What‘s Keeping Lake Erie Green? Part I: Agricultural Land Use in the Maumee River Watershed

Algal blooms in the Western Basin of Lake Erie occur annually, but public attention to their environmental and public health impacts has been diverted by the recent pandemic. Our Water Project Team examines different topics in this region related to the causes of algal blooms and efforts being made toward a solution. In this article, we take a look at crop land usage in the Maumee River watershed and its impacts on algal blooms. Cover image displays the Maumee River and its watershed from Google Maps satellite imagery.

Despite rather quiet media attention over the last six years, Lake Erie’s algae problem hasn’t improved since Toledo’s 2014 nationally-known water crisis; each summer, the water is as green as ever. After such a publicized public health emergency, one would expect consolidated efforts to mitigate the issue. And there have been on some level: city officials, farmers and environmentalists alike have advocated for better water quality. Yet many of the major factors for the bloom remain largely unchanged, one of them being agricultural land use in the Maumee River watershed. Ohio is a historically agricultural state, and much of its economic, cultural and social standing depend upon farming; thus, it is especially important to investigate and understand the complexity of the factors that lead to the algal blooms, and to work toward balanced solutions to mitigate negative impacts. 

Algal blooms in the Western Basin of Lake Erie are fed by excess phosphorus runoff from its many connecting tributaries in the U.S. and Canada. Nonpoint source pollution—runoff pollution that comes from many diffuse sources—contributes most of the nutrient pollution (phosphorus & nitrogen) into Lake Erie. Fertilizer and animal waste used in agricultural fields represent a significant portion of nonpoint source pollution. The Maumee River is one of the largest sources of nonpoint source pollution to Lake Erie, contributing almost half of the total phosphorus between 2011-2013. 

The Maumee River Watershed includes part of Ohio, Michigan and Indiana, which utilize large portions of their land for agriculture. The whole watershed drains over 4.2 million acres of land with roughly 72% of it used in agriculture. Major crops grown in the watershed include corn, soybean, hay and wheat. And among these, soybeans and corn are the most prominent, utilizing about 33-40% and 12-26% of land in the Maumee River watershed respectively within the past 10 years. Both require additional fertilization, with corn requiring the higher proportion of phosphate application: in a 2019 USDA report, the average annual phosphate application rates on soybean and corn fields were about 52 and 71 lbs per acre. Whereas phosphate was applied to about a third of all soybean fields, over 80% of corn fields annually receive phosphate application. 

Thus, the Midstory Water Project team looked at the agricultural land use for three major crops grown in the Maumee River watershed: soybeans, corn and winter wheat. We animated the crop-planting area in the watershed each year, using data maps from the USDA National Agricultural Statistics Service from 2010 to 2019. We also graphed phosphorus load from the Maumee River watershed, estimated using an analytical template and Maumee River watershed data from Heidelberg University’s National Center for Water Quality Research.

The majority of the Maumee River watershed is used for agricultural purposes, which leads to excess nutrient runoff into Lake Erie. Land usage has remained relatively steady over the last 10 years, so year-to-year fluctuations in crop land usage do not seem to have had a major impact on overall phosphorus load.
The majority of the Maumee River watershed is used for agricultural purposes, which leads to excess nutrient runoff into Lake Erie. Land usage has remained relatively steady over the last 10 years, so year-to-year fluctuations in crop land usage do not seem to have had a major impact on overall phosphorus load.

The phosphorus load into Lake Erie has fluctuated since 2010 due to a number of factors including but not limited to agriculture, precipitation and restoration of swampland.

In the past 10 years, the planting area of the major crops has remained relatively steady, with an increase of soybean growing from 1.382 to 1.671 million acres between 2012 and 2017. These increases and relative utilization of land for soybeans may be explained by a 27% price increase of soybeans in early 2012 from the previous year and increasing export demand mostly from China in following years. Between May and July of 2019, increased precipitation (24.3 inches of rain in 2019 versus a ten-year average of 18.7 inches) greatly disrupted planting in the Maumee River watershed. The USDA Farm Service Agency annually reports on the acres of land planted and prevented from being planted (often due to environmental circumstances). In 2018, the state of Ohio reported 24,756 prevented acres of corn (~3.4 million acres planted of corn) while in 2019, that number was over 37.5 times larger at 928,742 acres prevented. 

Phosphorus runoff depends on a number of factors, a major one of which is land use for agriculture. Crop coverage maps show that agricultural land takes up a considerable portion of land use in this region, but smaller fluctuations in yearly agricultural land use (considering the overall large amount of the watershed used for agricultural purposes) do not seem to be the most influential contributor to the amount of phosphorus runoff to the lake, which suggests that how we manage the use of existing agricultural land is key to mitigating the algal bloom issue. For example, even though in 2019, the crop planting area was dramatically reduced due to precipitation, the phosphorus runoff was the third-highest year in the past 10 years. The severity of Lake Erie’s algal blooms aren’t as simple as they seem, with many factors impacting the runoff going into Lake Erie, including levels of precipitation, application of fertilizer on crop lands and conversion of swamp lands. That’s why, in the coming installments, the Water Project team will tackle additional factors

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Recent Articles

Charity Appeal: Celebrity Influence in Times of Crisis

It might seem counterintuitive that entertainment and cultural icons thrive during tremendous times of hardship, but history has proven it true. 

Entropic Peace in Isolation: Revisiting Yayoi Kusama’s Fireflies on the Water...

The Toledo Museum of Art exhibition program brought together a special presentation of Yayoi Kusama’s Fireflies on the Water installation, just for a global pandemic to hit soon after. Despite what seemed to be a major set-back, COVID-19 has instead transformed Fireflies on the Water into a deeper reflection into what isolation and the individual mean in the chaos of 2020. What was once an incomprehensible escapist dream is now a sober dissolution into universal existentialism.

The 2020 Election Dilemma: How Ohio has Handled Voting During the...

The 2020 presidential election stands to be one of the most complex and highly anticipated U.S. elections in recent history, primarily because...

Sustained Outrage in the Fight Against the Opioid Epidemic: A Review...

Pulitzer-prize winner Eric Eyre’s new book exposes how hard drug distributors work to keep eyes off of their numbers and how important it is for journalists to keep looking. In the small towns of America, it can literally mean life or death. The opinions expressed in this series are those of the author and do not necessarily reflect any official organizational stance. Cover graphic by Ruth Chang for Midstory.

Bringing Home the Bacon: A Review of Okja

The world seems to be growing increasingly complicated, as evidenced by the past several decades, years or even months of—well, everything. And with more problems come more proposed solutions; how do we solve the coronavirus pandemic, systemic racism, political division or world hunger? But behind every solution is a who, a what and a why. This is exactly what South Korean filmmaker Bong Joon-ho confronts us with in his Netflix original Okja: as an egotistical CEO hailing from a powerful family proposes to solve world hunger with a new species of super-pigs bred for their meat, complications soon arise that question the validity of such a solution, as well as whose problems it ultimately solves.

Recent Videos

COVID-19 Risk Assessment for Ohio: Identifying Risks for Ongoing Reopening and...

As our researchers watched Ohio’s response to the pandemic, they wished to contribute meaningfully toward the next stage of disaster response and help to prepare our state for future crises. This risk assessment brief is a comprehensive look, county by county, of factors that put Ohio’s populations at risk for COVID-19, including socio-economic status, mobility, race, overcrowded housing and more.

Film, Storytelling & the Midwest: A One-on-one with Brandon Li

The Midstory Team chats with Brandon Li, a travel videographer, about his unique style of filmmaking, the impacts of the pandemic on the travel and videography industry and his perspective as a nomad who grew up in and left the Midwest.

Public Libraries: Reopening & Addressing Social Inequities

The Midstory Team chats with Jason Kucsma, the director of the Toledo Lucas County Public Library, about the evolving role of the libraries during the crisis, the move of library resources toward digital infrastructure and considerations on policies for reopening.

What We Can Learn from Taiwan’s COVID-19 Response

The Midstory Team chats with Dr. Shao-Hsuan Hsia, the director of the Division of Pediatric Respiratory Therapy and the Chief of the Pediatric Intensive Care Unit at Chang Gung Memorial Hospital in Taipei, about Taiwan's response to the pandemic, social responsibilities and the state of public health in Taiwan.

Art & Resiliency: Museums in the Age of COVID-19

The Midstory Team chats with Adam Levine, the director of The Toledo Museum of Art, about the future of art and museums, including the role of digital presentation, utilization of outdoor spaces and shifts in artistic expression in times of crisis.