Overwintering and Crop Residue Practices | Winter Crops | Geringhoff
Posted by: Todd Kamp on Nov 17, 2017 6:00:00 AM
Wintertime resonates with any farmer as a key season that affects the rest of the year.
In warmer climates, it can mean longer growing seasons or different crops taking their turn in rotation. Where it’s cold, it is a whole different ball game. Typically, any grain crop has to be out of the field and on to its next stop in the food chain. And, the field has to be left in a certain condition—before the freeze comes, and before the snow gets deep.
However, according to a Michigan State University Extension study by James DeDecker, that very snow is a welcome site in northern climates. A summary of his topline comments are summarized here:
- Snow accumulation of 30- to 200-inches provides between seven- and 66-percent of annual precipitation in Michigan. So, after a dry growing season, the value of that snowfall or precipitation is magnified.
- Also, it can extend the grazing season for livestock without the addition of a watering system. Plus, snow traps dissolve organic nitrogen, nitrate and ammonium in the atmosphere, which adds to soil quality.
- In addition, it provides value beyond the water it contains. Air caught within accumulating snow acts as insulation for the soil ecosystem. In fact, just two to four-inches can raise the surface temperature 30 to 35-degrees Fahrenheit. Many crops for overwintering, like winter wheat, are dependent on that insulation.
- On a related note from the Cover Crop, Planting Specification Guide from the Natural Resources Conservation Service, winter cover crops can also benefit from snow. With dormant seeding in early winter, the insulation aids in germination for these crops that aren’t for harvest, but prevent erosion and fix nitrogen in the off season.
Regardless of the planting need, some farmers leave stubble in the field after harvest to trap snow, and the benefits of that are clear. Trapped snow adds precipitation, insulation, and boosts nutrients.
A good example of a harvesting outcome impacting snow retention is the milo effect.
Milo is harvested close to the head to reduce shatter and reduce fodder going through the combine. That leaves substantial stalk in the field, and that, of course, is good at trapping snow. In short, how it’s harvested dictates the residue that’s left, and that in turn has the side benefit of overwinter snow retention.
One outcome enables the other.
However, stubble and other crop residue create other challenges for growers where winter means cold, freezing temperatures. There is less time for plant matter to decompose and add nutrients to the soil. That’s why crop residue management decisions go hand in hand with geography.
In Canada, for example, farmers harvest late and winter comes fast, according to a veteran farm equipment dealer there.
“Since we harvest late in the fall, we don’t have a lot of warm weather to help with managing the residue,” says Todd Botterill of Botterill Sales in Manitoba. “With the cooler weather, the residue doesn’t break down as fast, so the more we can do to break up the residue, the better off we are.”
He adds that harvesting with a stalk destruction system as part of a regional residue management strategy helps because it cuts the material into smaller pieces. It can get a head start on decomposition. Finer residue also helps avoid plugging of precision hoe drills that the farmers use come planting season in that area, he says.
Based on the particular needs and dynamics at play on any given farm in any particular location, it is about weighing the conservation considerations and basing decisions on that. Even in no-till systems, larger residue can be left behind. A light tillage pass may be made in the spring, according to 5 Tips for Successful No-Till Farming, a Geringhoff University article. This tillage pass just scratches the surface and puts some dirt on top of residue so that microbes and oxygen aid decomposition.
In short, it’s good to have choices, and the proper equipment can play a key role. This Minnesota farmer agrees:
“The Geringhoff Rota Disc does a great job with stalk destruction. It really shreds the stalks so that they can decompose over the winter,” says Andy Slinden, Don-Jo-Way Farms. “I think that’s the big benefit of the Rota Disc.”
But, everything isn’t all work and no play when planning how to manage winter on this farm. “We take time off during the winter. I like to snowmobile and dad likes to go south,” he says.
Overwinter decisions can get a little technical. But, the better one manages, the more opportunity there is for overwinter success, too.