Archive Hosted by the AFL-CIO

The Environmental Costs of Abundance

May 19, 2014 By Kira Liu, Macalester College

Today Minnesota 2020 continues a series of columns focusing on agricultural and biodiversity issues. This is part of a continuing collaboration with Macalester College's Geography Department and its students.

Far more nitrate contaminants in our drinking water actually come from agriculture than industrial pollution. In 2013, the growing crop yield increased use of inorganic fertilizers on conventional, monoculture farms.

The fertilizer runoff from farms in Minnesota and many other regions along the Corn Belt has increased the levels of nitrate in surface waters, posing threats to the health of the environment and to humans and animals. About 80-95% of the nitrate in surface waters of the Minnesota, Missouri, and Cedar Rivers and Lower Mississippi River basin comes from cropland.



High levels of nitrate can become harmful to humans when they permeate drinking water wells. In Minnesota, about three fourths of people get their water from groundwater wells, although the intensive nitrate problems are concentrated to specific areas: Dakota and Washington counties, the southeast “karst” region, the multi-county Central Sands region northwest of the Twin Cities and parts of southwestern Minnesota.

Nitrates are especially harmful to pregnant women, and children under the age of one. Infants under 4 months lack an enzyme needed to correct the restriction of oxygen transportation in the bloodstream, which is caused by nitrates in the water, a condition called blue baby syndrome. Without immediate actions, nitrate levels will only increase.

High nitrate levels also can harm fish and aquatic life when the run off enters lakes or rivers. Nitrates in the Mississippi River are one of the causes for the oxygen deprived “dead zone” in the Gulf of Mexico, which is currently the size of Massachusetts. Excessive nitrogen in water can speed up the growth of algae, which clogs water intakes and uses up most of the dissolved oxygen in the water as they decompose. The deprivation of oxygen in water is detrimental to fish populations and effects our fishing industry as well. Inorganic fertilizers cause more harm than to just the farms they are applied to, and environmentalists and farmers should be working together to develop more sustainable programs.

Nitrate based fertilizers not only affect the long-term fertility of soil, but the runoff from farms impacts a larger area then just the farm itself. These inorganic fertilizers do not actually enrich the soil long-term; they only affect the current crop. While there are quality standards for human drinking water in terms of nitrate concentration, these do not exist for livestock, in particular ruminant animals like cows and sheep. High concentrations of nitrates in both water and feed in animals can lead to sickness and even death, affecting the meat and dairy industries. Fertilizers are not the solutions to our global food issues, if anything they are delaying modern sustainable practices by weakening the health of our food systems.

The U.S. Department of Agriculture launched a new initiative in 2010 to develop a more rigorous monitoring of nitrate levels in groundwater. As nitrate levels rise, so does community awareness about rules of nitrate use. The problem however, is that this doesn’t apply to all regions. In Eastern Dakota County there are no laws for the people to follow, the communities are on their own to solve the growing nitrate problem. While testing water for nitrate contaminants is relatively simple, it requires a laboratory and the Minnesota Department of Agriculture does not offer any guidelines for self-testing.

Not only are nitrate levels an issue in Minnesota, but all across the corn-belt of America. The Midwest is at a significantly higher risk of nitrate contamination in shallow groundwater. This ties directly to the high levels of conventional agriculture occurring in these high-risk states. While many crops naturally need nitrate to survive, extensive monoculture can deplete the soil of its natural nitrogen sources and farmers then justify the use of fertilizer to keep up with production rates for our growing population. However, alternative methods of farming have been shown to keep up production without sacrificing health and sustainability.

One method in particular is polyculture, or multicropping. This system works to plant multiple species on one piece of land, which increases biodiversity, crop yield, and helps to rejuvenate the soil, especially through natural nitrogen fixation and reduced use of heavy machinery. However, changing the nature of our farms to polyculture is a daunting task, and there are alternative, more practical approaches to more environmentally friendly farming. One option is to use organic fertilizers, which provide nutrients for the soil, and are not detrimental to the long-term health of people and the environment. Modern techniques have also been developed, like precision farming, to apply only necessary quantities of nitrogen to the soil to avoid run-off.

The Star Tribune quotes Kris Sigford, the water quality program director for the Minnesota Center for Environmental Advocacy. He states “dramatic impacts to our waters from nitrate loads can only be addressed by large landscape-level changes to agricultural practices and cropping systems.” In order for change to happen, we must focus on changing the way we farm. We are now seeing the impacts of inorganic fertilizer use in our everyday lives. To change the health of our people and our environment we must start with a change in our agriculture systems.

Thanks for participating! Commenting on this conversation is now closed.