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It's MORNING EDITION, from NPR News. I'm Steve Inskeep.
RENEE MONTAGNE, HOST:
And I'm Renee Montagne. We're now going to spend a few minutes talking about where our food comes from and what nourishes those plants that, in turn, feed us. Every farmer uses fertilizer. Many organic farmers keep their fields fertile with manure from animals.
It's good for the environment, but the federal government now says there's a risk that it could make consumers sick. New rules would restrict the use of manure but organic farmers are fighting back, as NPR's Dan Charles reports.
DAN CHARLES, BYLINE: It's a crisp, fall morning in south-central Pennsylvania, and Jim Crawford is doing something he loves...
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CHARLES: ...feeding his fields at New Morning Farm.
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CHARLES: His field manager, Pearl Wetherall, is pulling a manure spreader across a field where cabbage grew last summer. For Crawford, this animal waste is not waste. It's black gold.
JIM CRAWFORD: It's the best thing in the world for creating fertility in a natural, biological way.
CHARLES: Crawford buys hundreds of tons of manure every year from a big turkey farm a few miles away.
CRAWFORD: It's just really at the heart of our whole operation for having good, rich soil and good fertility, so we have the highest-quality crops.
CHARLES: It's also part of a natural cycle, the basis of organic farming. Growing crops strips nutrients from the soil. But the nutrients don't disappear. If you feed those crops to cattle or turkeys, the nutrients mostly end up in manure. Crawford says the right thing to do is bring them back to the soil.
CRAWFORD: Cycling nutrients is what it's about, cycling organic nutrients.
CHARLES: This is typical among organic farmers, especially the smaller ones. But now they may have to change, because the Food and Drug Administration considers manure a food safety risk. You can sometimes find nasty, disease-causing microbes in manure - salmonella, for instance.
Patricia Millner, a microbiologist with the U.S. Department of Agriculture in Beltsville, Maryland, says scientists are trying to figure out exactly how long such bacteria survive in the soil.
PATRICIA MILLNER: In some cases, salmonella will survive for a few weeks. And in other cases, it'll be reported that it survives 300-and-some days.
CHARLES: And when they survive, they do get on food. Carrots or radishes, of course, grow right in the soil. But bacteria also get on salad greens.
MILLNER: Rainfall, there's splash that splashes them onto the plants.
CHARLES: There's a lot of uncertainty about exactly how big of a risk this is. But the FDA is saying better safe than sorry. It's proposing new national food safety rules. And if those rules go into effect, when farmers spread raw manure on a field, for the next nine months, they won't be allowed to harvest any crops from that field that people eat raw, like carrots or lettuce.
The rules don't apply to really small farms. They apply to farms with more than half-a-million dollars in annual sales, or which supply food to supermarkets. But that includes Jim Crawford's farm. He says he already follows the organic rules. He doesn't harvest crops within four months of spreading manure. But having to wait nine months - longer than a growing season - would completely disrupt his operations.
CRAWFORD: We wouldn't even be able to function.
CHARLES: There is an alternative: Composted manure. The heat from composting kills disease-causing microbes. But compost is three to six times more expensive than manure, and Crawford doesn't see why he should switch. He just doesn't believe that what he does now is at all dangerous.
CRAWFORD: No one's ever been sickened by anything we've grown, and in probably, literally, millions of transactions between our customers and us over 40 years.
CHARLES: The organic produce industry is not united on this. There's a divide between big and small. Will Daniels is the chief food integrity officer for Earthbound Farm in California, which sells organic salad greens nationwide.
WILL DANIELS: History is not always your greatest ally, unfortunately. We never thought that, you know, we would see spinach or other produce involved in outbreaks.
CHARLES: But in 2006, Earthbound Farm's spinach was linked to an outbreak of disease. Two hundred people got sick. Three died.
Now, raw manure was not the source of that outbreak. But Will Daniels says it's a risk his company will not take.
DANIELS: Primarily, we use a pelletized, processed chicken manure product.
CHARLES: All the bacteria in that fertilizer have been killed with heat and pressure.
DANIELS: We've gone that direction because we feel that it's very important to assure that we are not spreading these pathogens out in our field that could lead to contaminated product.
CHARLES: Daniels supports the FDA's proposed rules on manure. Many smaller organic farmers, meanwhile, are sending the FDA a blizzard of comments, arguing that the environmental benefits of using it outweigh the risks. The comment period ends this week.
Dan Charles, NPR News.