Old ways of farming, new look

Crop rotation studied for effect on productivity

June 19, 2008|By Dennis O'Brien | Dennis O'Brien,Sun reporter

BELTSVILLE - Each day this summer, Michel Cavigelli stops on his way to work to check on the grains he is growing the old-fashioned way: with crop rotation.

Cavigelli and his colleagues at the Beltsville Agricultural Research Center are looking for the most efficient and environmentally friendly ways to raise organic corn, soybeans, wheat and other grains that end up on dinner tables around the world. With concerns about agricultural runoff, the rise in food prices and projections of global food shortages, the work is considered more important than ever.

"There is a need for new information, and it's very important that the research continue," said Les Vough, a retired expert on forage crops at the University of Maryland.

Among the ideas they are looking at: crop rotation, a technique that has been around since Roman times but has fallen into disfavor with many farmers.

Since World War II, innovations have made it difficult for them to justify rotating more than two crops on a parcel.

Pesticides were introduced that wipe out the kinds of pests that thrive if soils are used for the same crop year after year. Fertilizers erased the need to rotate crops such as corn with grasses such as alfalfa, which enrich the soil with much-needed nitrogen.

But that may be changing.

Prompted in part by increasing costs for fertilizer and an increasing appetite for organic products, farmers are looking these days for natural ways to raise crops.

"More and more, people are looking for the best way to grow grain crops organically," Cavigelli said.

Cavigelli is lead scientist of the Agricultural Research Service's farming systems project, a one-of-a-kind, long-term field study that measures the environmental impacts, along with the crop yields and quality of grains grown under test conditions on a 17-acre tract in an area known as the Central Farm.

Lately, much of Cavigelli's work has focused on organic grains - an area of increasing interest to farmers and consumers. He works with an advisory committee that includes Maryland farmers and focuses on grains important to them, such as corn, soybeans and wheat.

"I've certainly picked up a few tips from him over the years," said Bill Mason, a farmer who raises both conventional and organic products on 850 acres in Queen Anne's County.

Cavigelli, a soil microbiologist, has been growing corn, soybeans and wheat on individual strips since 1999 to see which of three experimental rotation systems produce the highest yields.

This month, he published findings showing the longer the rotational cycle, the more corn produced. Rotating corn, soybeans and wheat over four or more years - and adding hay to the cycle in late summer - increased corn yields by up to 30 percent, compared with a standard two-year cycle, he said.

There were no differences in soybean or wheat yields. But the findings are expected to help organic farmers in Maryland and elsewhere make decisions about what grains they grow and when.

"It's good for people in the organic business just to know these things," Mason said.

Farms during the Roman Empire rotated crops, but what works best is far from settled: Pests and plants continue to evolve, experts say.

Farmers in the Midwest fought off a pest known as the corn root worm for years by rotating corn with soybeans. But the insect began surviving the rotation cycle in the 1990s, so that farmers are now rotating crops and using insecticides.

"Crop varieties are always changing, and the threats from nature are constantly evolving," Cavigelli said.

The number of organic farmers certified by the Maryland Department of Agriculture jumped from 70 in 2002 to 84 this year, according to Deanna Baldwin, manager of the department certification program. To be certified, farmers cannot use synthetic pesticides and are limited to nonsynthetic fertilizers such as manure, experts say.

There also are dozens of organic operations around the state that participate in other certification programs or are small enough to be exempt from federal organic certification requirements, Baldwin said.

More farmers also are showing up for field demonstrations and workshops on organic farming, Vough said.

"You have people who don't want to see any pesticides used on their food and factors like increasing costs for fertilizers and agriculture has to have options to respond to those issues," Vough said. "There's a place for organic and for conventional farming."

Mason had spent 35 years raising vegetables, but he began growing organic corn four years ago. Raising organic grains requires more time working the soil and spreading natural treatments to control weeds, he said. But organic corn and soybeans fetch about twice the price of the same grains raised conventionally. The added revenue was a matter of survival, he said.

"With all of our costs going up, it reached a point where we had to grow somehow to stay in farming full time," he said.


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