A strategy of combining several different species in the cover crop in his no-till corn and soybean program is allowing Russell Hedrick of Hickory, N.C., to maximize the benefit he gets from the cover crop.
He has devised a mixed species “blend” of five different plants: cereal rye, triticale, oats, crimson clover and Daikon radishes. The goal is to create a cover that is well suited to the needs of his Piedmont soils.
The benefits he hopes to derive, in addition to limiting soil erosion, are to suppress winter annual weeds, scavenge excess nutrients from the preceding cash crop, and to improve the biological health of the soil. He also gets a rotational benefit from planting cool-season grasses and legumes after corn and soybeans.
“We get a lot better soil moisture retention with the blend, and the clover provides quite a bit of free nitrogen,” Hedrick said. “The cover crop itself is 100 percent a scavenger crop. We apply no fertilizer to it at all.”
He plants the cover crop using a no-till drill behind a tractor after he harvests his corn or soybeans. “We will let the blend grow to 36 to 48 inches in height, and then we will take an old cultipacker and roll it down,” he said. “That makes a 2-inch thick mat, which helps with weed control in the cash crop. The summer weeds can't come through that mat.”
He seeds at a rate per acre of 30 pounds of cereal rye, five pounds of crimson clover, 10 pounds of oats, 10 pounds of triticale and three pounds of radishes.
Running down the blend
What does each species bring to the blend? Lee Holcomb, NRCS District Conservationist for Catawba County, N.C., who helped Hedrick choose the elements, explains:
--Cereal rye establishes quickly in the field and is very winter hardy, and it can inhibit weed seed germination in the following crop.
--The oats are not as winter hardy, but they provide a good root system and plenty of organic material.
--Triticale is not as winter hardy as rye or oats but it serves some of the same purposes, such as scavenging excess nutrients and providing an abundance of organic material. And by including three different small grains, Hedrick increases his chances that at least one will survive no matter what the conditions.
--Crimson clover is very effective in producing nitrogen. Also, it can overwinter better than some other legumes. “It is really growing now,” Holcomb said when Southeast Farm Press visited the farm on March 26. “Hedrick may be able to reduce some of his nitrogen application on the next cash crop.”
--The Daikon radish has a huge taproot that helps break up the compaction layers created by heavy equipment and scavenges nitrogen and sulfur leftover from the previous cash crop, said Holcomb. “It acts as a form of biological tillage.”
Planting takes longer
The fall of 2013 was just the second year Hedrick has tried this approach, and he is still learning how to do deal with the huge amount of biomass the cover crop produces.
For instance, it took Russell a little longer than expected to plant soybeans in the cover crop because of the thick residue. He had to slow down to check seed placement, and it wound up taking two hours longer to plant the 36 acres than planned.
“We are able to plant right through the mat using a no-till coulters and floating row cleaners,” he said. “They make a seven-inch wide path for seed placement. That ensures better seed germination in the cash crop.”
A possibility in the future: Hedrick could get some cattle grazing from the cover crop, and the cattle manure would improve the microbial life of the soil.
There is one other benefit of the cover crop that Hedrick points to, which though intangible is definitely real: “I am doing this on rented land, and the land owners are happier because they don’t see their soil washing away over the winter.”
Field day set for May 9
If you would like to learn more about mixed species cover crops, plan on attending a field day that will be held Friday, May 9, 9 a.m. at JRH Grain Farms, 3230 Rocky Ford Rd. in Newton, N.C. The program will include these topics:
--Should you be growing mixed species cover crops?
--How do you modify farm equipment in order to plant into thick cover crop residues?
--What is the best “burndown” height for different cover crops and how do differences in total biomass affect weed control?
There will also be a “root pit”†to show how deep the cover crop extends its roots along with demonstrations of how to achieve soil health.
Lunch will be provided.
For more information, call the Catawba Soil & Water Conservation District Office at 828-465-8950 or visit Eventbrite.com and search “Western N.C. Soil Health Field Day in North Carolina.” Registration and lunch are free, but participants must register for the event in order to have an accurate head count for lunch. Pesticide credits and CCA credits will be available for those who attend.