From the ground up: Insects featured at Soil Health Day

Farm Forum

DAKOTA LAKES RESEARCH FARM – Usually it’s bad news if a farmer’s fields are full of insects.

Not so on the Dakota Lakes Research Farm east of Pierre that Dwayne Beck manages as a showcase of no-till ag techniques and crop rotations suitable for central South Dakota – here it’s just more evidence of how charting a different course in agriculture can pay off for the producer.

Beck is a South Dakota State University scientist and operates the research program on the farm, which is owned by the not-for-profit Dakota Lakes Research Farm Corp.

Among the studies that made producers open their eyes wide on July 14 at the South Dakota Soil Health Coalition’s 2015 Soil Health Field Day was one that deliberately sowed corn rootworms into Beck’s fields.

“We looked at rootworm performance, which is one of the key pests of corn throughout the U.S., and we looked at predator communities in the soils. This is something we studied in multiple, multiple farms – dozens if not hundreds of farms throughout eastern South Dakota,” said Jon Lundgren, a research entomologist with the USDA’s North Central Agricultural Research Lab in Brookings. “To study it, we infested a thousand corn rootworm eggs per row foot into Dwayne’s soil. And then we put emergence cages to see how many rootworms come out, and we look at the damage that’s caused by the pests.”

And the damage amounted to nothing.

“There was no appreciable damage,” Lundgren said. “We saw almost no rootworm adults come out of the soil. So out of a thousand rootworm eggs per row foot, nothing survived.

“We decided to do some soil cores. We used a golf cup cutter and then looked inside those cores to see which of the predators or which other insects are living within the soil. We found on Dwayne’s farm the highest predator population that I think I’ve ever seen. It was up to a billion predators per acre, when you extrapolate it out, just living in the soil. Any pests that arrive are lunch for so many of these different critters.”

The researchers looked deeper to learn more about what was going on.

“We actually looked inside those predators’ stomachs for rootworm DNA to see which predators had actually eaten the pests,” Lundgren said. “We found that 19 percent at Dwayne’s farm – normally it’s 11 percent – had tested positive for eating corn rootworm DNA within the last eight hours. So out of a billion predators, 19 percent ate corn rootworm DNA in the last eight hours. There’s a lot of predation going on.”

But the message at Soil Health Field Day was that it’s going on in healthy soils, a place where complex relationships are not always well understood.

“That’s the problem,” Beck told the Capital Journal later in the day as more than a hundred visitors to the farm took a lunch break out of the sweltering heat in one of the farm’s buildings. “We see a bug, we want it dead. Ninety-five percent of the insects and nematodes, whatever, are beneficial. We’ve been fooled into thinking that we just can kill them and everything’s OK. But even if we kill something that’s a bad insect, from our perspective, it might be food for something else.”

Sandy Smart, a South Dakota State University range scientist, said more and more farmers and ranchers are beginning to understand the importance of healthy soil.

“If you strictly go by physics and biology, essentially plants are your solar panel that’s harvesting sunlight and carbon dioxide in the air. That’s your factory, and the soil is the place that anchors all those plants where all the biology is happening to make that system work,” Smart said.

That’s true whether the plants are seasonal crops the farmer grows or perennial range plants that the rancher converts to meat via livestock.

That was what drew more than 100 people to the Dakota Lakes Research Farm on for the South Dakota Soil Health Coalition’s Soil Health Field Day.

Mark Weinheimer, who has a diversified no-till operation north of Pierre and west of Onida, said Dakota Lakes Research Farm manager Dwayne Beck’s operation has been influential for him and others in seeing no-till techniques and soil-building rotations in action before they try them. Beck has made many farmers in the region believers, Weinheimer said.

“There are people who come from all over the world to see what’s going on here,” Weinheimer said. “Some of the stuff that’s been adopted in the neighboring area has really helped the agricultural community as a whole.”

Anthony Bly, a soils field specialist for SDSU Extension, agreed the farm has been very influential – and so has Dwayne Beck. Revered as an authority on no-till farming internationally, Beck is in the South Dakota Hall of Fame for a reason, Bly said. And, he added, Beck’s work is vitally important for everyone.

“In history we know that civilizations have come and gone based upon that resource. It’s really the basis of our society – the productivity of our soil,” Bly said.