A fish kill was found in Wolf Creek in Tama County last week, after a manure applicator for Mayo Farm Inc. reported that about 2,600 gallons of manure leaked had from a drag hose. The applicator attempted to stop the flow, but estimates that up to 500 gallons reached the creek. Environmental officials from the Iowa Department of Natural Resources are investigating the spill.
Fresh manure contains ammonia, which kills fish at high quantities. Manure is used as a fertilizer because of the high levels of nutrients ‒ notably nitrogen and phosphorus ‒ that it contains. However, when too much of these nutrients enter an ecosystem, it can throw the system out of balance. Algae tends to bloom in nitrogen-rich environments, and certain types known as cyanobacteria can be toxic for aquatic life.
Even when it isn’t toxic, overgrowth of algae can also kill fish through oxygen depletion, known as hypoxia. Nitrogen runoff from Iowa agriculture contributes not only to local hypoxia, but also to the largest ever “dead zone,” at the basin of the Mississippi River in the Gulf of Mexico. The voluntary practices recommended in the state’s 2014 Nutrient Reduction Strategy include reducing the use of fertilizers in order to reduce hypoxia.
Agronomy researchers at Iowa State University have proposed ideas for an ambitious and much-needed update to Iowa’s agricultural drainage system. Their study makes suggestions for mitigating the effects of altered precipitation patterns due to climate change while reducing pollution to air and water.
The concept of “sustainable intensification” (the authors define this as “producing more food from the same amount of land with fewer environmental costs”) is at the core of the research. ISU agronomist Michael Castellano led the study in partnership with University of Kentucky and the Swiss Federal Institute of Technology ETH-Zurich.
Artificial drainage systems are comprised of underground pipes, tiles and drains that move water off farmland, discharging it into ditches that flow into natural surface waterbodies. Without this network, most of Iowa’s land would be too waterlogged to farm, but drainage systems increase runoff of nutrient and bacterial pollution from fields into waterways.
The increasing frequency of both intense rain events and draught in Iowa due to climate change is also putting extra pressure on those systems, which were designed before Iowa agriculture became so intense. The study, published in Nature Sustainability, describes several solutions. “Controlled drainage,” or installing gates that can temporarily open/close at the ends of drains, could allow farmers to increase drainage during wet springs and retain more water during dry summers.
Installing narrower, shallower drains could further reduce nutrient concentration in drainage water, the authors claim. They say it could also reduce needed fertilizer inputs and decrease greenhouse gas emissions from the soil.
The study also describes the need to increase on-farm conservation practices, like returning some farmed land to wetland, in conjunction with updating infrastructure.
The Conservation Districts of Iowa passed a resolution earlier this month calling for mandatory buffers to protect the state’s water by prohibiting crops from being planted within 30 feet of a stream. These buffers protect waterways from erosion and nutrient pollution, and also promote biodiversity by preserving habitats.
The Conservation Districts of Iowa, or CDI, is made up of 500 soil and water conservation district commissioners, elected from each of the soil and water conservation districts in the state. The group’s purpose is to promote conservation practices and policy, and they now plan to lobby the Iowa Legislature on this issue, hoping to pass a law to make buffers mandatory. Minnesota passed a law requiring buffers of 50 feet, and now has a 96% compliance rate.
A similar resolution failed to pass the CDI last year. Laura Krouse, one of the commissioners who proposed the resolution, credits the change in opinion to the heavy precipitation and flooding that the state has experienced over the past year, which hurt farmers across the state. Many farmers already plant perennials around streams, but others don’t, and farmland regulations are expected to meet resistance.
Opposition Secretary Mike Naig of the Department of Agriculture and Natural Resources said that he opposes making buffers mandatory, preferring voluntary, incentive-driven programs. Krouse responded that Iowa has, “relied on the voluntary approach for 70 years. It’s not working in some areas.”
“There’s too much at stake to bet on voluntary practices,” the plaintiffs wrote in an op-ed for the Register. “We want to force elected officials to think about a food and farm system that works for farmers, workers, eaters and the environment, not just industrial interests.”
Runoff of fertilizer and manure from farms contributes to harmful algae blooms, which leech toxins into local waters and create a lifeless Dead Zone in the Gulf of Mexico. The environmental groups say the state has failed to uphold the “Public Trust Doctrine,” which states that the government must protect certain natural resources for public uses, like drinking and recreation. As of now, tried-and-true nutrient reduction strategies like planting cover crops are incentivized but not mandated for farmers.
Others, like the Iowa Soybean Association CEO and the Secretary of Agriculture Mike Naig, told the Register the “potentially divisive” lawsuit disappointed them. For many, this case recalls the 2015 Des Moines Waterworks lawsuit against drainage districts in three north Iowa counties, which attempted to force compliance with federal clean-water standards for “point-source” polluters but was ultimately dismissed.
The public rarely gets its science straight from the source; we depend largely on the media to distill complicated academic research for us. University of Iowa researcher and adjunct professor Chris Jones is one of a rare breed of scientists who can adeptly communicate science on his own.
Jones has spent his career monitoring and researching the Iowan environment for institutions ranging from Des Moines Water Works to the Iowa Soybean Association. As an IIHR research engineer today he conducts original research and runs a blog where he explores the systems and nuances surrounding Iowa’s degraded water.
Recently, Jones calculated “Iowa’s real population” based on the nitrogen, phosphorus and solid matter in animal waste. He explained that Iowa’s millions of hogs, cattle, chickens and turkeys produce as much waste as 134 million people. The map pictured above matches the human populations of global cities and U.S. states to the “real populations” of Iowa’s watersheds.
“Managing the waste from these animals is possibly our state’s most challenging environmental problem,” he wrote. Weather and plant life cycles create a limited time window to apply it to fields, and hauling and handling it presents other challenges. When nutrients from manure enter waterways, they contribute to harmful algae blooms locally and in the Gulf of Mexico.
In another recent post, Jones used public data to compare the amount of nitrate purchased commercially and produced via manure in each Iowa watershed with the Iowa State University recommended application rate for corn. He found that, on average, Iowa farmers over-apply synthetic nitrogen by 35 pounds per acre. The addition of manure brings that surplus to 91 pounds per acre.
Other posts explore historical, social and political angles. Earlier this week, a post called “Ransom” related efforts to protect Lake Eerie in Ohio to the economic reality of farming and agribusiness in Iowa. “Who is getting the outcomes that they want from our policies, and in particular, the old school policies targeting improved water quality?” Jones asked.
Overall, Jones’ blog offers an informative and rather accessible expert perspective on a hugely complex issue. To subscribe yourself, visit here and enter your email at the bottom of the left sidebar.
***In an earlier version of this post, the number “134 million” was incorrectly written as simply, 134. Big difference! Thanks so much to those who pointed out the error***
In light of upcoming midterm elections, Popular Science wants voters to be informed about science policy, even if campaigners are not. The national magazine recently released a list of each U.S. state’s most pressing science policy issue.
Unsurprisingly, Iowa’s biggest challenge is to reduce pollution from farms. Because intensive agriculture takes place on over two-thirds of Iowa’s land, nutrients like nitrogen and phosphorous leak from the state’s ubiquitous farm fields into waterways at alarming rates.
The list cites a University of Iowa study from earlier this year, which found that Iowa’s nitrogen runoff into the Mississippi River rose 47 percent over the last five years. The Iowa Nutrient Reduction Strategy, initiated in 2013, aimed to reduce this rate 45 percent in that same time span.
Nutrient loss degrades soil quality for growers, and has created legal tensions between farmers and local waterworks. The loss creates issues far downstream as well. An overabundance of nutrients in the Gulf of Mexico has created a “dead zone” where low-oxygen conditions are inhospitable to aquatic life, which threatens the area’s fishing industry.
The Nutrient Reduction strategy pushes conservation practices like planting cover crops on otherwise bare fields, diversifying land use, and creating buffers along waterways out to farms, but adoption of such practices is still too low.
The next round of political leaders will need continue searching for a solution, something Iowa voters should take into consideration. As Popular Science wrote, “Even if it never surfaces on the campaign trail, science is always on the ballot.”
Scientists who have been working to curb nutrient runoff in Iowa’s waterways since 2010 through the Nutrient Reduction Strategy have publicly estimated that it would cost billions of dollars to adequately address Iowa’s water quality problem. Senate File 512 falls short, allocating $282 million to water quality improvement over the next twelve years. The plan draws money from an existing tax on tap water that used to go into the state’s general fund and gambling revenue that was once used for infrastructure projects.
Republican John Wills of Spirit Lake spearheaded the bill’s passing. According to the Register, he said, “The bill builds upon the successful implementation of the Iowa Nutrient Reduction strategy and provides for long-term and sustainable funding. This is just the beginning, not the end.”
While the measure passed the House of Representatives 59-41, both Republicans and Democrats criticize the bill for not going far enough to clean up Iowa’s nearly 700 impaired waterways. Republican representative Chip Baltimore of Boone, Iowa said “I don’t know about all of you, but I did not come down here to check a box. Just because the words ‘water quality’ are in the title of a bill does not make me proud to vote for it so that I can put it on a postcard when I go campaign.”
Iowa’s largest environmental coalition, the Iowa Environmental Council, released a statement criticizing the bill. In the statement, the organization’s Executive Director Jennifer Terry, said, “Our legislature today chose a failed business-as-usual approach to cleaning up our polluted lakes and rivers.” She continued, “The legislation passed today lacks a scientifically-proven watershed approach, lacks funding for adequate financial and human capital, lacks required water quality monitoring or assurance of public access to data about Iowa’s water quality.”
The coalition calls on Republican Gov. Reynolds to veto the bill.