For the Bay: Chesapeake nutrient imbalance must be addressed

January 18, 2011

University Park, Pa. -- The problem plaguing the Chesapeake Bay is widely known and obvious, according to a crops and soils expert in Penn State's College of Agricultural Sciences. But after decades of trying to save the famous estuary by spending billions of dollars on pollution-control measures, we have made a lot of progress but we still have a long way to go to solve the problem.

The bay watershed is out of balance, noted Doug Beegle, distinguished professor of agronomy. Simple to say, easy to see -- devilishly difficult to fix in today's world. And while agriculture is not entirely to blame -- excess nutrients also are coming from sewage-treatment plants and urban runoff -- about half of the problem involves farm fields and agricultural facilities.

Simply put, too many nutrients are brought into the Chesapeake drainage in the form of grain from places like the Midwest to feed cattle, pigs and poultry in Pennsylvania, Maryland and Virginia. The animals convert only about a quarter of the nutrients in the grain into meat, milk and eggs, and the remainder -- in the form of nitrogen and phosphorous in manure -- doesn't leave the watershed.

Some of the excess nitrogen and phosphorous in manure eventually finds its way to rivers such as the Susquehanna, and ultimately ends up in the bay. There, the nutrients fuel explosive blooms of algae that, when alive, prevent sunlight from reaching the bay's bottom, and when dead and decaying, absorb virtually all oxygen available in the water.

As a result, huge ecological dead zones develop in the Chesapeake each summer, making about a third of the 210-mile-long estuary, the country's largest, uninhabitable for living creatures. Nutrient pollution from agriculture is one of the contributors to a dramatic decline in the bay's celebrated oyster fishery and loss of the once-vast beds of eelgrass the Chesapeake's ecosystem depends on.

In an ideal world, Beegle pointed out, the manure would be returned to where the crops were grown, transported out of the Chesapeake watershed. "But it's hard to see how that could ever happen practically," he said. "It may sound simplistic and perhaps silly, but honestly, that is the kind of thing that needs to happen."

The imbalance is immense. A recent summary compiled by the Mid-Atlantic Water Program reports that Pennsylvania alone is more than 50 million pounds in excess of crop phosphorous needs. The problem is systemic, Beegle noted. "It results from the way agriculture is organized and goes back to the period right after World War II when people in the Midwest discovered they could grow grain using fertilizer cheaply and sell it to folks in the East for animal agriculture for a nice profit."

Farmers in Pennsylvania and the East who produce animals for food buy grain so economically that they don't need a lot of land. "You might have nutrients from a 1,000-acre grain farm in Iowa ending up on a 100-acre animal farm in Lancaster County, and this is driven by an economic advantage both producers realize," Beegle explained.

"Historically the farmer who is buying the grain and feeding his animals sees only the cost of spreading manure on his land. The environmental costs of that excess is not borne by anyone, and the whole system has evolved so that the environment is bearing that cost. The real issue now is, if it is unacceptable for the environment to bear that cost, who is going to pay?"

Farmers within the bay watershed have become much better at limiting pollution from their animals -- incorporating best-management practices into their operations, such as no-till planting to reduce soil loss and erosion, using cover crops in their rotations, observing proper application rates when spreading manure on fields, reducing runoff from barnyards, erecting stream-bank fencing and planting riparian buffers.

"Farmers have made great strides, no question, and as new technologies such as manure injection catch on, they will do even better," Beegle said. "But it's not enough. The bottom line is the nutrient imbalance continues. We have done a lot with nutrient management, and we will do even more, but we can't simply manage our way out of this situation given the large excess in the system."

Complicating the bay's excess-nutrient problem is that it is closely tied to food prices. Because the cost of dealing with the nutrient imbalance is not being paid, prices for meat and dairy products produced in the Chesapeake watershed can stay low and be competitive. But if the estuary is to be saved, the cost of environmental stewardship must be covered.

"Food consumers are benefitting from the current situation, but now somebody has to pay if we are going to solve the bay problem," he said. "Will people pay higher food prices to benefit the bay, or will they choose to buy food cheaper from other places? Should government and taxpayers pay? Or, should animal agriculture be curtailed in the bay watershed? Can this be addressed through the Farm Bill and national food policy? There are tough choices to be made."

Farmers in the Chesapeake watershed are competing in a global market, and if they have to pay the full costs of environmental stewardship, then they can't compete, Beegle contended. "The American people must realize the benefits of having a secure food supply and of having a viable agriculture in the bay watershed," he said. "The question is, how can we get these costs internalized into the global market place so that society is willing to pay the real costs of producing food in a sustainable way?

This question currently focuses on the Chesapeake Bay but ultimately affects food and environmental policy globally, according to Beegle.

"Farmers in the Chesapeake basin want to do the right thing for the bay and the environment, but we have to figure out how to give them the wherewithal to do it," he said. "All of us who live in the bay watershed and enjoy the beauty and the bounty of the watershed must have the courage to face this issue realistically."

  • Manure from livestock is applied to fields.

    IMAGE: Penn State

(Media Contacts)

Last Updated March 21, 2011