Written by Jonathan Eisenthal
Farmers want to know the volume of nutrients and sediment leaving their land. Eleven such producers across the state of Minnesota take part in Minnesota Discovery Farms Network, and three of these farms hosted a tour of agricultural water quality experts on Aug. 13-15 from states that have each developed their own Discovery Farms network.
Warren Formo, director of Minnesota Agricultural Water Resources Center, and George Rehm and Tim Radatz, with Minnesota Discovery Farms, organized the tour, which involved bus travel from the Twin Cities to Mankato, Willmar and Sauk Centre.
The Discovery Farms idea is to collect real world nutrient and sediment loss data – a good counterbalance to laboratory information. The Discovery Farms model now exists in a half-dozen states including Illinois, Wisconsin, Arkansas, the Dakotas and Minnesota.
Over the course of three days, water quality experts from these states, many of them active participants in their own state-based Discovery Farms networks, came to see and learn about Minnesota’s approach to long-term on-farm measurement of nutrient and sediment loss.
To see how conservation methods work and to understand the impact of conventional methods, according to the Discovery Farms philosophy, these methods need to be viewed in the contexts where they are a regular part of the farmer’s agricultural practice — using their soils, their inputs, their equipment, and subjected to real sun, rain, wind, heat and cold. The farmer continues to make all the agronomic decisions, and the Discovery Farms team collect the data. Monitoring stations are set up at the edge of fields, and collect samples from either surface flows, tile drainage flows or both. To get truly representative samples, the list of discovery network sites includes farms that raise only crops, and others that raise a combination of crops and livestock.
The tour visited Half Century Farms, near Mankato, owned by Doug Hager; Gorans Brothers Farms, near Willmar, where co-owner Kim Gorans spoke to tour goers; and Meyer Dairy near Sauk Centre, owned by Nick and Tara Meyer.
The group started the tour by seeing something off the farm. They visited sites along the Minnesota River valley bluffs that illustrate v-cut erosion, driven by groundwater flows. Unstable elevations give way during rainstorms and form ravines that shed thousands of tons of soil — scientists estimate that as much as 85 percent of the sediment in the Minnesota River derives from these phenomena — an important element in the context of understanding sediment loads in the river.
On the first day of the tour, the group visited Hager’s farm, where he raises corn and beans on a poorly drained silty clay loam soil. This has necessitated tile drainage, spaced at 80-foot intervals and four feet deep. He uses a chisel to work the soil and then knifes in manure. Manure is not applied on all his fields every year, and in its absence, Hager puts down 160 pounds of nitrogen per acre, split between a fall application and a pop-up. Through his management techniques, Hager has been averaging 180 bushels of corn per acre, and 57 bushels of soybeans.
Gorans also uses manure in corn and soybean production, much of which then goes into its production of turkeys. They have poorly drained calcareous soils, and have installed tile drainage spaced 60 feet apart. This was the first monitoring site, and has generated data since 2007. For economic reasons, they are changing over after this year from a corn-corn-soybean rotation to continuous corn.
Among the practices they have implemented have been a woodchip bioreactor and the use of a wetland as a filter for tile drainage, before that water reaches a lake. Discovery Farms monitoring finds the wetland filter has reduced nutrient flow 90 percent.
Tour participant Dr. Shalamar Armstrong, from Illinois State University, discussed the differences in phosphorous loss between Discovery Farms sites in his state and the Goran’s site, where it is a particular concern because of the lake adjacent to their farm. Armstrong noted a predominance of iron-bearing soil which binds the nutrient, where the calcium rich soils on Goran’s may impact the solubility of the phosphorous.
Local farmers, government and conservation leaders also visited the tour sites. MCGA president Tom Haag and MCR&PC liaison to Minnesota Discovery Farms, David Ward, both enjoyed seeing the Goran Brothers farm and hearing about the findings from the field edge monitoring station.
Minnesota Agriculture Commissioner Dave Fredericksen addressed the group as it began its three days of tours and a number of officials from local Soil and Water Conservation Districts and regional Minnesota Pollution Control Agency representatives participated in the tour.
The Meyer Dairy, one of the most recent operations to join the Minnesota Discovery Farms network, has a variety of soils and utilizes manure produced by their dairy herd, supplemented by commercial nitrogen. They rotate between corn and alfalfa and achieve a grain yield around 224 bushels per acre and, adding up the four yearly cuttings, harvest six tons of alfalfa per acre.
For each of these operations, the goal is to measure nutrient and sediment flows for a period of seven years if not longer, in order to get a good range of weather — rainfall being the most immediate factor in both nutrient and sediment flow.
The Meyers have implemented structures that channel the flow of rainwater so that it joins the effluent from the barns in the manure containment system, and they use no-till for their grain production. The latest innovation added to the operation is a manure separator that allows them to collect dry solids that make excellent bedding material for the cows, and limiting the flow so that mainly liquids end up in the manure pit.
“Hopefully farmers across the state will get to know about Discovery Farms and like what they see,” said Emily Krekelberg, an educator with the Stearns-Benson-Morrison County office of University of Minnesota Extension. “Discovery Farms participants want to help make things better for farmers all over the state—they are examples of great management. You can see everything that they do so well here. Many farmers want to make changes, but they might not be sure about the first step. Word of mouth travels fast so we think Discovery Farms can have a real impact.”
“This is a family that is sharp about what they are doing,” said Dan Martens, a crop production specialist with the Stearns-Benson-Morrison County office of University of Minnesota Extension. “They are learning every day and then making adjustments based on what they are learning. They do their homework before jumping into anything.”