River of Farm Waste

By no means has Minnesota ignored the tide of farm nutrients contaminating its waters. State authorities working with legislators and governors have responded over the last 30 years much like other farm states and the federal government – by building an unsteady foundation of policy and programs supported by considerable investments in science and administration. 

Minnesota monitors its surface and groundwater for nitrate contamination. It tracks the development of wells that draw large amounts of water. It developed a formal nutrient reduction strategy and a separate fertilizer management plan. University of Minnesota researchers publish peer-reviewed papers that identify sources of contamination and their consequences for drinking water and the environment. State leaders convene regularly in conferences with regulators, scientists, local officials, and community groups that focus on nutrient pollution.  

The investment in science and administration should set the state up for effective action. So should the more than $5 billion the US Department of Agriculture provides farmers in Minnesota and every other state for conserving resources and water. They include voluntary “best management practices” to impede nutrient runoff such as planting cover crops, cultivating buffer strips along ditches and streams, not plowing fields, and replacing cropland with meadows and pasture. 

Such practices were principally designed to slow soil erosion. They haven’t displayed much effectiveness in keeping nutrients out of water. And despite the taxpayer support most farmers don’t use them. The consequence is that halting contamination at the water’s edge, or into groundwater in Minnesota, has been elusive, to put it mildly. 

Just as in the other 10 Corn Belt states, Minnesota’s 25.4 million acres of farm land is deluged with fertilizer and ever more nitrogen-rich manure. Each year nearly 800,000 tons — 1.6 billion pounds — of commercial nitrogen fertilizer are applied on the state’s row crops, principally to grow 8 million acres of corn, according to state and federal figures. 

Livestock producers, who raise cows, cattle hogs, and poultry by the thousands in immense feedlots generate 49 million tons of nitrogen-rich manure. Minnesota’s hog population, now the second largest behind Iowa, numbers 8.9 million animals, more than double the 3.6 million pigs raised in the state 50 years ago.. 

There are no limits to the volume of nutrients crop farmer can apply, and scant regulation on spreading manure on farmland. Millions of pounds of nitrogen not absorbed by growing plants runs off fields into streams and lakes, or drains into groundwater. Across Minnesota, monitoring by state agencies has confirmed widespread contamination. From 2013 to 2019 the Minnesota Department of Agriculture tested more than 32,000 wells in 344 townships and found 9 percent contained nitrate levels over the safety standard. 

In a 2013 report the state Pollution Control Agency found excess concentrations of nitrate in 297 of the 728 streams – 41 percent – that it measured across Minnesota. The agency also reported that 158 million pounds of nitrogen drains from state farmland annually into the Mississippi River and is a primary cause of the huge dead zone where the river empties into the Gulf of Mexico. The Pollution Control Agency promised to develop an enforceable limit for nitrates in Minnesota surface waters. But that program was never completed.