When Bay grasses began dying in the 1970s, scientists went looking for causes, and farm chemicals were high on their list.

A $26 million research effort funded by the U.S. Environmental Protection Agency quickly focused on the chemical herbicides that farmers use to kill off unwanted plants and weeds. Those herbicides, the theory went, might keep killing once they entered the Bay. But five years of research concluded that except for some farm ditches polluted with herbicides, those agricultural chemicals did not reach the Bay in strong enough doses to kill Bay grasses.

Farmers, however, were not off the hook. What was smothering the grasses, the researchers found, were blankets of sediment and algae that spread across the Bay, blocking out sunlight. With fewer grasses and more algae blooms, the Bay also began to lose something else — dissolved oxygen essential for life, especially in the summer and in the deeper waters. Much of the sediment that washed into the Bay and a good deal of the nutrients came from farm fields.

When these research results hit the press, mounting public pressure — to take away this blanket of sediment and nutrients — sparked a new level of cooperation between the Bay states and led the federal government and led to the signing of Bay Agreements in 1983 and 1987. While the first Agreement brought the states together in a general commitment to restore the Chesapeake, it was the 1987 Agreement that committed the jurisdictions to reduce nutrients by 40 percent by the year 2000. When the year 2000 came, and nutrient goals remained unmet, a new agreement, Chesapeake 2000, spelled out even more ambitious goals for improving water quality and clarity.

After two decades the clock is winding down on the court-ordered deadline of 2010, the time given the states to remove the Bay from the Clean Water Act's list of impaired waters. According to the Chesapeake Bay Program, nutrient reductions are about one third of the way toward that goal, with two-thirds of the reductions remaining to be made by the end of this decade.

The pressure to reduce nitrogen and phosphorus — as well as sediment — has intensified as success at reducing them has stalled. While new technologies can help in some cases — for example, to cut nutrient levels at waste treatment plants — it remains more difficult to control the flow of nutrients and sediment from farms, where runoff can't be put inside a pipe.

Farm boy turned Ph.D., Russ Brinsfield (left) now tracks nutrients as they seep through the soil toward the Bay. The most effective method he has found so far is the planting of cover crops (right), seen here on farm fields belonging to cousin Balvin Brinsfield. Photographs by Skip Brown.

The good news is that cover crops work. The bad news is that not enough farmers are planting them.

Think of farms as nutrient cycling machines. In their most basic and self-contained form farms use nutrients in the soil, combined with water and sunlight, to grow crops that in turn provide nutrients for people and animals. Waste from animals (in the form of manure) and even from people (in the form of sludge) can be returned to the soil to fuel the growth of more plants. In more intensive agriculture, however, farmers bring in specially prepared commercial fertilizers to boost yield. They may also raise animals — like chickens, turkeys or hogs — in very intensive operations that produce large amounts of waste in a very concentrated area. Since these operations often lack enough acres of farmland to use all that manure or poultry litter, what should be an asset becomes a liability — too much animal waste, with too much nitrogen and phosphorus, and no place to put it.

The result of bringing commercial fertilizers into the region and disposing of large amounts of animal waste on Bay area farms is a landscape that leaks nutrients from the watershed, and into the Chesapeake.

One of the scientists trying to devise ways to plug that leak grew up on a farm just across the road from Balvin and John Brinsfield. Russ B. Brinsfield (the B is for Balvin) left the family farm to get a Ph.D. in agricultural engineering, and for years he and his colleague Ken Staver have wrestled with ways to keep nutrients out of rivers like the Wye, the Choptank and the Nanticoke. How fast does nitrogen leave a farm field? What can keep it from reaching the groundwater? These are the research questions Brinsfield tackles, both as the director the University of Maryland Wye Research and Education Center and as the head of the Maryland Center for Agroecology, Inc.

To track the movement of nitrogen as it seeps into groundwater and begins its slow slide to the Bay, Brinsfield and Staver have installed wells and instruments called lysimeters on both no-till and conventionally plowed fields at the Wye's experimental farm. Using data from these devices they can watch what happens to dissolved nitrogen as it seeps through the soil after a rainstorm (see "Nitrogen's Underground Passage").

After years of research on different fields using different farming methods, Brinsfield says that the only practice that has significantly and clearly reduced nitrogen seeping through the soil is planting cover crops.

Cover crops, planted in the fall to help hold the soil and take up unused nutrients, seem to make sense to farmers like Balvin and John Brinsfield. Balvin says that even without incentives, he'd plant some kind of cover once he'd harvested peppers or potatoes, because there is no ground cover left after the harvest — no corn stalks or other residue to help hold down the soil. He says it just makes good sense.

Balvin has nearly half his land in cover crops, and John has better than half. According to the Chesapeake Bay Commission, cover crops provide one of the most cost-effective ways to keep nutrients out of the Bay (see "Where Should We Put Our Money?").

The Brinsfield cousins are aware, though, that not everyone participates in the cover crop program, for one reason or another. For one thing, they say, farmers like to buy seed in early summer, but the cover crop sign-up is in mid-summer. So they have to buy seed before they know whether they are in that year's program, which is strictly first-come, first-served. Also, to keep excess nutrients off winter fields a farmer participating in the cover crop program can't put down any manure or fertilizer before March 1. So some farmers don't enroll, they say, in case they want to fertilize sooner.

The good news, then, is that cover crops work. The bad news is that not enough farmers are planting them. Brinsfield knows we have a long way to go, because he and Staver track monitoring stations in other areas as well — like the U.S. Geological Survey's Greensboro station in the Choptank River watershed.

Brinsfield says that on the basis of data from such stations, he sees "little indication that we have significantly reduced the rate [of agricultural runoff] into Eastern Shore rivers."

At best, he says, inputs of nitrogen may be leveling off, but they're not going down. Even when conservation efforts begin to work, he says, the results may be years in coming, given the slow-motion nature of groundwater.

In fact, burgeoning federal deficits, proposed budget cuts, and hard-pressed state resources in many parts of the Bay watershed have led many to ask how we will ever reach levels of funding and participation needed to cut nutrient and sediment loads. With the nutrient problem spread among 87,000 farms across a 64,000-square-mile watershed, and with population growing in the Bay region at the rate of one million each decade, bringing increased sewage, urban runoff and the destruction of forests, one might well wonder, how will we ever restore the Chesapeake Bay?

At a recent rally in Virginia, the president of the Chesapeake Bay Foundation, William C. Baker, warned that if more progress is not made, the Chesapeake Bay Program, long touted as a national model for ecosystem restoration, may well become an international "model for failure."

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