Trying to keep central Illinois fertilizer out of the Gulf

Last August the National Oceanic and Atmospheric Administration announced the Gulf of Mexico “dead zone” – an area of low oxygen (hypoxia) that can kill fish – is the largest ever measured. At 8,776 square miles, it is an area about the size of New Jersey. Scientists have determined that the dead zone is caused by nutrient pollution, primarily from agricultural and developed land runoff into the Mississippi River. Central Illinois contributes more than its share, with University of Illinois researchers concluding in 2015 that agriculture contributes 80 percent of the nitrate-nitrogen that flows into the Mississippi from Illinois. “The tile-drained areas of central and northern Illinois are the largest source of nitrate,” says a government report. As they say, we have met the enemy. … Concern about the dead zone has spawned the Mississippi River Gulf of Mexico Hypoxia Task Force, the Illinois Nutrient Loss Reduction Strategy Policy Working Group, the Illinois Best Management Practices Council and a dozen other groups and task forces geared toward keeping fertilizers and pesticides in soil and out of lakes and rivers. The busiest group close to home is the Lake Springfield Watershed Resource Planning Committee. Last week Barbara Mendenhall, manager of the latest EPA grant to improve water quality in the Lake Springfield watershed, was implementing the group’s latest big idea for moving soil conservation from theory to practice – a first-time “ladies-only” meeting of women landowners. Ranging in age from 30 to 90, the widows, wives, heirs and some active farmers were “tickled to death” to get their questions answered without men around to dominate the discussion. “Women tend to be more conservation-minded,” Mendenhall said, but they’re usually not the ones to implement the strategy. So some of the talk was about how to get the men who rent their ground to do what they want done.

“We discussed the benefits of soil health, water quality and the responsibility of farmland owners for the land,” Mendenhall said. A field trip showed conservation tillage operations, grass waterways, crop rotation and applying nitrogen with a strip bar so the fertilizer goes only to the row where the seed is planted. Where cover crops had improved soil health, a shovelful of dirt revealed happy earthworms.

Mendenhall went to work for the Sangamon County Soil and Water Conservation District in 1989, later serving 15 years as executive director before retiring four years ago. She’s seen progress in her nearly 30 years of promoting soil conservation. “When I got involved it was deep tillage,” she said, but now farmers know to leave crop residue over the winter to provide the soil some protection. Just 10 years ago, farmers would apply nearly all their nitrogen in the fall, while now many apply half in the fall, the rest in the spring, sometimes side-dressing with nitrogen after the corn is up. Under the EPA grant that Mendenhall administers, farmers can apply and receive a site-specific nutrient management plan, based on soil tests and prior yields. All the practices are geared toward getting the biggest bang for the fertilizer buck, which also keeps fertilizer out of waterways.

Grants also pay for cover crops, which not only hold soils in place after corn and soybean harvests, but also add organic matter, increasing microbial biomass and aiding water retention. Last year EPA grants, matched by Springfield’s City Water, Light and Power, helped farmers in the Lake Springfield watershed plant 1,572 acres of cover crops, and another 450 acres will be added this year – about 2,000 acres total this year. That may sound like a lot until you consider the Lake Springfield watershed includes 125,000 acres of farmland.

Are we making any progress? “It’s too soon to tell,” said Ted Meckes, CWLP water division manager for the past six years. He, like Mendenhall, has been fighting the uphill battle of protecting Lake Springfield since the 1980s. The lake is “silting in at a slower rate,” he says wearily. “This didn’t happen overnight.” Besides soil conservation measures, Lake Springfield is helped by being fed by small tributaries rather than a river. The Illinois State Water Survey estimates Lake Springfield will lose only 2 percent capacity per decade through 2050 from sediment deposition, compared to Lake Decatur, which is silting in at 5.5 percent per decade and Lake Vermillion at 8 percent.

“We see good things happening, though not as fast as we want them to,” says Barb Mendenhall. According to last year’s Lake Springfield Watershed Management Plan, still about 74 percent of the watershed’s 125,000 acres of cropland is still farmed using conventional tillage methods, rather than no-till or conservation tillage. “That’s a high percentage. Those who farm a lot of acres find the quickest way to get the crop in is to till.”

She sees structural problems in the farm economy that bode against best management practices. She said many farmers used to have a 50/50 crop share lease, where the landowner paid half of the costs in exchange for half of the crop. Now most pay straight cash rent, which makes the farmer responsible for all the inputs, the equipment and the rent. With low commodity prices, farming is a “very stressful occupation these days,” she said. No wonder expensive niceties like cover crops and grass waterways don’t happen unless the government provides more grants. Talk is that conservation programs could take some deep cuts in the federal farm bill now under discussion in Washington. “I’m not liking what I’m hearing,” says Mendenhall.

Nevertheless she and many others persist, preaching the message of healing the soil. “We’re continuing to go after grants at every opportunity,” she says. There will be informational meetings on best practices every December and February, and a Lake Springfield watershed tour will show farmers where progress is being made. As Mendenhall says, “Many are trying to do the right thing.”

Fletcher Farrar manages a southern Illinois cattle farm, which presents different erosion problems than central Illinois cropland, but where soil health management is also the key to the future. Contact him at [email protected].