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Roots of Soil Knowledge

01:53AM Feb 09, 2013

A lifetime of research helps farmers feed the soil

With his trademark white beard, fedora hat, and easy- going manner, professor Ray Weil looks the part of a distinguished county agent from years gone by. Ag school students might recognize his name on their soils class textbook, "The Nature and Properties of Soils", which has been the standard text for decades.

As a soil ecologist with a long list of university accolades, Weil teaches and conducts soils and farming systems research at the University of Maryland in College Park.

With a lifetime of research dedicated toward managing soil organic matter, nutrient cycling and cover cropping, he finds himself at the center of a growing interest in cover crops and the resulting farming systems that boost yields with less effort and inputs.

"I’m optimistic," he says. "It may be only 1% to 2% of the total farmers out there [growing cover crops], but they’re showing it can be done and profitably. I think the whole idea of soil health and treating soil as an ecosystem is accepted now and with this interest by the leading farmers, it’s
really going to take off."

Adoption of new ideas takes hold over time if there are compelling reasons to initiate change—such as the shift toward cover crop systems and maintenance of soil organic matter. "The emphasis in soil education has changed tremendously," Weil says. "When I was an undergraduate at Michigan State University in the ’60s, there was little emphasis on organic matter and soil biology."

He says he was fortunate to be able to immediately emphasize these principles when he started teaching.

He ascribes to the belief that farmers feed the soil—not the plants they’re growing. "The fertilizer you put on feeds the [soil] system. We used to recommend 1.5 lb. of nitrogen (N) per bushel.

We’re down to 0.8 lb. or 0.9 lb. and we haven’t suffered any yield loss. Most farmers who put down 150 lb. of N think it’s going into the corn; but when you use N that’s tagged with a tracer (like N15), you can follow the isotope to see where it goes," he says.

He says you never find more than half of it in the corn at the end of the year. "Usually, it’s about a third. That leaves the remainder in the soil ecosystem, the Gulf of Mexico or in the atmosphere," he explains.

Like most farmers, Weil is point-blank practical. He explains that farmers are unique ecosystem managers. "He’s stuck with what he can grow by what he can sell, and, in the Midwest, it’s a short list of corn, soybeans and wheat," Weil explains. "We know that it’s diversity that makes ecosystems resilient and productive to avoid things like diseases."

The missed opportunity today is that farmers are only using their soil for three to four months, but they’re paying for 12 months.

"The soil is working and nutrients are moving around for those 12 months. Cover crops enable you to go in and use it for the other nine months, to keep the biology going to capture those nutrients, to capture that sunlight and turn it into organic matter that’s going to make your system more productive," he says.

Weil sees a brighter future for farmers with the emphasis on soil organic matter and building it with the use of cover crops­—once they get past the early adopter stage to critical mass usage. "I think it’s going to change the face of agriculture," he says.