Severe erosion and lack of conservation progress cause for alarm among Iowa experts

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Former Iowa Environmental Council executive director Linda Appelgate captured this image of a corn field eroding into the Nishnabotna river in 2010. According to the Iowa Farm and Rural Life Poll, nearly 80% of Iowa farmers agree they need to do more to “reduce nutrient and sediment runoff into streams and lakes.”

Last week was Soil and Water Conservation Week in Iowa, a time to reflect on how well we are protecting one of Iowa’s most precious natural resources.  Unfortunately, soil erosion remains a serious problem in our state. Recently several top experts on Iowa soil conservation weighed in and expressed alarm about the state of our soil.

The Iowa Daily Erosion Project can create estimates of soil erosion the morning after a rainfall event occurs.  Here, estimates are shown for a 2-day precipitation event on April 12-13, 2014.  Still, without advances in modeling, project manager Rick Cruse says these models do not tell the whole story of Iowa soil erosion.

The Iowa Daily Erosion Project can create estimates of soil erosion the morning after a rainfall event occurs. Here, estimates are shown for a 2-day precipitation event on April 12-13, 2014.   Still, without advances in modeling, project manager Rick Cruse says these estimates do not tell the whole story of Iowa soil erosion.

Most unsettling was a reminder from Iowa State University agronomist Rick Cruse that our present methods of estimating soil erosion are badly flawed and may be missing between 20 and 90% of the erosion in the state.  In total, Cruse estimates the economic harm to agricultural yields Iowa suffers from historic soil erosion may be as great as $1 billion each year–harm that will grow as erosion continues.

Cruse, who manages the Iowa Daily Erosion Project, said current models only account erosion that occurs evenly across the soil’s surface and fail to account for ephemeral gullies that form when heavy rainwater forms channels and washes out a trench along a slope.  He answered questions about soil erosion recently in the Des Moines Register and spoke about his research at length in an Iowa Learning Farms webinar, which is available free online.

Cruse’s work to uncover the true extent of Iowa soil erosion has made headlines before when the Environmental Working Group used Iowa Daily Erosion Project estimates to show that some parts of Iowa suffer soil erosion rates 12 times the rate the government considers “tolerable” in a report titled Losing Ground.

As the Register reported Sunday, the more accurate soil erosion estimate Cruse is developing now “is expected to paint an even grimmer picture of Iowa’s soil erosion.”

And Cruse is not the only expert sounding an alarm.  In a recent column published by the Leopold Center for Sustainable Agriculture, Jerry Hatfield, Director of the National Laboratory for Agriculture and the Environment, based in Ames, wrote that “If we could hear soil biological systems, I am sure we would hear them screaming.”

Hatfield decried what he called “disturbing trends in our attitudes” about soil and increasing complacency with heavy erosion rates.  He cited research indicating a strong relationship between soil health and crop yield and called for stronger action to protect healthy soil systems.

In a recent piece in the journal Environmental Science & Technology, Jerald Schnoor, a professor of civil and environmental engineering at the University of Iowa, picked up the story, explaining how bare soils left exposed to heavy spring rains lead to substantial loss of nitrogen and phosphorous into Iowa’s waterways, a situation the Iowa Environmental Council chronicled extensively last spring.

Schnoor took a position in support of science-based nitrogen and phosphorus criteria along with enhanced conservation programs to achieve change where it is most needed.  He wrote:

“Today, the situation has become untenable. EPA strongly encourages Iowa and other agricultural states to adopt water quality criteria for nutrients, but the scientifically determined criteria are more stringent than the quality of most waters in the state. How does one admit that virtually every waterway in the state does not meet designated uses for aquatic life and is “impaired” requiring management action?

“In reality, Iowa is simply a poster child for a national problem that will require the same type of resolve and investment that we made for point sources through the Clean Water Act.”

For our part, the Iowa Environmental Council supports the adoption of water quality standards for nitrogen and phosphorus similar to what Schnoor proposes, as well as enhanced, targeted conservation action.  If adopted, the water quality standards would serve as clean water goals to help conservation efforts around local lakes and rivers succeed.  Since Iowa first released its current plan for water pollution reduction, the Iowa Nutrient Reduction Strategy, we have called for development of timelines, milestones and measures of success necessary to assure Iowans their water will be cleaner over time.

Iowa’s scientific community is increasingly united concerning the severity of our state’s conservation challenge and what strategies are needed to address it. The public is behind efforts to reverse the loss of our soils—the sense of urgency among all stakeholders is missing, however.   In the end, we at the Council can only agree with one of Dr. Schnoor’s concluding thoughts, “I wish we could get down to business.”

Extract from Dr. Schnoor’s piece is reprinted with permission from Environmental Science & Technology 2014 48 (9). Copyright 2014 American Chemical Society.

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One response to “Severe erosion and lack of conservation progress cause for alarm among Iowa experts

  1. Pingback: Cruse and gully erosion in the spotlight | Iowa Learning Farms