Wet spring stresses Iowa farmland
Farmers, environment both suffering under record rainfall
The wettest spring in 141 years of record-keeping is testing farmers’ mettle and heightening the tension between agriculture and the environment.
With 12 percent of Iowa’s intended corn acreage and 56 percent of its intended soybean acreage yet to be planted, many farmers wonder if they will even have a crop to fret about in the heat of summer.
Many other farmers will have to replant crops that either drowned or failed to germinate in sodden and sometimes submerged fields.
Apart from the frustration and potential financial losses of unplanted crops, many Iowa farmers also have lost tons per acre of valuable topsoil as extreme rain events — ranging up to 8 inches in 24 hours — have carved gullies in highly vulnerable, recently tilled fields.
For Solon farmer Ed Ulch, whose family operation has 130 acres of planted corn under water, this sodden spring is nearly as bad as last year’s drought.
“The old-timers say the only thing worse than too much rain is no rain, and I’ll stand by that,” said Ulch, who will decide what to do with his flooded fields when the water recedes and they dry out.
“We are running out of time to replant corn, but we can still plant soybeans as late as July 1,” said Ulch, a 40-year farmer and a district director of the Iowa Soybean Growers Association.
Late planting risk
If it gets too late to plant soybeans, Ulch said he would consider filing a crop insurance claim under the “prevented planting” option — a last-resort that would pay him just 60 percent of the insured value of a planted crop.
Planting corn after June 1 is fraught with risk, said Bill Northey, secretary of the Iowa Department of Agriculture and Land Stewardship.
“When you reduce the total days the plant is in the ground, you face the prospect of reduced yields and immaturity at the end of the growing season,” he said.
Moreover, federal crop insurance coverage goes down 1 percent for each day corn is planted after an established cutoff date — June 1 in Iowa. The same reduction in crop insurance coverage applies for soybeans planted after June 15.
Unlike many Iowa farmers whose fields have been too wet to plant, Ulch said he was finished planting, although later than usual, when the Cedar River jumped its banks last week and flooded fields near Sutliff.
Planting progress has lagged far behind normal, at first because of soil too cold for seed germination during the state’s fifth-coldest spring, and then because of soil too wet for cultivation.
The statewide average March-through-May precipitation was 17.66 inches — 7.44 inches above normal and 2.3 inches above the old record established in 1892, according to State Climatologist Harry Hillaker.
The spring got wetter as it went along, culminating in a statewide average of 8.84 inches in May, beating the old record of 8.48 inches established in 1903, Hillaker said.
“There has been some significant erosion that varies a lot with the condition of the fields. You can see the real benefit of sound conservation practices and no-till crop production where those practices have been in place,” Northey said.
But those practices — such as grass waterways, field and stream buffer strips, and terraces — are not nearly as prevalent as they need to be to minimize soil erosion and water pollution, according to the Iowa Environmental Council, which, along with other conservation groups, has complained that farm field runoff has carried with it record levels of nitrogen fertilizer, the leading pollutant of Iowa waters.
Jim Grief, who farms 1,000 acres around Prairieburg, said he planted all his corn and most of his soybeans in four mid-May days, running two planters.
Most of his crops are in decent shape, but he will have to replant 120 acres of soybeans that failed to emerge from the cold, wet soil, succumbing to a condition called “damping off.”
Grief, the District 6 director of the Iowa Corn Growers Association, said his single biggest rain event, 3.5 inches in 48 hours, caused more soil erosion than he has experienced in many years.
While his grass waterways performed well, water washed away loose soil in recently strip-tilled fields, he said.
“Concentrated rain falling on saturated ground is a recipe for disaster,” said Linn County District Conservationist John Bruene with the U.S. Department of Agriculture’s Natural Resources Conservation Service.
The recent erosion, Bruene said, points out the areas where additional conservation practices are needed.
“Something should be there in those spots. A 30-foot-wide grass waterway would have saved a lot of soil,” he said.
Severe soil losses
While there is no accurate accounting of soil lost to erosion, Iowa State University Agronomy Professor Richard Cruse, director of ISU’s Iowa Daily Erosion Project, said he thinks Iowa soil losses in May likely constitute a record — an assertion he bases on record precipitation during a month when loosened soil lay exposed to the weather.
According to ISU’s erosion project, which estimates soil loss on the township level, using rainfall totals and the slope of the land in its computer models, May losses in parts of east-central and northwest Iowa topped 20 tons per acre — about four times the loss considered “tolerable” in an entire year.
Cruse said the ISU erosion project considers only sheet and rill erosion and does not take into account the more severe gully and channel erosion prevalent in many parts of Iowa this spring.
“Given the storms we’ve been seeing this spring, it is accurate to say we are underestimating soil loss from 30 percent to 50 percent,” Cruse said.
Removal of needed soil conservation efforts, like buffer strips, as well as the conversion of pasture and grassland to cropland, has accelerated the impact of recent rains, according to the Iowa Environmental Council.
Council spokesman Matt Hauge said the erosion is largely preventable. “We can’t stop the rain, but we can choose whether we will be prepared,” he said.
James Gillespie, director of the Division of Soil Conservation for the state agriculture department, said based on his personal observations that farm fields weathered the storms well where adequate conservation practices were in place.
“It was also evident that more grass waterways would have done some good in other areas,” he said.
Gillespie said he has also seen instances where terraces were overtopped by runoff.
“Some conservation practices have not been built to stand that amount of rain in that short of period,” he said.
Since April 1, that runoff has discharged about 185 million pounds of nitrate — with a commercial value of nearly $93 million dollars — into nine Iowa watersheds, according to Department of Natural Resources estimates.
The Environmental Protection Agency requires nitrate in drinking water be kept at less than 10 milligrams per liter to avoid potential human health problems.
Readings last month include 24 milligrams of nitrates per liter from the Raccoon River and 18 milligrams per liter in the Des Moines River, both water sources for the Des Moines water plant, which has had to activate its expensive treatment facility.The Cedar River reached one of its highest recorded nitrate levels, 18.5 milligrams per liter, upstream from Cedar Rapids, but the city’s drinking water, which is drawn from a series of wells, has been testing at about 7 milligrams of nitrates per liter.