In the day all farmers used livestock to help them get in crops and get maximum benefit from their farming efforts. Even though their main cash crop might be grain, such as wheat, they also raised cattle or at least fed some cattle in winter for ranchers. After the crop was harvested they would put in the cattle to clean up residues. The cattle got fat on crop trash, which included some amount of grain that escaped the combines due to lodging or shatter, and the fields got fertilized by dung and urine.

Fields in higher latitudes where winters were cold and snowy got special handling.

Swath grazing is a way to revive the once widespread practice of letting cattle graze all winter in the Northern Plains. With swath grazing, farmers pile crop residue into rows, known as “swaths,” that stand as high as 16 inches. Cattle can usually push with ease through up to 2 feet of snow to graze on these crop residues or other high quality forages.

Northern Plains farmers and ranchers largely gave up the historical practice of grazing cattle on pastures or rangelands year-round in the late 1800s, after two severe winters caused extensive cattle losses from blizzards and a lack of reserve feed supplies.

But swath grazing, backed up by supplemental harvested grain, saves farmers money and labor compared to feeding cows hay in a corral near a barn during winter. . .

Swath grazing also helps farmers by eliminating the need to remove and store manure from winter cattle corrals. Instead, the cattle distribute the manure naturally, as they graze, improving soil quality and crop production.

The disadvantages are seen when ice or deep snow prevents cows from reaching the swathed residue. But those problems can be solved by mechanically breaking up the ice or snow.

I've read about those blizzard years that so hugely altered practices on the Northern Plains. It's interesting in several ways since capital was often foreign, mainly British, in that period after the civil and Indian wars until the closing of the frontier around the turn of that century. Many British aristocrats lost their capital in those blizzards, and then withdrew from the business. The story of the taming of the American west doesn't always make clear how much of it was done by European investors, something that should be better understood by nations still developing. That foreign capital and land ownership was essential and beneficial.

It's not a done deal. We are still learning how to do ag in these places.

Providing swathed forage for wintering pregnant beef cows was part of the study, in which scientists also sought to test a 3-year crop rotation to minimize use of store-bought nitrogen fertilizer and pesticides. They also wanted to determine the impact of livestock presence on no-till grain and forage production, whether for sale or to feed livestock.

The rotation used an oat and pea mix the first year, then a triticale and sweet clover mix, followed by drilled corn the third year. All were grown without tillage, and crop residue was left in swaths for livestock grazing.

The combination of no-till and annual crop rotations can give farmers higher yields, more agricultural stability, fewer crop pests, more protection against drought, less soil erosion, and more efficient use of precipitation. Farmers can also slash nitrogen fertilizer needs in half by planting legumes like clover and using nutrients in manure more efficiently.

No-till wasn't done in those early days before conservation tillage was recognized as essential and the materials, equipment and methods of no-till were available to growers. With the price of grains so high and the cost of inputs rising too there are many incentives to developing more complex and sophisticated systems that revive the spirit of general farming of the past even though the specifics vary wildly. It's doing something analogous even if the techniques are novel.

To solve the problem of millions of acres of grazing cropland in the northern Great Plains being ecologically degraded and under-producing, Tanaka and colleagues seek innovative ways—like swath grazing—to better integrate crop, forage, and livestock systems to make them economically and environmentally sustainable.

Hanson, who leads research at the Mandan lab, calls this “dynamic farming.” He and colleagues offer farmers more than a dozen crops to choose from each year, with more than 100 possible rotation combinations.

Hanson says, “All of this was made possible in the Great Plains by the introduction of no-till and related conservation-tillage techniques, which leave a cover of unharvested plant parts to slow moisture evaporation from the soil. This means there’s enough moisture in the soil to sustain crops just about every year.”

These diverse cropping systems for forage and grain production include cool-season annual crops, such as oats, peas, and triticale; warm-season annuals, such as corn; and biennial (short-lived perennials) legumes, such as sweet clover. This diverse mix allows farmers to use crops that take advantage of erratic rainfall and snowmelt frequency and distribution in the northern Great Plains.

“Adding diversity brings sustainability to farms, both economically and environmentally,” says Hanson.

Including livestock in the mix is probably the most important way to create this stability. Bringing cows back to graze on family farms year-round is a natural, easy, and profitable way to recycle manure as a soil conditioner, and it helps both soil and crops make the best use of precious, but erratic, precipitation.

I shudder to think that biofuel advocates want to gather up crop trash and burn it though it is more valuable when left in the fields if we think in terms of soil health and the long term viability of such crop land.