As manure piled up in the Netherlands in recent years, farmers and the government searched for ways to get rid of the stuff before it ruined the tiny nation's water quality.
One of their solutions: Ship it here.
The Dutch government helps subsidize a program to turn chicken waste into pellets that are packaged and exported as high-grade lawn and golf course fertilizers.
"They're trying to market this stuff all over the world just to get rid of it, and hoping to make some money in the process," said David Brubaker, executive vice president of Penn Ag Industries, an agribusiness trade association. "It's starting to come into the United States. How big it's going to get, I don't really know." But he and others suggest that areas with intensive livestock industry - such as parts of the Chesapeake watershed - may soon be searching for innovative animal waste disposal solutions as well.
If they don't, some areas may find themselves facing extreme measures. The Netherlands, for example, recently mandated a 25 percent reduction in the nation's hog population to decrease manure. "We've got to address the problem now and find solutions that work," said Brubaker, who has visited the Netherlands repeatedly to learn about their nutrient management efforts. "If we don't, it will get so bad that the rules will be intolerable."
The issue has recently gained prominence in the Bay watershed because of concerns that nutrients, much of which stem from animal waste, may have helped to create water quality conditions that contributed to this year's pfiesteria outbreaks in Maryland and Virginia.
But managing manure - particularly wastes from the chicken industry on the Eastern Shore - may be particularly difficult. The problem, in a word, is phosphorus.
Phosphorus might be considered the forgotten nutrient in the Chesapeake Bay restoration effort.
In part, that's because phosphorus has seemed to be under control. Baywide water quality monitoring has shown sharp declines in phosphorus concentrations, and computer model projections show that - unlike the case for nitrogen - the Bay states will meet their 40 percent reduction goal for phosphorus by the turn of the century.
But officials say much of phosphorus improvements stem from the phosphate detergent ban implemented in the Bay states during the late 1980s, as well as upgrades at wastewater treatment plants.
On farmlands, phosphorus was considered to be largely controlled because - unlike nitrogen which dissolves in water- it binds to soil particles.
Controlling erosion, it was thought, would control phosphorus runoff. But now it appears that soils in some areas with intensive animal agriculture have become so saturated with phosphorus that it, too, is dissolving from the soils and running off the land. Water quality monitoring shows that phosphorus concentrations in many Eastern Shore rivers are increasing or, at best, just holding their own.
The reason is the content of animal waste. While the Bay states have been working to control both phosphorus and nitrogen, the two nutrients are not created equal, especially in manure.
Phosphorus is a particular problem in wastes from poultry and hogs because their stomachs - unlike the digestive systems of cows - cannot absorb phosphorus in grains. To meet nutritional needs, phosphorus supplements must be added to their diets. That means even higher levels of phosphorus accumulate in their wastes.
As a result, manure often has a higher ratio of phosphorus to nitrogen than is needed by crops. In other words, if enough manure is applied to meet the nitrogen needs of crops, far more phosphorus than is needed is also being applied.
If however, only enough manure is applied to meet the phosphorus needs of a crop, then far too little nitrogen is being placed on the land. In such a case, the farmer would suffer dramatically decreased yields or have to apply chemical nitrogen fertilizer to make up the difference. Either way, a huge amount of manure would be left over, with no place to go.
"Then, all of a sudden, you have a big waste disposal problem," said Russ Brinsfield, director of the University System of Maryland's Wye Research and Education Center.
Historically, many farmers considered manure to be valueless waste and simply disposed of it by plowing it into their fields. For the past decade or so, researchers and agricultural agencies have better quantified the fertilizer value of manure. Instead of treating manure as a waste, said Russ Mader, of the Chesapeake Bay Program Office, the objective has been "to get the agricultural community to view manure as a renewable resource instead of something to get rid of."
With the aid of nutrient management plans that evaluate the content of manure, soils and the needs of crops, fertilizer applications on fields have dropped steadily, falling 20 to 30 pounds per acre in the last decade alone.
"The trouble is," Mader said, "those plans are based on the crop needs for nitrogen, so you overapply phosphorus."
This phosphorus problem dates to the 1940s, according to Les Lanyon, a professor of soil fertility at Penn State University. At that time, research proved soluble forms of phosphorus could be mixed with grains to give animals the nutrition they needed.
That success was one factor that opened the door to large-scale animal operations for chickens and hogs - animals that previously were primarily scavengers around farms.
Making the situation worse, many areas - such as the Netherlands and the Eastern Shore - don't grow enough grain to feed the animals. Much of the grain - as well as the nutrients in them - are imported from distant areas.
Ultimately, far more phosphorus, both as grain and as nutritional additives, flows into the regions than is exported in the form of eggs or meat.
The same principles apply to nitrogen, much of which is imported from outside in the form of grain and fertilizer. Additional nitrogen from outside sources arrives through air pollution. That adds up to a huge surplus in the watershed. But some of the nitrogen will be denitrified through natural processes which convert nitrogen to a harmless gas. And much of it will also be taken up and stored in plants for long periods of time.
In the case of phosphorus, plants will absorb only limited amounts; the rest will stay in the soil. Also, phosphorus does not change forms or convert to harmless gas as does nitrogen. Instead, it remains in the soils until it is, ultimately, washed into rivers and streams and buried at the bottom of the ocean.
Ideally, Lanyon said, the phosphorus surplus from livestock operations would be needed back on the distant fields that grew the feed grain so they could grow new crops. That doesn't happen, he said, because of the availability of cheap phosphorus that is mined from deposits laid down on the ocean bottom millions of years ago and later thrust above the seas with continental land masses. Ultimately, the mining contributes to large surpluses in the environment.
"I liken it to the story in the movie, Jurassic Park, Lanyon said. "In the fiction, they went back and got the DNA and created dinosaurs that were out of place with the ecosystem that we have. We're grabbing that prehistoric phosphorus and bringing it forward in time.
This is not science fiction:
It's sharing our world, and we're not sure what is going to happen next."
Because phosphorus tends to stay around, much of the effort to "control" it actually amounts to something of a shell game in which phosphorus is moved from one place to another until it is washed into the Bay and buried in sediment.
Take wastewater treatment plants. Tighter discharge limits have reduced phosphorus levels in effluent. But the phosphorus didn't go away - it's stored in sludge.
"People who live in the city think they are doing their part by paying more money and squeezing the phosphorus out," Brinsfield said. "What they don't understand is all that sludge is applied to farm land. And with a nutrient management plan that is nitrogen-based, you are putting on several times the phosphorus that a corn crop needs. Now that phosphorus becomes part of the 40 percent reduction that agriculture has to make."
Managing for the phosphorus content in manure would mean spreading the animal wastes over more acres. By some estimates, though, there may not be enough land on the Eastern Shore to handle the 800,000 tons of chicken wastes produced there annually if it were applied based on the phosphorus needs of the land.
Compounding the problem, many farmers don't use animal fertilizer at all - chemical fertilizers are easier to apply. Much of the remaining farmland already has phosphorus levels above that needed to grow a corn crop - and may not need any for years, Brinsfield said.
"You can move it around for a while," Brinsfield said, "but somewhere down the line you're going to run out of land if you apply it based on the phosphorus requirements of the crops."
The Netherlands hit this problem years ago. It's a country that until recently had 14 million people and 15 million hogs - and millions more chickens - in an area a third the size of Pennsylvania. Two-thirds of the country is below sea level.
To manage the situation, the nation has established a "mineral accounting system" that tracks all the phosphorus and other nutrients coming into the country, as well as those that leave.
To cope with excess phosphorus, the government has subsidized a variety of strategies. Chickens and hogs are now fed phytase, an enzyme that allows their stomachs to absorb phosphorus in grains so the animals no longer have to receive special phosphorus supplements.
"Anything you can think of to try, they've already done it," Brubaker said. The Netherlands recently reduced the amount of hogs in the country by 25 percent, to 11 million. Brubaker said further reductions in animal numbers are likely.
While the Dutch example is extreme, many agricultural experts say areas within the Bay watershed that have high concentrations of animals - particularly chickens and hogs - will ultimately face the same issue.
For now, the answer may be to continue focusing on nitrogen reductions - which many say is the bigger immediate problem - while researching solutions to solve the phosphorus issue.
"It's going to take us a decade to get the 40 percent reduction in nitrogen if we start today," Brinsfield said. "That will buy us some time in figuring out how to solve the phosphorus issue."
Possible areas of research include burning the waste or turning it into a marketable product as the Dutch have done. Some have suggested that co-ops could be established that would reprocess the manure into a fertilizer with phosphorus to nitrogen ratios that could be used by plants. Whether that would be cost effective, they admit, is questionable.
Other possibilities, such as adding phytase to feed, are likely to play a role in any solution, but it may also add to the cost of production. In the end, researchers say a variety of actions will be needed to fully address the phosphorus issue. And it is probable that any solution will increase production costs. The question will become: Who pays?
"The problem that you've got is everyone wants cheap food, and there is no political will at all to assign an environmental tax to make sure that chickens are grown in a socially acceptable way," Brinsfield said.
"Personally, I think the individual who eats the chicken ought to pay a tax to make sure the chicken is produced in a socially acceptable way, but we're a long way from that."
Ultimately, he and others say that solutions will have to be regional or national in scale. If individual states go too far and pass laws that drive animal producers away, they say the problem will only be moved to states, or countries, with weaker environmental laws. It may help save the Chesapeake Bay, but it could ruin someone else's waterway.
"If they go to Mexico," Brubaker said, "they're going to create pollution down there, and there won't be any rules. So you'll not only have the economic hit that you would take in the United States, but the total mass of pollution will probably go up. That doesn't make any sense."