Some simple facts about agriculture in the Bay region:
- Farming accounts for about 13 percent of all economic activity in the watershed.
- It’s the second largest land use in the watershed after forests, covering about about 9.5 million acres, or nearly a quarter of the Bay’s drainage.
- It’s the largest single source of nutrients to the Chesapeake, accounting for roughly two-fifths of all the nitrogen and phosphorus entering the estuary each year, according to Bay Program estimates.
- The Bay Program will never reach its cleanup goals unless new ways are found to keep those fertilizers on the land growing crops, and out of the Chesapeake, where they grow algae.
The region’s biggest challenge in the coming years may be trying to change the last two facts without significantly altering the others.
The challenge is huge: To meet new water quality goals for the Chesapeake, the Bay Program estimates that the amount of nutrients reaching the Bay must be slashed roughly 50 percent from their mid-1980s levels. Put another way, the Bay region must accomplish twice as much as what it has done in the past 15 years.
“Those goals are so challenging that we clearly need to see where we can get more reductions without running agriculture out of business,” said Tom Simpson, chair of the Bay Program’s Nutrient Subcommittee and a soil scientist with the University of Maryland’s College of Agriculture and Natural Resources. “I don’t think we can get there just using the set of tools that we have today.”
Simpson was part of a two-day workshop in May that brought together about 50 scientists, state and federal officials, and others to assess the success of efforts undertaken during the past decade, and to examine what can be done better—and what technologies hold promise—in coming years.
The message from the workshop, which was sponsored by the Bay Program’s Scientific and Technical Advisory Committee, was both sobering and hopeful.
The sobering message was that past efforts to control agricultural runoff have probably been less successful than believed. The hopeful news was that the better application of existing practices, and new technologies on the horizon, hold great potential.
The Bay’s nutrient problem stems in large part from new technologies in the past half century that enabled chemical fertilizers to be cheaply manufactured and transported, allowing it to replace difficult-to-handle animal manure as the main source of nutrients on the region’s croplands.
Further, even as the need for animal manure was replaced, the number of animals in the watershed grew. Feeding those animals has increased the amount of grain imported into the watershed—also a source of nutrients. The result has been a excess of nutrients, largely from animal manure, which inevitably run off the land.
That, combined with growing amounts of nutrients from air pollution and wastewater treatment plants, resulted in huge “crops” of algae forming in the Chesapeake: In some places, algae concentrations are more than 10 times greater than what they were a half-century ago. The algae blot sunlight needed by important underwater plants and, when they decay, deplete the water of oxygen.
Farms have been the target of major nutrient control efforts in the watershed for more than a decade. According to Bay Program estimates, farm runoff has been slashed by roughly 20 percent. Unfortunately, most workshop participants agreed, much of those reductions exist only on paper.
Bay Program figures show that more than 2.2 million of the roughly 5.5 million acres of cropland in the watershed have nutrient management plans.
Nutrient management plans are site-specific guides aimed at optimizing the application of fertilizer on fields based on soil tests, crops’ needs and other factors. The goal is to minimize the application of excess fertilizer so there is less available to run off the land or sink into the groundwater.
Plans may also call for other efforts to control nutrient runoff, such as the establishment of grass buffers or other practices aimed at either soaking up leftover nutrients or containing them on-site in ponds or waste storage lagoons.
Those plans are the largest single source of agricultural nutrient reductions, according to Bay Program figures. The problem is, most agree that the plans are often not fully implemented.
The result is that Bay Program estimates sometimes do not reflect reality. In some watersheds, such as Maryland’s Eastern Shore and Virginia’s portion of the Potomac watershed, the Bay Program’s computer model indicates that nitrogen loadings from agriculture have decreased by a third. But actual water monitoring data shows nitrogen loads are either steady or trending upward.
“The model assumes that if a plan is written, it is being implemented,” Simpson said. “Assuming that everything that is written is implemented is something that the Bay Program needs to address.”
For instance, although Pennsylvania has nutrient management plans written for 300,000 acres, it has little information about the degree to which those plans have been implemented, said Doug Beegle, a professor of agronomy at Penn State University.
He cited a study in one Pennsylvania watershed that showed that only 22 percent of farms had implemented more than 70 percent of their nutrient management plan, while 57 percent had implemented more than 30 percent of their plan. And those implementation levels, he said, were reached with “intensive” one-on-one assistance to the farmer—something that normally does not happen.
“The plan isn’t a practice. The plan has to be implemented to have an effect,” Beegle said. “Too often, I think these plans are written and that is the end of it.”
Even when implemented, it’s questionable whether some of the structural controls, such as terraces, ponds, waste storage lagoons and streambank stabilization projects, are achieving predicted results.
Theo Dillaha, a Virginia Tech professor of biological systems engineering, said most studies of such structural practices have been short term and focused on areas with no previous controls of any sort. Also, there is little information about how quickly structures lose their effectiveness. A grass buffer’s ability to trap phosphorus and sediment can drop dramatically over time.
Further, the effectiveness of practices can be site-specific. “Something can be 90 percent effective in one location, but only 5 percent effective in another location,” Dillaha said.
He credited Bay Program officials with putting “some real thought” into trying to credit realistic nutrient reductions to such practices, but said the estimates still did not take into account their likely decline in effectiveness over time.
Also, the Bay Program’s models assume that practices perform equally well in all weather conditions, although studies show heavy storms can overwhelm nutrient control efforts.
Simpson said the overestimates occurred because the Bay Program led the nation in trying to predict the effectiveness of runoff control practices and had to make estimates based on limited research. “We don’t have to be apologetic,” he said. “The problem with being on the cutting edge is that you often get pretty bloody.” Overestimates are not limited to agriculture he added: Estimates of the effectiveness of urban runoff controls may be overly optimistic as well.
The key, he said, is refining the estimates so officials can better determine what has been done—and what must still be accomplished—to meet new cleanup goals. Efforts are under way to update the model and incorporate more realistic assumptions about the effectiveness of various nutrient control efforts over time, as well as their ability to withstand storms.
Meanwhile, some new technologies hold the potential for huge nutrient reductions. University of Maryland researcher Rosalina Angel presented figures showing that adding the enzyme phytase—an additive that helps certain animals better absorb phosphorus—to feed in Maryland had resulted in a 14 percent reduction in the amount of phosphorus excreted by broiler chickens.
Better implementation, she said, could boost that figure to 30 percent and—in combination with other feed additives—a 40 percent reduction in phosphorus from broiler chickens could be realized. Eventually, new techniques may push the reduction as high as 90 percent, she said.
But, she added, more research is needed about how to optimize chicken feed to ensure it does not increase the risk of broken bones in the birds, which could result in bone chips in the meat, a major concern of the poultry industry.
Angel also said that research for other kinds of chickens, and for turkeys, lagged behind that of broiler chickens. Used incorrectly, she said, phytase could actually result in increased soluble phosphorus in wastes, which more easily runs off the land. “It is important that as we move forward, we implement phytase correctly,” she said.
Likewise, optimizing the diets of dairy and beef cattle can reduce their nutrient output, said Richard Kohn, associate professor in the University of Maryland’s Department of Animal and Avian Sciences.
Kohn said about 70 percent of farmers feed animals more than is needed, resulting in an additional 10–15 percent of nitrogen inputs beyond their nutritional requirement. That means more grain has to be grown as feed, and more nitrogen is produced in waste. Watershedwide, he said, cattle get nearly $18 million more food than they need.
Optimizing diets could lead to nutrient reductions, he said, but most farmers do not formulate the feed for their animals. “It’s not the dairy farmers making the decisions,” he said. “It is the feed companies making the decisions.”
Kohn said incentives need to be found to get feed providers—who are not the target of current nutrient control programs—to better optimize the nitrogen and phosphorus components of animal feed.
Other progress can be made in the better implementation of practices that have been shown to be effective, such as planting fall cover crops, which soak up excess nutrients left on fields. John Meisinger, a scientist with the U.S. Department of Agriculture’s Beltsville Agricultural Research Center, said studies showed that fall cover crops may reduce nitrogen seeping into the groundwater by as much as 50 percent in some cases.
Better use of existing soil testing technology can better guide nutrient applications. “If we could just do what we already know works, we would be so much better,” said Tom Sims, a professor of soil and environmental chemistry at the University of Delaware College of Agricultural and Natural Resources.
The biggest hurdles, he said, are confined to parts of the watershed with heavy animal concentrations where excesses of animal manure are accumulating because there is more than is needed on the land. The accumulation is so severe, Sims said, that soil tests show that in some parts of the Eastern Shore, 90 percent of the soils need no additional phosphorus—and therefore no additional manure—to grow crops.
Manure is generally too expensive to ship very far for use as fertilizer on farms. But some innovative efforts are under way, such as a project supported by chicken processors to pelletize for export between 80,000 and 120,000 tons of Delaware’s chicken waste a year. Others hope to build manure-fired power plants.
“I think we’re making some progress,” Sims said, but he added that more needs to be done to help areas with “severe” waste accumulations to achieve a nutrient balance.
One of the problems with resolving that nutrient balance, several scientists said, is that the nutrient management plans that farmers may develop for their operation are often in direct competition with the overall goals of the farm operation.
The farmer often wants to increase animal production to increase profitability—an objective that makes it difficult to develop an effective nutrient management plan if he has too little land on which to apply the waste.
In those circumstances, said Les Lanyon, a Penn State professor of soil science and management, a farm-specific plan is unlikely to achieve a nutrient balance on that farm. The economic incentives to farmers to maximize production outweigh those to protect water quality. What’s true on an individual farm is also true for larger regions that import more nutrients—in the form of feed—than they export in terms of products: chickens, beef or milk.
“We have to prioritize clean water as we prioritize milk production and commit the resources to that product,” Lanyon said. That may not happen, he said, unless a “grand strategy” is developed, perhaps at the federal level, that addresses broad-scale nutrient imbalances not only in the Bay watershed, but in other areas of the nation.
But efforts to do that were dealt a blow, some said, by the EPA’s recently adopted rules for large livestock operations, known as CAFOs, or Confined Animal Feeding Operations. The Bay states have been moving toward adopting programs more restrictive than those likely to be required by other states under the new federal rules, which could put the region at a financial disadvantage.
“Everywhere, they are subject to weaker regulations, said Jim Pease, an extension specialist at Virginia Tech. “They are not on an even playing field with us.”
But the 2002 Farm Bill, which has several components that promote innovation to improve water quality, offers some promise. In the future, Simpson said, programs may emerge that will pay farmers to apply less fertilizer on crops.
Farm Bill programs that promote crops such as warm season grasses, which sequester the greenhouse gas carbon dioxide from the atmosphere, may provide farmers with alternatives to more traditional crops such as corn, wheat and soybeans, which are associated with high levels of nutrient runoff. “This is all a long ways away, but it is food for thought for moving beyond where we are today,” Simpson said.
Technologies on the horizon show great promise. New high-tech equipment is being developed that can simultaneously examine the soil and automatically adjust the application rate of fertilizer.
Some advocated a long-term move away from the Farm Program method of rewarding farmers who implement specific conservation practices. The best way to get nutrient reductions, Pease said, may be to set water-quality-based performance standards, and let farmers figure out the best ways to achieve them. Farm Bill money would be used to reward farmers who meet the objectives, he said.
“They could find ways to do it we never imagined, sometimes at better performance and less cost,” Pease said.
Both short– and long-term prospects for nutrient reductions will be evaluated by a panel created from the workshop, which is expected to complete a report by this fall.
Its recommendations may guide efforts in the watershed for the next decade, and former Maryland Department of Natural Resources Secretary Chuck Fox, who actively sought some of the new programs in the Farm Bill, challenged the group to make bold recommendations.
“The Bay will not be saved unless we do more on the agricultural side,” said Fox, who is now vice president for external affairs with the Chesapeake Bay Foundation.“ If you are not bold on this question, no one else is going to be bold, and we will be sitting around 20 years from now having the exact same conference.”