Manure Management Improves Water Quality
With alfalfa in the crop rotation and pastureland in the mix, Stacy Miller’s 350-acre dairy farm near Plainview, Minnesota already played a role in filtering runoff flowing toward the Mississippi River.
With a new animal waste structure and nutrient management plan, the 85-cow operation now does even more to protect groundwater and nearby trout streams by enabling him to only spread manure when it is needed and not constantly due to lack of storage.
The 700,000-gallon manure storage facility is the second such structure constructed under the Lower Mississippi River Feedlot Management in Minnesota as part of the Regional Conservation Partnership Program (RCPP).Funded jointly by the Minnesota Board of Water and Soil Resources (MBWSR) and USDA’s Natural Resources Conservation Service (NRCS), the $3.2 million, five-year RCPP feedlot management project provides up to 90% cost-share to producers who build facilities that mitigate feedlot runoff. The project targets livestock operations with fewer than 500 animals in 11 southeastern Minnesota counties.
The targeted areas have karst geology below their surface soil. This means that the landscape rests on a rock layer of limestone that is water soluble. Karst landscapes are characterized by sinkholes, caves, disappearing streams and springs. These beautiful and unique features allow for anything, good or bad, that flows across the surface to quickly enter the groundwater.
“The whole purpose is trying to protect the surface water and groundwater in this karst landscape,” said Dave Copeland, the MBWSR board conservationist assigned to the project. “It’s a landscape that really needs livestock. It needs farmers out there who are going to have a diverse crop rotation, including that perennial hay rotation and including well-managed pastures. Along with that opportunity comes a need to manage the manure.”
Regional water quality data and modeling previously identified livestock operations as major contributors of nutrients, bacteria and sediment to Mississippi River tributaries. With no storage capacity, farmers often find it necessary to spread manure on their lands every day. Daily spreading can exacerbate local water quality issues, particularly in winter months when ground is frozen. With about 12 months’ storage provided by animal waste structures, manure application can be timed so that the nutrients are used by crops rather than running off into nearby streams.
The project plays a role in states’ nutrient-reduction plans to combat hypoxia in the Gulf of Mexico. The low-oxygen “dead zone” can be caused by excess nutrients including phosphorous and nitrogen.
“But closer to home, in this part of the state we have a nitrates-in-our-groundwater issue. So it helps address that as well. It’s addressing phosphorous in our surface waters (through) improved manure management that comes along with installing these systems,” Copeland said. “With those also comes improved oxygen levels in cold-water trout streams.”
Copeland said remaining project funds could build four or five more manure storage facilities. For the size of operations being targeted, the average cost is $400,000. More than a dozen applications are in the works. Besides the two lagoons, funding to date has helped about 10 producers develop comprehensive nutrient management plans.