Tour a window into Linn County farmers’ conservation efforts

MARION - Linn County farmers showed some of the ways they are reducing the flow of nutrients into surface waters Thursday during an agricultural conservation tour.

'This is not a tour to snowball public opinion. We know we have issues to address,” said Curt Zingula, natural resources chairman for the Linn County Farm Bureau, one of the tour's sponsors.

The tour sites - a wetland, a confined hog feeding operation, a large buffer complex and a farm practicing strip tillage - are key components of the state's nutrient reduction strategy, said Jon Gallagher, a resource conservationist with the Linn County Soil and Water Conservation District, another sponsor.

Gallagher said the 10-acre shallow wetland west of Central City had been farmed until 2001, with inconsistent success. It now stores water running off 500 acres and filters nitrates from the water, he said.

Wetlands typically yield a 52 percent reduction in waterborne nitrates, according to Greg Brenneman, an agricultural engineer with Iowa State University Extension.

'In an ideal scenario we would have shallow wetland buffers all over the place,” Gallagher said.

Linn County Farm Bureau President Jason Russell, who finishes about 14,000 hogs per year near Prairieburg, said livestock producers manage manure in an environmentally responsible manner.

'We had 18 inches of rain in June, and we did not lose any manure,” he said.

Eight-foot-deep enclosed pits beneath the finishing buildings provide secure storage for at least a year, enabling the manure to be injected into the soil under ideal conditions, usually in the fall, he said.

Russell said the nutrient content of both the soil and the manure are tested to determine the optimal amounts to apply.

The manure is injected at least 4 inches deep into the soil 'not just to minimize the smell but also to prevent ammonia from escaping as a gas,” he said.

Zingula briefed tour members on a 17-acre field buffer complex consisting of grass and trees that he planted 16 years ago on a farm he rented south of Central City.

The vegetation, he said, virtually has eliminated soil erosion on land classified as highly erodible and has provided excellent wildlife habitat.

Ron Woeste, operations manager for Linn Co-op Oil Co., another of the tour sponsors, briefed participants on the variable rate technology used by 80 percent of the co-op's customers to optimize use of phosphorus fertilizer.

The system uses grid soil sampling and GPS technology to apply fertilizer at rates required for specific parts of fields, resulting in a 30 percent reduction in applied phosphorus during the past 20 years, he said.

Woeste also discussed the company's 'Balanced N” program, which uses multiple applications to reduce the risk of unused nitrogen leaching into water.

Brian Lensch, who farms northeast of Marion, explained his use of strip till cultivation, in which fertilizer is applied and corn seeds are planted between the rows of the preceding year's cornstalks.

Strip till, he said, enables him to plant corn year after year in the same field.

'With corn on corn, you have to get through the residue (of last year's crop),” he said. Strip till allows him to plant corn in corn residue without sacrificing most of the conservation benefits of minimum tillage, he said.

Brenneman said the goal of Iowa's nutrient reduction strategy - a 45 percent reduction in nitrogen and phosphorus loads - can be accomplished, but it will take time, money and a cooperative spirit.

'I learned a lot from the tour. I saw lots of beneficial practices,” said Rep. Art Staed, D-Cedar Rapids.

Staed said he thinks the state could do more to help fund conservation practices that would reduce nutrient pollution.

'The governor cutting funds set us back,” he said, referring to Gov. Terry Branstad's veto this year of $11.2 million for water quality and conservation programs.