Smart Farming for a Cleaner Bay

By Merrill Leffler

With cover crops and no-till farming, the Chesapeake Bay Program could meet its goal of reducing nitrogen 40 percent by the year 2000," says Russ Brinsfield.

A bold assertion from the director of the University System of Maryland's Wye Research and Education Center but one that is based on nearly a decade of research on test plots and demonstration farms.

While nutrient runoff from suburban development of once-rural areas is on the rise and presents an increasing challenge, farming still accounts for the largest use of land in Maryland. Farm acreage in the state dropped nearly 40 percent between 1965 and 1996 - nevertheless, more than two million acres, over 3,000 square miles, are still in agriculture.

Because the application of fertilizers and manure in regions of intensive farming threaten nitrate contamination in groundwater and phosphorus build-up in soils, researchers at the Wye have been trying to determine the most effective practices for keeping fertilizers on farms and out of surface and groundwater.

Though nitrogen and phosphorus are key to the Bay's rich productivity - they stimulate algal growth at the base of a bountiful estuarine food chain - their massive runoff from the land has also been key to the Bay's decline.

Researchers have been trying to determine the most effective practices for keeping fertilizers on farms and out of surface and groundwater

In a pattern that has become common to many coastal waters, nutrient overloading leads to algal growth far greater than a more balanced food web can assimilate. In early spring and summer, blooms of algae will blanket surface waters, choking off light below. As unconsumed algae decompose and rain down onto sediments below, they deplete oxygen in bottom waters - the observable effects can become evident in the loss of underwater vegetation, in fish kills and in the death of bottom-dwelling organisms such as oysters and mussels.

While some farms drain directly into the Bay's main stem, many more border the river and stream systems that eventually empty into the Bay.

To reach the Bay Program's 40 percent reduction goal and maintain it at those levels in the years ahead means stemming nutrient runoff from these systems - for example, from the Potomac and Patuxent watersheds on the western shore, and the Choptank and Nanticoke watersheds on the Eastern Shore. Stemming nutrient flow into the rivers depends on curbing runoff to hundreds of feeder creeks and streams.

It is for these reasons that in 1992, the Chesapeake Bay Program moved its efforts upstream - upstream is where the farms are, where population is increasing, where land is being cleared, where housing and business development is occurring, where more septic systems are being installed. Upstream is where the Tributary Strategy and Citizen Implementation Teams for meeting the Chesapeake Bay restoration were born. It is where we have to meet the challenge that both changing and traditional land uses have on the future of the Chesapeake.

Nutrients and Tributaries

The Tributary Strategy consists of specific plans for major Bay tributaries to achieve the 40 percent nutrient reduction - these plans include point by point recommendations for meeting the goal. Teams of 25 to 30 members appointed by the governor for each tributary - and representing business, agriculture, academia, environmental concerns, and government - are asked to ensure that the Strategy works equitably.

Lauren Wenzel, Manager of the state's Tributary Strategies Program, says, "The idea behind the Tributary Strategy was not a blue print but a goal or plan, a starting point. One of the most helpful things," she says, "is for the teams to look at goals and to ask if they are realistic. Are they on track? What are the resources?" We are depending on these teams, she says. "If we were doing everything, we wouldn't need them."

The concept, says Mauro Chiaverini, Jr., chair of the Lower Potomac Tributary Team, is brand new. "It hasn't been tried before anywhere in the country. We're making it up as we go." Chiaverini, an officer in a land development company, says "these teams have brought together a lot of people who don't ordinarily get together in a civil environment. Usually it's an 'us and them mentality,' with both sides at odds."

"Our focus on nutrient management is the biggest change
in agriculture in Maryland."

Maryland identified ten tributary watersheds - for each a set of nitrogen and phosphorus reduction caps were calculated so that when summed they would add up to the statewide 40 percent reduction goal. This means a decrease from 27 million pounds of phosphorus and 353 million pounds of nitrogen in 1985 to 17.7 million pounds of phosphorus and 276 million pounds of nitrogen by 2000. The Patuxent watershed, for example, has an annual cap of 330,000 pounds of phosphorus and 3.5 million pounds of nitrogen, while the Choptank watershed has a phosphorus cap of 200,000 pounds and a nitrogen cap of 2.8 million pounds.

In certain watersheds on the western shore, curbing nutrient flow from farms will contribute significantly to staying below their cap. On the Eastern Shore farming will be a major nutrient contributor: in all three watersheds - the upper Eastern Shore, the Choptank River and the lower Eastern Shore - nonpoint loading of nitrogen and phosphorus far outweigh point source discharges. This is because the region is so heavily dominated by row crop agriculture and poultry farms. While improvements in waste treatment plants to remove phosphorus and nitrogen from direct discharges to the Choptank will reduce loading, the benefits of such reductions pale in comparison with those that will result from keeping fertilizer and animal waste on the land.

For such reasons, says Russ Brinsfield, research at the Wye Research and Education Center has concentrated on improving farming practices that could simultaneously maintain crop yields while minimizing impacts on the Bay. These efforts have engaged University scientists, the Maryland Department of Agriculture and farmers themselves.

Keeping Nutrients on the Farm

"The state and University have made enormous progress," says Brinsfield, "in working with farmers."Richard Hutchison, an Eastern Shore farmer, says that "many farmers have been applying nutrients in a more timely manner - when plants are going to use them, and in some cases," he adds, "they are applying less."

According to the Chesapeake Bay Program, average nitrogen and phosphorus applications in Maryland, Pennsylvania and Virginia have dropped by 20 to 30 pounds per acre per year during the past decade. Soil specialists no longer recommend 120 to 130 pounds an acre to get an expected yield of 100 bushels of corn. Today, nitrogen recommendations average about 100 pounds an acre.

Assessing fertilizer applications and tailoring them for each farm and type of soil is part of Nutrient Management Planning, a program that aims at minimizing nutrient pollution. First begun in 1989 with assistance from the University's Cooperative Extension Service, the program accelerated in 1992 when the Maryland Department of Agriculture began an accreditation program for training private consultants who can then provide recommendations on managing crop nutrients such as commercial fertilizers, animal manure and other organic sources such as waste treatment sludge.

"Our focus on nutrient management is the biggest change in agriculture in Maryland," says Lewis Riley, Secretary of the Maryland Department of Agriculture. "Although managing nutrients has always been part of farming, we now are more closely monitoring factors such as yield results and soil fertility to increase efficiencies."

Maryland's is the first such volunteer program in the country. To date, more than 800,000 acres of state farmland is under nutrient management. The goal by the year 2000 is about 1.3 million acres.

"These plans also show farmers ways to save money," says Brinsfield. And saving money speaks loudly. "It's an economic factor," says Rich Hutchison. "It costs money to put fertilizer on, so if you can get the same crop yield for less cost, it makes sense."

Despite the number of acres now under nutrient management, these effects have yet to show up in the form of nutrient reduction in the river. "They haven't translated themselves through the flow system," says Brinsfield. That delay results from the tremendous lag time, he says, between introducing fertilizers, or curbing them, and their slow movement beneath the root zone and, for nitrogen, into groundwater. "It could be five to ten years before we see measurable changes," he says.

Major practices that are especially important in keeping nutrients on the land are no-till farming and cover crops, says Brinsfield - without them and other Best Management Practices, he says, we cannot reach the 40 percent goal.

With no-till, sediment losses are significantly lower, though the practice often leads to elevated levels of dissolved phosphorus. Brinsfield recognizes the problem. "We need to find a way to preserve the value of no-till but deal with those higher [phosphorus] levels," he says. One hope is to make sustainable reductions in phosphorus by reducing fertilizer application rates to levels less than the crop removal rates.

Though no-till and other practices such as terracing sloped landscapes - more applicable to western shore topography than the flat Eastern Shore landscape - reduce soil erosion and runoff of phosphorus, these practices often fail to curb nitrogen, since nitrates dissolve and move with flowing water, even when sediments are stopped.

Even with reducing the amount of nitrogen fertilizer (and applying fertilizers at the best times), the most farmers can get from corn uptake is about 65 percent of the nitrate. This leaves considerable excess nitrogen in the soil.

And it is here that cover crops offer the greatest promise.

The Case for Cover Crops

Cover crops are small grains such as rye or barley or winter wheat that are planted without fertilizers, immediately after harvesting corn or other row crops. If planted early enough, cover crops can use nitrates in the root zone before they seep through into groundwater or creeks and rivers.

Ken Staver and Brinsfield have found that when a grain like winter wheat is planted soon after corn or soybean harvests, it can take up a good deal of that residual nitrogen and prevent it from reaching groundwater.

In test plots planted with soybeans at the Wye farm between October 1994 and April 1995, Staver and Brinsfield calculated a five-fold reduction in nitrate, from 36 pounds an acre to 7 pounds an acre.

Both farmer and researcher, Russ Brinsfield has been tracking nutrients and testing cover crops to keep fertilizers out of the Bay.

So why aren't farmers flocking to cover crops? Economics. "In the short term," says Brinsfield, "cover crops cost the farmer extra dollars."

For several years, the state provided farmers with a $30-an-acre subsidy to plant cover crops. The result: farmers seeded some 25,000 acres statewide with winter grains. However, when the state eliminated the cost share program, many farmers stopped planting them. Very few participate voluntarily. According to Betsey Krempasky, chairman of the Choptank Tributary Strategy Team, only 2,718 acres were planted in that watershed in 1996.

And yet, says Brinsfield, planting cover crops is one of the most effective means for removing the greatest amount of nitrogen per dollar. Should the government provide a subsidy if it can help reach the 40 percent nutrient goal? Some point out that poultry and cattle farmers are eligible for cost share programs to build structures to contain animal waste, and the Choptank Strategy team believes that cover crops should also qualify - and has written the governor requesting his support.

Brinsfield also believes that the state should pass special legislation to provide cost share. "We could exceed the 40 percent reduction goal [on agricultural lands] with them and with other Best Management Practices," he says. But he has a caveat as well. While we need state support, we also need an initiative that would phase out cost-share. "We need to expand our research to figure how we can reduce costs and how these programs can pay for themselves,"he says.

A starting point may be aerial seeding. In the upper Eastern Shore, the Tributary Strategy Team has received a grant that will look at the effectiveness of planting seed from an airplane: they are contracting with farmers for seeding 1,000 acres throughout the basin. If successful, it could help in reducing planting costs, which could help overcome resistance to voluntary adoption or perhaps reduce potential cost-share.

Another possibility is pollution trading - instead of employing advanced waste treatment in areas where its effects are minimal, that money could go toward funding cover crops if their potential benefit in reducing nutrient pollution were greater.

One thing is certain - curtailing nutrient runoff from farmland is a key to restoring and protecting the Chesapeake. Whatever works to keep excess nitrogen and phosphorus out of the Bay will likely prove the best action to take.

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