The future of agriculture isn’t solely the domain of gleaming corporate headquarters teeming with industry scientists and pearly-toothed pin-striped-suited marketers. They’re important, of course. But if you want a glimpse of a where the future of agriculture really lies, look no further than this research farm on a lonely stretch of highway east of Pierre, South Dakota.
Billion Dollar-plus Bonus
That’s the location of the Dakota Lakes Research Farm. Dwayne Beck, farm manager, has worked with area famers to totally revamp central South Dakota agriculture. Thirty years ago, this area was mainly wheat-fallow. Thanks to tools like intense crop rotations, no-till, and cover crops that help cycle water and nutrients, area farmers now produce a cornucopia of crops. The additional revenue generated has been pegged at over $1.1 billion.
Every year on the last Thursday in June, Dakota Lakes holds its annual field day. It’s the best field day and meeting I spend on the job. Beck, Natural Resources Conservation Service (NRCS) agronomists, and South Dakota State University (SDSU) scientists always have some information that sticks like a barb in your brain and forces you to think differently.
What’s Up With Wheat
Winter wheat is still a mainstay of the region. Bob Fanning, an SDSU Extension plant pathology specialist, updated farmers on the latest in winter wheat varieties. The good news is the year’s cool temperatures are helping to shape an excellent wheat crop in South Dakota. The bad news is wet conditions fuel diseases like Fusarium head blight (scab) and wheat streak mosaic.
Bad Aphid Year Good For Farmers
Last year at the Dakota Lakes tour, Ada Szczepaniec’s sweep net oozed with aphids after several swings through a wheat field. This year, similar swings yielded far fewer aphids for the SDSU Extension entomologist.
That’s good news for the area’s wheat growers. “It is not a tremendous year for aphids,” she says.
Predators are key
Predators like this ladybird larvae help keep aphids in check via their voracious appetite. Remember that the next time you consider lacing a fungicide with an insecticide to control pests like aphids. Although you kill wheat-damaging aphids, you also kill their predators. No insecticides have been applied on the Dakota Lakes farm for 13 years. That’s encouraged a healthy population of predators to naturally control aphids that damage wheat.
Miller dug a shovel scoop from two fields with different rotations:
* A winter wheat/corn/field pea rotation. This is a 67% high-residue rotation. The carbon-packed high-residue crops in this one are corn and winter wheat.
* A flax/winter wheat/soybeans/corn rotation. With corn and winter wheat, this is a 50% high-residue rotation. This is the same residue mix as a conventional corn-soybean rotation.
No to Platy Soils
The 50% high-residue rotation had a platy soil structure, with roots struggling to grow through the densely packed soil. “A platy soil structure will slow down water from entering,” he says.
This is soil from the 67% high-residue rotation. This soil is filled with macropores (one in center) in which roots can follow and go deep into the soil. These soils are high in water infiltration and bode well for increases in organic matter, says Miller.
Boost Organic Matter
Increasing soil organic matter is key for soils. For every percent increase in soil organic matter, an additional 16,500 gallons of water is available in the soil. The long-term value of a 1% organic matter increase is estimated at $24 per acre in nutrient value and available water-holding capacity. (These estimates are based on an average 17 inches of precipitation in central South Dakota, and can vary among locations.)
Diversify With Winter Wheat
If you want to diversify your corn-soybean rotation, try winter wheat. In one Dakota Lakes trial, wheat followed by a cover crop was inserted into a long-term corn-and-soybean rotation. “In essence, the soil structure changed after just one year with wheat followed by a cover crop,” says Miller.
Retaining residue is key for building soil organic matter, Beck (back center in white-stripe shirt) says. He told about an ethanol project that was going to harvest corn stover after corn grain harvest. “They said, ‘Well, when we take off the corn residue, it will be just like a corn-soybean rotation." From an organic matter-building standpoint, though, a corn-soybean rotation doesn't cut it, says Beck.
Details, Details, Details
"They also said, 'When we take off the cornstalks, we can also get by with less N (nitrogen).’ Well, yeah, you can do that for a while, until you run out of organic matter," says Beck. In response, Beck sent a sharply-worded letter to the firm. “Details,” he says. “You have to keep asking about details.”
Cover crops, no-till, rotations at Dakota Lakes