by Jason Johnson, Public Affairs Specialist, USDA-Natural Resources Conservation Service, Des Moines, Iowa
Even though Frederick Martens’ grandfather started farming his Madison County ground more than a century ago, Martens continues to implement the latest in conservation technology to sustain the family farm for at least 100 more years.
Martens operates the 1,300-acre farm on his own after his father retired following the 2015 harvest. His operation includes a corn, soybeans and hay rotation. He also leases 300 acres of pasture on the western edge and headwaters of the Badger Creek Watershed.
Martens and his father, who goes by the same name, have worked closely with USDA’s Natural Resources Conservation Service (NRCS) and state and local conservation groups the past several years to apply practices that will reduce sediment runoff and nutrient loading to Badger Creek Lake.
Badger Creek Lake is listed on the Iowa Department of Natural Resources’ (DNR) 303(d) list of impaired waters due to excessive siltation and nutrient loading. “When Badger Creek was added to the impaired waters list, I felt bad,” said Martens. “This is a Century Farm and I want to keep it up as good or better as I inherited it, and in good shape for the watershed, too.”
The CREP wetland is strategically located and designed to remove nitrate from subsurface tile-drainage water flow. “It is the perfect location for a wetland because it helps denitrify water flowing from nearly 700 cropland acres around it at the headwaters of the watershed,” said Badger Creek Lake Watershed Project Coordinator Anna MacDonald.
Water quality research by Iowa State University confirms that CREP wetlands can remove up to 90 percent of the nitrate and herbicide in tile drainage water from upland crop ground.
A year after the Martens family installed the wetland NRCS selected Badger Creek Watershed as one of five Iowa watersheds to be part of the National Water Quality Initiative (NWQI). The program offers higher than typical financial assistance to farmers in the watershed to install conservation practices that control and trap nutrient and manure runoff. Martens viewed it as an opportunity to try some new approaches to soil and water conservation.
“Our family has farmed here for more than 100 years, and the rainfall events the last few years have been stronger and harder than I ever remember,” he said. “We had gullies showing up in places we had never seen them before.”
In 2013, Martens added 6,900 feet of terraces with assistance through NWQI. He said the farm now has more than 20,000 feet of terraces, which reduce erosion by shortening slope length and defining the contour for row-cropping. “We have about all of our hilly areas lined with terraces now,” said Martens.
To provide even more protection from erosion, MacDonald recommended Martens add cover crops to his farm’s suite of practices. Cover crops such as cereal rye, oats and radishes can be planted to temporarily protect the soil from erosion and supply living roots to the soil during times when cropland is often not adequately protected.
Martens took a conservative approach by planting 58 cover crop acres his first year. By the second year he planted 87 acres, and in 2016 he seeded a total of 150 acres of cover crops. “This year I aerial-applied cereal rye and radishes into corn, and oats with radishes and turnips into soybeans,” he said.
“I’m anxious to see the organic matter content in these fields once they are sampled to see if there is an increase,” continued Martens. “I also don’t see many weeds in my fields with cover crops, so I think they do a good job controlling winter annuals, if not more.”
Martens is just one of a couple dozen farmers in the watershed who have tried cover crops, along with many other practices to protect the water quality through USDA’s NWQI funding. MacDonald says the project goal is to reduce sediment and phosphorus from leaving the land and entering the lake. “There are many different practices to address that goal, but no silver bullets,” she says. “However, we have been promoting cover crops because they go hand-in-hand with other practices such as no-till and reduced tillage, terraces, and grassed waterways. Like those practices, cover crops can help prevent erosion, but it’s the additional benefits like retaining nutrients, building soil tilth, and providing forage for livestock that really make cover crops a win-win practice for farmers and the lake.”
“The Iowa DNR would like to do extensive restoration work in Badger Creek Lake, but it’s important that we are making progress toward our goals for sediment and phosphorus reduction in the watershed before that begins,” said MacDonald. “The lake’s impairment is the result of soil loss from many farms over many years, so to change that we need to save soil on every farm in the watershed.”
For more information about conservation planning and programs to help you treat the natural resource concerns on your farm, visit your local NRCS office or go online to www.ia.nrcs.usda.gov.