Spotlight on Discovery Farms Minnesota
Written by Jonathan Eisenthal
Discovery Farms is a farmer-led, edge-of-field, monitoring program that studies the relationship between agriculture and water quality. Four states — Arkansas, Minnesota, Vermont, and Wisconsin — have Discovery Farms programs. In Minnesota, the program is run by the Minnesota Agricultural Water Resource Center (MAWRC) and supported in part by Minnesota Corn.
Below is a recap of a March 27 presentation about Discovery Farms Minnesota made during a webinar on the four Discovery Farms programs.
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Discovery Farms Minnesota has collected edge-of-field data from Minnesota farms for about 15 years, accumulating more than 50 site-years of data, according to program coordinator Tim Radatz. At each farm, scientists install an edge-of-field water-monitoring system that measures runoff volume, nitrogen, phosphorous, total suspended solids, and more.
The data shows that surface runoff is the conduit for most phosphorus movement while tile drainage is the conduit for most nitrogen movement, which occurs in the form of nitrates. To address nitrate movement, Radatz said it’s imperative that farmers focus on proper nitrogen management, including the four Rs — applying the nutrient at the Right rate, Right place, and Right time while using the Right source.
In recent years, Discovery Farms Minnesota has set up on-farm experiments to study how conservation practices affect nitrogen movement. In one section of a southern Minnesota corn-bean rotation field, the program and a local grower implemented cover crops and limited tillage. The grower continued with conventional management practices in the other section of field.
Because the two areas of the field drain into different basins, Discovery Farms Minnesota can use the information to see how conservation practices affect nutrient movement. Unfortunately, drought has limited tile flow on the field to date, so it’s been unclear how the conservation practices have affected nutrient movement.
This year, Discovery Farms Minnesota is beginning a similar study on a Stearns County farm in a corn sileage-bean-wheat rotation. The program and the local farmer will continue with usual management for several years before planting cover crops in one section of the field while continuing as usual in other sections.
Because the Stearns County field includes corn silage — which is harvested earlier than field corn — Radatz said he expects they’ll have an easier time establishing cover crops at the site.
Addressing a drainage myth
During the March 27 webinar, Radatz noted how tile drainage allows crops to grow to their maximum potential, reduce surface runoff and soil erosion, and help ensure optimal crop fertilizer uptake.
He also noted that tile drainage systems don’t create drought conditions in soil. Rather, he said water only flows into tile drains when soil pore space is completely full — meaning when the soil is at its moisture capacity additional water runs through the tile drainage, leaving the field with the ideal amount of water to help crops thrive.
“Tile drainage can only remove water that moves freely with gravity,” Radatz said. “It does not create suction. It does not pull that water out that is held in the soil matrix. All that water is not removeable by tile drainage.”
Benefits of sharing information
Radatz said he appreciated the opportunity to hear from the other Discovery Farms programs, each of which has different landscapes, climates, and crops.
Of the four states, Arkansas, with its main crops in peaches, cotton, and rice, is arguably the most different from Minnesota when it comes to agriculture. Almost all Arkansas farmland is irrigated, while most Minnesota farmland is not.
Still, the concerns expressed by University of Arkansas Prof. Mike Daniels, who directs the state’s program, seem to overlap with those held by Minnesota farmers. The Arkansas program measures soil and nutrient loss and work on water quality. A focus of late has been climate resiliency — that is, adapting to changes in intensity and volume of precipitation. More frequently, Arkansas farmers face deluges of rain and then periods of drought, often in the same growing season.
Minnesota farmers are facing similar challenges. Radatz said the state is also getting more intense bouts of precipitation in shorter time periods as the climate warms.
To learn more about Discovery Farms Minnesota and its research, visit the program website. Watch a recording of the multi-state webinar here.
