AmericanFarm.com

Hill experimenting to get the most out of his cover

By WHITNEY PIPKIN
AFP Correspondent

ROCK HALL, Md. (July 26, 2016) — Grain growers in Maryland have been growing cover crops for decades, thanks in part to a state incentive program aimed at improving water quality.
The crops, commonly rye or wheat, provide a continually green cover for the soil after corn or soybeans are harvested, keeping nutrients from washing away to the Chesapeake Bay over the winter.
But one Kent County farmer says cover crops are doing far more for his soils — and his bottom line — than they get credited.
“I’ve learned I’m making money on cover crops,” said Trey Hill, 41, and a fourth-generation. “I think they’re really benefitting us, and we’re starting to see soil health.”
Almost all of the more than 12,000 acres Hill farms in Maryland’s Kent, Cecil and Talbot counties with his father, Herman Hill, Jr., are planted in cover crops. And he takes it a step further.
Six years ago, he said his team didn’t get to spraying a few fields to kill the cover crop that had been growing all winter. So, unlike every other year, they planted corn into a sea of green.
Their machines didn’t break and, soon, Hill noticed that this style of planting came with additional yields, at least anecdotally. Each year, he started planting more acres this way, skipping a step and gaining a perceived advantage.
Now, he’s participating in a research project with a University of Maryland professor to add the data to his hunch that this type of planting is better for both business and the soils.
“We really need to find systems that work for both the environment and the farmer’s profitability,” said Dr. Ray Weil, a professor of environmental science and technology at the University of Maryland. “If, in the long term, it’s not going to help the farmer make money, or at least not cost money, it’s not something he’ll be able to do without subsidies.” 
More than keeping nitrogen out of the Bay, Weil thinks cover crops can make farming more profitable and efficient — and that they should be marketed to farmers for those benefits. But he wants the data to speak for itself and, perhaps, convince farmers that the earlier — and longer — they have cover crops in the ground, the better.
He’s conducting experiments to that end at Hill’s farm and a half-dozen others. Weil’s hypothesis is that there’s a pocket of nitrogen located deeper in the soil than the shallow roots of most cover crops can reach, allowing it to wash away. But, if those crops were planted earlier in the season — and allowed to linger even as the cash crops are planted — they could tap into that extra fertilizer and, perhaps, bring it up for nascent corn or soybeans to use.
The experiments at Hill’s farm look at which mix of cover crops do that the best. Tillage radishes that can pull nitrogen from six feet under and die on their own can be good precursors for corn, but do they relinquish that nitrogen at the right time to deliver the most benefit to the cash crop?
Maryland paid farmers $24 million last year to get them to plant a record 475,560 acres in cold-hardy cereal grains such as wheat, rye and barley, according to Julie Oberg, spokeswoman for the Maryland Department of Agriculture.
Maryland agriculture officials estimate that the cover crops planted in the program prevented more than 2.8 million pounds of nitrogen and 95,000 pounds of phosphorous from entering waterways last year.
The program allows farmers to kill the cover crops as early as March 1, but Weil said most of the soil benefits are found in letting them linger as long as possible. Many of the cover crops do their best growth — and nitrogen recovery — into April as they continue to add organic matter, activate the soils and make the water cycle more efficient, he said.
Hill said the experiment on several strips of land at his farm is already revealing the yields that cover crops can return.
When only the cover crops were growing in February and March, Weil and a group of his students used lysometers to measure the amount of nitrogen flowing through the groundwater below them. They found little difference between various mixes of cover crops so far, but all of them absorbed four times the volume of nitrates as the rows with no cover crop at all.
For Hill, that confirms the good work that cover crops are doing for his business. For Weil, it stokes his hope that cover crops have a long future in Maryland and the Mid-Atlantic region — with or without the paid incentive.