4/20/2013 7:00 AM
By Teresa McMinn Southeastern Pa. Correspondent
LANCASTER, Pa. — Duane Charles knelt to study a clump of earth and compare it with soil in his field at home.
“Mine’s drier,” said Charles, of East Donegal Township, Lancaster County, Pa.
Charles was at a recent cover crop field walk put on by Penn State Extension in Lancaster County.
Jeff Graybill, Extension agronomy educator, and Sjoerd Duiker, Penn State associate professor of soil management and applied soil physics, led the event, which was held at the Richard Rohrer farm in Manor Township, Lancaster County.
The field walk included various species — such as crimson clover, hairy vetch, huron and Aroostook rye, triticale, ryegrass and daikon radish — that were established in small plots in September.
Some were grown alone, some in combination with others.
“This is basically a three-year study,” Graybill said.
The cover crop demonstration and promotion project started in 2010 and was funded by a USDA Natural Resources Conservation Service innovation grant.
The study included roughly 10 small dairy farms across the state and used a no-till cover crop applied after corn silage on a series of research plots.
The project was geared to develop an outreach network for farmers and promote the use of cover crops.
Graybill said the Manor Township farm, owned by Richard Rohrer, included good soil and a great location for the Lancaster County study.
Some benefits from the overall study are tough to qualify because growing conditions vary from year to year, he said.
Additionally, there was variability from location to location in the way species performed, he said.
Planting times, weather and manure applications were also different from one site to another. Those factors make it tough to find the right formula, he said.
“It’s sort of trial and error,” Graybill said. “It’s a challenge sometimes getting a cover crop established in a timely manner.”
But the work can pay off with many advantages, he said.
In addition to growing more feed — primarily for dairy cows — a cover crop provides numerous benefits to the field, Graybill said.
“It stimulates organic matter, enhances soil,” he said.
Spring forage quality can also be very good.
“There are definite reasons for using the cover crops,” Duiker said.
Cover crops help absorb nitrates and help prevent runoff that could make its way to the Chesapeake Bay.
“Our waters get fertilized too much,” he said, adding that cover crops also help protect soil from erosion and reduce nutrient loss.
Duiker said the project studied which varieties would work with or against others. For example, if the soil is fertile, rye will compete with crimson, he said.
Combining species requires greater attention to detail, Duiker said as he held up a clump of ground that contained mostly rye grass.
“We want the soil to be occupied by roots and earthworms,” he said. “We want to improve the structure of the soil naturally.”