Mark Muller: Brighter prospects for greener pastures

A fall vista of the Upper Mississippi River Basin.

A fall vista of the Upper Mississippi River Basin.

The past several years have put a spotlight on big challenges for water quality in the Mississippi River basin.

High prices, particularly for corn, have encouraged farmers to find ways to produce more. These days, U.S. farmers grow about 30% more corn than they did in the 1990s. To accomplish this, many farmers have taken fragile land out of conservation programs, and now till it for crop production. In the past seven years, enrollment in the Conservation Reserve Program has dropped nearly 10 million acres to currently about 26 million acres — roughly a 27% decrease in less than a decade. And although expanded crop production goes to a variety of end uses, well over two-thirds of U.S. corn goes to just two uses: feed for livestock and ethanol for fuel.

As McKnight’s newest program officer working to restore the Mississippi River’s water quality and resilience, I’m acutely aware of national attention to corn production’s impact on the river and community water supplies. Corn has a strong appetite for nitrogen, and the heavy loads of nitrogen fertilizer applied to corn too often end up in nearby bodies of water rather than in a corn plant. And lying beneath much of our country’s Corn Belt are perforated drainage pipes that drain snow melt and spring rain, bringing nitrogen-laced water into drainage ditches and creeks. Corn fields are also often heavily tilled, which can contribute to soil running off fields and muddying downstream lakes with habitat-burying sediment.

Using the same old practices to grow so much corn would keep the Mississippi River corridor in a constant state of defensive response — fighting to restore the water quality that we’re essentially trading for corn yields. But, happily, we also have many reasons to be hopeful.

Every year, more farmers emerge as key partners helping to address these issues, voluntarily participating in initiatives to protect soil and water. I have heard the term “soil health” more in the past few months than ever before. One step farmers are taking to improve soil quality and reduce runoff is minimal tillage, a method that minimizes soil manipulation by avoiding turning it over during tilling. More farmers are also embracing cover crops, which are crops grown between the rows of corn or soybean, or after the main crop is harvested — useful because they increase soil fertility and protect soils from heavy rains.

Austrian winter pea, one of several cover crops.

Austrian winter pea. (Photo courtesy Practical Farmers of Iowa, Counting Cover Crops report.)

I recently attended an agricultural field day on a farm near Northfield, Minnesota, organized by McKnight grantee Cannon River Watershed Project. At the gathering, a number of farmers talked about this past spring’s intense rain storms, and how they witnessed firsthand that fields with vegetation fared far better than fields that had been plowed clean. This growing interest in strategically using vegetation to protect fields is reflected in a recent National Wildlife Federation (also a McKnight grantee!) report Counting Cover Crops. At this point, cover crops are used on less than 2% of cropped acreage in the U.S., perhaps up to 4.3 million acres — and the number is growing.

And while corn will continue to be a crop of choice for Midwest farmers for the foreseeable future, exciting possibilities are emerging for perennial crops that provide enormous water quality benefits. Perennials are crops that don’t have to be planted every year and tend to provide more extensive soil-protecting root structures and ground cover. Many livestock and dairy farmers are building upon the practices of the past and are finding very productive and profitable ways of raising cows on grass (rather than on corn), and the demand for grass-fed products just keeps growing.

These emerging practices — with farmers at the center — are big steps, important steps. It’s getting easier to envision a future in which vegetable oils come from tree crops like hazelnuts, rather than soybeans, and bread comes from flour made from perennial grains that innovative crop breeders are actively working to develop.

Without question, recent findings like the Minnesota Pollution Control Agency’s documentation of high nitrate levels in streams and rivers in agricultural regions should give us all concern about the Mississippi River’s future. But the more we learn, the better equipped we are to respond — and many other trends offer good cause for optimism. By combining soil and plant research with conservation incentives and regulatory mechanisms, we may make the bare fields of late fall and early spring, and resulting pollution from them, a distant memory.

I’m hopeful that all of us working together to spotlight important connections between farming practices and water quality will lead to brighter days ahead.


MMullerMark Muller
Mississippi River Program Officer