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If agronomists could engineer a system where every possible source of pollution was converted into a fuel or food source, farms could substantially reduce their nitrogen, phosphorus and sediment loads to the Chesapeake Bay. And if they could do that while maximizing yield, they just might be able to keep the landscape rural, the economy humming and the countryside supplied with locally grown products.
Researchers at Penn State University are trying to make that idea a reality for the state's nearly 9,000 dairy farms, most of which are small, family operations.
Armed with $400,000 from the USDA's Sustainable Agriculture Research Education Fund, a $200,000 match from the university and additional funds from the USDA's Agricultural Research Service, an interdisciplinary team of scientists from six university departments is working on the six-year project. It began this year growing crops on 15 acres of the university's research farm just outside of State College.
"We are looking at ways to minimize loss, maximize gain, and have a farm that is economically sustainable," said Penn State agro-ecologist Heather Karsten, who is coordinating the research effort.
The project emphasizes no-till and continuous ground cover with perennials like alfalfa hay and cover crops—two of the best-established conservation practices. But it goes far beyond those in its ambitions. It includes injecting manure to reduce any surface runoff, growing canola to be used as a biofuel that will run the harvest equipment, trying different forms of "green manure" - plants that add nitrogen to the soil - and applying different management techniques for reducing herbicides.
The first rotation is for forage crops and strategies to manage manure. It involves planting alfalfa, corn silage and winter wheat. This rotation tests how each crop grows when manure is oadcast versus when it is injected.
Already, the researchers have lent re-engineered manure injectors to several manure haulers. After using them three years, the haulers can keep the machines free of charge. The researchers are hoping that gift will reduce one of the big barriers to entry - cost. Farmers in the Midwest have been using manure injection for a few years, but it has yet to catch on here in part because the equipment has been expensive and wasn't designed for the Northeast's rocky soils.
Steve Lehman, a manure hauler out of Lancaster County, said the technology has improved greatly, but applying the manure with an injector is a slower process. He can cover 14 feet at a time with the injector, as opposed to 40 feet with the traditional oadcast spreader. And, he said, getting the equipment for free after three years is not exactly a deal, as he spends a lot of his work time demonstrating the technology.
But Lehman said the project has promise, both ecologically, and economically.
"We've been working with manure for 20 years. No-till and manure, surface-applied, I'm not convinced that's a real good match. You allow your nitrogen to volatilize, and it's more susceptible to runoff," Lehman said. The injector technology is still relatively new, he said, "but I'd say, so far, so good."
Unlike poultry farms, which often produce excess manure because they don't have the land mass to spread it on, dairy farms usually don't have enough manure. That's because they grow grains on their farm to feed their cows, and they use all the manure they have to fertilize those crop acres. Chicken farmers, in contrast, often have to import their feed, in addition to exporting their manure. Dairy manure is water-based and therefore more expensive and less efficient than chicken manure to move around, but there's less of a need to move it because dairy farmers can use what they produce.
Manure injection could save dairy farmers money because they would not lose fertilizer to runoff or volatilization, and there' would be less of a need to supplement with commercial fertilizer. And it would smell better. If it doesn't volatilize, it won't give off an odor, which is sure to make relations with the neighbors easier.
The second rotation in the Penn State experiment is for how to reduce herbicide use on grain crops, including soybeans and corn. It tests the efficacy of spraying standard herbicide versus alternative methods, such as adding crops that suppress weeds or banding the herbicide over the crops and cultivating between the rows with a high-residue cultivator. The idea is to reduce the amount of herbicides that can contaminate the water, and lessen the risk that certain weeds could become resistant to the poisons. The diverse crop rotation can also provide habitat for beneficial insects that help control weeds and the pesky slugs that feed on crops.
In both rotations, the researchers are growing canola. They will press the seeds and use the oil to fuel the tractor, which has been outfitted to use vegetable oil. The meal, then, will be fed back to the dairy herd. Winter canola may be another option for farmers looking to keep a crop on the soil year-round, Kartsen says.
The forage rotation is testing green manure: plants that grab nitrogen from the atmosphere, rather than the soil, and "fix" it, so it can fuel their growth. When the plants are plowed under, the nitrogen they fixed becomes available for the next crop to use. The experiment is comparing two kinds of green manures: red clover and hairy vetch.
Joel Myers, Pennsylvania's former agronomist and a longtime farmer, said he's glad red clover is making a comeback: It's inexpensive, an excellent source of fiber for growing calves, and will also reduce the need for herbicides.
Myers, an adviser on the project, is also hoping the research shows other options for feeding cows besides corn silage, which requires lots of nitrogen. He thinks that the research could prove what agronomists and ecologists have been saying for years - managing runoff is both good for the environment and good for business.
"I think we're going to document some things that we already know, but we really don't have documentation," he said. "The concept of having something growing all the time is appealing. We're just starting to get that message out."
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