By Mikkel Pates, Agweek
LAMBERTON, Minn. — Just as University of Minnesota football players hit the field for summer camp, a roster of tomorrow’s researchers are also hitting historic research fields, looking for long-term ways to improve tomorrow’s farming.
One of the new players on the field is Patrick Ewing, a doctoral candidate in agroecology and agronomy at the University of Minnesota. Agroecology is the study of ecological processes that operate in agricultural production systems.
Ewing studies soil structure and soil biological activity in cropping systems, comparing conventional chisel plowing with novel soil management systems that integrate zone tillage with cover-cropping.
His primary work is at the Rosemount (Minn.) Research and Outreach Center, but part of his time is spent at Southwest Research and Outreach Center in Lamberton, Minn.
Jeff Strock, a veteran soil scientist who supervises the Lamberton study, says it compares a variety of tillage systems — no-till, strip-till, ridge-till, chisel plow and moldboard plow — on both corn-soybean and continuous corn cropping systems.
Ewing was impressed with the strip-till trials, which are made by planting into nine-inch wide strips of tilled soil in the fall, leaving a bare strip of soil, with residue in between the strips untouched.
“It still gives you that early-season seed bed. In the non-tilled area, we have really nice soil structure — a little moist but not too bad,” Ewing says, picking up soil from beneath the residue. “If you press on it, the soil is crumbly and soft and pretty dry.”
Conservation systems in the study, such as no-till and strip-till, show far better soil biological activity and soil structure than conventional tillage. That’s measured by factors such as organic matter, mineralizable organic matter, soil enzymes and microbial respiration, Ewing says. He particularly looks at soil fungi, nutrient cycles, residue breakdown and microbial communities.
For the past eight years, the researchers have been studying the five tillage systems for responses to added sulfur. The conservation tillage systems tend to respond more consistently to added sulfur, he says. He indicates future studies will focus on how the practices affect soil moisture and soil-stored oxygen.
Strock says many factors affect how quickly new information from the studies will find its way out of academia and into common usage in farmers’ fields.
With lower commodity prices, and continued high land rent and other costs, farmers understandably will be less likely to spend money to switch to equipment that allows better conservation.
Strock says conservation tillage systems haven’t yielded as much as the more aggressive types of chisel or disk-plowing systems, but his studies show they cut some costs, including fieldwork time and fuel in reduced trips across the field.
“You actually see more adoption when you might have drought conditions — when conserving water with no- or strip-tillage might be more beneficial,” he says. “You have to convince farmers that it’ll be a benefit to them, beyond what they get at the end of the year in yield.”