No-till philosophy expanding in Virginia

Virginia crop advisors have counseled farmers for years on the advantages of long-term no-till. Well regarded Soil Scientists like Mark Alley at Virginia Tech University and Extension Coordinator Paul Davis have likewise preached the benefits of never-till for years.

In recent years, no-till farmers like Jon Black, David Hula and John Hula, who farm along the James River in Charles City County, Va., have won major awards for yields on no-till land. Black, Hula, Davis and a handful of other Virginia growers have been no-tilling for a number of years.

Virginia Crop Advisors Paul Bodenstein and David Moore are among a growing cadre of professional crop consultants who are expanding the no-till philosophy to other parts of Virginia.

Bodenstein, who is a certified professional agronomist with Ag Systems in Mechanicsville, Va., worked with Virginia Wheat Yield Winner Chuck McGhee. The 2008 high yield of 131 bushels per acre more than doubled the 2007 state yield average of 64 bushels per acre.

McGhee and third place winner Ronnie Russell of Corbin Hall Farm in Water View, Va., are both long-time no-till farmers. No-till wheat farmers contributed significantly to a record 2008 average yield of 71 bushels per acre in Virginia.

Moore works with a number of farmers along the shores of the environmentally sensitive Chesapeake Bay, including Ronnie Russell who placed third in the 2008 statewide Wheat Yield Contest with 111 bushels per acre.

Moore says farmers in his area had to look for more conservation friendly practices to avoid the ire of environmentalists charged with safeguarding Chesapeake Bay. Farmers are quickly learning that being more environmentally friendly doesn't run counterclockwise to growing high yielding crops.

The Virginia Tech expert says non-agricultural environmental groups are beginning to take notice of the advantages of no-till farming.

Ann Jennings, executive director of the Virginia Chapter of the prestigious Chesapeake Foundations, recently praised Virginia wheat farmers for their leadership in using conservation practices that produce valuable crops and also help the state in meeting its goal of improving water quality.

Continuous no-till leaves the surface of the soil undisturbed, reducing soil erosion by as much as 90 percent. Soil erosion and runoff cloud water, bury underwater plants and animals in silt, and can carry nitrogen, phosphorus, and other agricultural chemicals that harm aquatic ecosystems. Excess nitrogen and phosphorus contribute to noxious algal blooms and dead zones, according to a recent report written by Matt Nilsson in the American Society of Agronomy Journal.

It's hard to find a grain grower these days who doesn't no-till, but it wasn't always that way. Moore says making the switch from conventional to no-till took getting used to for Virginia grain farmers in his area.

“When we first started using no-till we had things planted too deep the first year and probably not deep enough the next year. It took a while to realize we can plant at about an inch to an inch and a half consistently with no-till,” Moore says.

Long-time no-till soil has both better water holding and better water drainage qualities than conventionally-tilled soil, often giving the grower a bigger window of opportunity to use the improved seed bed.

Bodenstein says a big advantage of no-till is that it produces a firm seedbed, which is critical for getting an even stand.

“Our data shows that if you get wheat emerging more than seven days after the first wheat emerges, you go from 105-bushel wheat down to 35-bushel wheat. Even emergence is so critical with wheat,” he stresses.

The recent dramatic spikes in fertilizer prices have forced growers to take a harder look at production systems that utilize less fertilizer without creating yield drag. Nitrogen in some areas in the summer of 2008 quadrupled in price then dropped back to within 25 percent of the original price — all in one growing season.

Such dramatic, and sporadic changes in input costs make no-till or strip-till a good option for virtually any crop grown in the upper Southeast.

“We used to use about 2 pounds of nitrogen per bushel, and we're down now to right around 1.2 pounds of nitrogen per bushel. So by no-tilling, we're building up the organic matter, and it's releasing nitrogen. We're not as efficient as we think we can be, but we're getting pretty darn efficient,” Bodenstein contends.

Paul Davis and Mark Alley are taking the nitrogen savings a step farther by looking at cover crops that protect the soil and have the capability of making nitrogen.

In one 40 acre field Davis looked at rye, vetch and a combination of rye and vetch as cover crops for a rotation of pumpkins, soybeans and corn. At the end of the study he hopes to know more precisely how much nitrogen is available to small grains from the vetch cover crop.

In the interim, results are positive, he says. “Last year in pumpkin fields where we planted vetch we used only the standard 65-70 pounds of nitrogen and had a great crop. In fields with rye only as a cover crop, we had to come back with an additional 40-50 pounds of nitrogen per acre,” he explains.

The combination of vetch, plus getting organic matter up near 4.0, he hopes will significantly reduce nitrogen use in soybeans and corn. “We know we get about 250 pound of nitrogen uptake from the cover crops. If we can make half that available for grain crops planted into the stubble, we will be able to save significant money on fertilizer,” Davis says.

The carbon to nitrogen ratio for rye is about 50:1, compared to less than 20:1 for vetch. It is clear, Davis stresses, that vetch breaks down quickly and releases high rates of nitrogen. Keeping nitrogen in the soil and making a high percentage of it available to subsequent crops is the trick.

TAGS: Management
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