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What's new in Dakota Lakes research?
From the highway, it looks like just another farm. A few buildings, research fields, and irrigation units break up this lonely stretch of South Dakota Highway 34. A stop at the Dakota Lakes Research Farm near Pierre, South Dakota, though, reveals a world-class research station. Here’s a look at what Dakota Lakes researchers are working on.
A conversation with the farm’s manager, Dwayne Beck, consists of a mix of agronomics, smart use of technology, resource management, and just a downright good time. Beck is a believer in soil moisture and nutrient management via no-till and diverse crop rotations featuring cover crops and grain crops like corn, soybeans, wheat and canola.
Cover crops, such as legumes like lentils or brassicas like mustards, are often planted following winter wheat. Even in dry areas like central South Dakota, soil moisture often is excessive from July winter wheat harvest until corn planting the following spring. Cover crops help manage excess moisture. Beck is taking this one step further by planting a perennial cover crop like alfalfa into this irrigated corn field that’s been in corn since 1990.
One of the goals of the alfalfa is to have soil mycorrhizae take nitrogen from the legume (alfalfa) and feed it to the non-legume (corn.). The alfalfa also cycles nutrients including calcium, magnesium, and nitrogen along with water from depths deeper than those reached by corn roots. This helps to stop nutrient leaking.
You never know what kind of crops you’ll come across at Dakota Lakes. You might think this sesame poking through previous residue is a new crop. Actually, sesame seed is considered to be the oldest oilseed crop in the world, having been domesticated over 5,000 years ago. It fits well with central South Dakota conditions, as it’s a drought-tolerant crop that grows where many crops fail.
Ever wonder where the lentils in your soup come from? Well, they are one of the crops grown at Dakota Lakes. Records of human consumption of this legume dates back up to 13,000 years.
Canola is another broadleaf that Dakota Lakes includes in rotational mixes. Canola oil is used in edible food products and also in the production of biodiesel. Canola oil’s low saturated fat level and beneficial omega-3 fatty acid content makes it the darling of dieticians.
This hard white winter wheat is part of a wheat-corn-broadleaf rotation that’s been grown for around 20 years. In recent years, winter wheat in this field has approached the 85 to 100 bushel per acre level. It likely won’t make that level this year, but yields still will be good in this dry year.
One unique feature is these wheat yields come with no insecticide, fungicide, or herbicides. “There are a few scraggly cheatgrass in here, but we will clean those up when we come in after it’s harvested,” says Beck. “We haven’t used insecticide on this farm for 10 years, so we’ve had a good level of predators build up,” says Beck.
Before European settlers broke the prairie, it consisted of 80% prairie grass. You’re seeing part of Dakota Lake’s goal to mimic that prairie makeup with two years of wheat (a grass), two years of grasses like corn or grain sorghum, and one broadleaf like field peas or soybeans. After last July’s winter wheat harvest, a cover crop mix of lentils/field peas/vetch and a Mighty Mustard brassica was planted.
“One thing about this mustard is it’s a pretty good soil fumigant,” says Beck. “It also gives us a lot of snow catch and sucked up lots of nitrogen (N) that was free, so the legumes (in the cover crop mix) had to make their own.” This spring, Dakota Lakes researchers drilled grain sorghum to evenly distribute plants across the landscape. Residue will be built with grain sorghum this year, followed by corn the next year and then a broadleaf like field peas.
Another advantage of having a high-residue no-till system with cover crops is an abundant earthworm and nightcrawler population. They create tunnels in the soil (filled by this pen) that greatly boost rainfall infiltration rates. This prevents soil runoff and helps ensure that moisture goes in the root zone where corps can access it.
See some of the latest crop innovations researchers are studying at this South Dakota farm.