drifts near fields that are fall-plowed or have little residue from silage or soybeans may have brown horizontal stripes.
Musser says those brown stripes are formed by valuable topsoil that blew off the field during high-wind events because the soil wasn’t protected. You may think of wind erosion as large dust clouds like the Dust Bowl images, but cold temperatures, freeze-thaw cycles and dry conditions during Indiana winters make the very top layer of these unprotected soils susceptible to blowing away.
The combination of cover crops and not tilling in the fall is the best way to eliminate wind erosion during winter months, Musser emphasizes. Contact your local NRCS office to find out how to adopt a system that incorporates residues and cover crops to protect your valuable topsoil and keep the snow on your fields.