Soil erosion increasing
Marathon County farmers are using more environmentally friendly methods of tillage, but, given the increase of row crops and the decrease in acres of forage, county farmland erosion rates are increasing.
That’s according to county land and water program manager Paul Daigle who on Thursday updated the Environmental Resource Committee on cropping practices in advance of a yearlong effort to draft and pass a county land and water plan. Daigle said farmers were trending away from conventional tillage, preferring instead to leave mulch residue on their fields. He said, too, that five percent of county acres are now farmed with no-till methods.
Yet, the switch from growing hay for dairy cows to raising row crops, including corn and soybeans, is leading to more tons of soil leaving the landscape and winding up in surface water, Daigle said.
He said farmers in Marathon County in 1999 lost an average of 1.6 tons of soil per acre of farmland. In 2018, the soil loss was 2.5 tons per acre.
The manager said the higher loss of soil is bad for the environment, but it meets state performance standards. Tolerable soil loss, he said, is 3.7 tons per acre.
Daigle said there has been a significant shift in what farmers grow. Back in 1999, he said, three percent of county acres were planted in soybeans, but now 17 percent are. Likewise, farmers planted a quarter of their farmland
With added acres of soybeans and corn, more county soil loss
with corn in 1999, but now that percentage is 33 percent. Land dedicated to hay production has decreased from 53 percent in 1999 to 41 percent in 2018.
“We are seeing more erodible types of crops being planted,” he said. ”We have a higher percentage of acres being tilled.”
Daigle said farmland erosion rates east of the Wisconsin River were relatively low, between 0.6 and 2.4 tons per acre. Erosion rates west of the Wisconsin River were higher and, in some areas, push up against the legal tolerable soil loss standard. Soil loss in the Edgar, Marathon and Mosinee areas range from 2.4 to 2.1 tons per acres. Soil loss in the Athens, Stratford and Fenwood areas range from 3.1 to 3.4 tons per acre. The county’s highest erosion rates are 3.6 tons per acre in the towns of Hamburg, Stettin and Berlin.
Daigle said some farming operations run the risk of not being in compliance with state regulations.
“We are still pushing that edge,” he said.
Daigle said his statistics are gathered in a soil erosion transect survey, a biannual study taken in June. The survey documents crops and tillage at 682 stop points across a 604 mile route all over Marathon County. Each county township is traversed at least twice. Data from the survey is fed into a Snap-Plus computer modeling program.
MARATHON COUNTY EROSION RATES 2018 (TONS PER ACRE)
