South Carolina wheat producers are tailoring the tillage to fit their individual situations, and along the way they are finding there's more than one road to success.
“One of the things that interests me is that we have producers who are successful with different approaches in terms of land preparation and planting,” says Jay Chapin, Clemson University Extension small grains specialist.
In terms of land preparation, wheat production in the state ranges from conventional-tillage with drilling, and conventional-tillage with broadcasting to reduced-tillage with drilling. Each system has deep tillage in common, cracking the hardpan that limits small grain production in the Palmetto State. Seeding rate and proper planting depth are important considerations for the success of each of the systems.
South Carolina producers have increased the number of acres they broadcast in the last five years as precision equipment has become more available in the last five years.
“Some of the growers do deep tillage first, when they can identify where the old corn rows and the disk and incorporate the seed,” Chapin explains.
Seeding depth and rate are important for good stands. “There are more things that can go wrong with broadcasting wheat than with drilling, but we have growers who are doing a good job of managing the risk,” Chapin says. Growers are using precision fertilizer equipment to broadcast wheat.
Those growers, Chapin points out, calibrate their planters before heading to the field. He recommends calibrating seed on hard ground, where the seeds can be counted.
Seeding rates are based on row spacing. For broadcasting, 36 to 40 seed per square foot is recommended, assuming a 90-percent germination rate.
(Other seeding recommendations: 22 seed per row foot on 7-inch rows; 12 seed per row foot on 4-inch rows; 18 seed per row foot on 6-inch rows; and 24 seed per row foot on 8-inch rows.)
“The two hurdles to broadcasting wheat seed are uniform distribution and calibration,” Chapin points out. “Those are two operations that require precision and are two opportunities to make mistakes.”
There's a lot of diversity when it comes to using reduced-tillage in wheat production, Chapin says. Some producers use a one-pass approach, attaching the tillage equipment to the drill. Other growers use a separate deep-tillage operation before planting.
“Even with reduced-tillage, it's important to break up the hardpan,” Chapin says. “Some sort of deep tillage on Coastal Plain soils is necessary because the hardpan is one of the biggest limiting factors in small grain production.”
Trade-offs occur in reduced-tillage wheat production, Chapin says. Stemcounts can be more difficult to get because of the risk of cold injury. Growers have also reported an increase in tan spot in reduced-tillage systems.
“Stem counts can be more difficult to get because of the nitrogen demand to minimize the residue,” Chapin reports. As a result, wheat planted into heavy residue may be more susceptible to cold injury and stand loss, as was the case last winter.
Tan spot, a fungal disease that resembles leaf blotch, has increased in reduced-tillage fields, Chapin says. This fungal disease produces small, dark lesions with a yellow halo on the stem. The disease can be treated with all the recommended fungicides for wheat in South Carolina, Chapin says.
One benefit with reduced-tillage: Farmers can apply herbicides earlier in the winter to prevent early-season weed competition.
Whether it's reduced or conventional-tillage, “broadcast deep tillage is the key to high-yield wheat in the South Carolina Coastal Plain,” Chapin says. “Breaking the hardpan improves winter drainage and allows roots to reach nutrients and the subsoil to hold water better.”
Implements with curved shanks, such as Terramax and Paratill, provide “near-broadcast deep tillage,” Chapin says.
V-rippers with 20-inch spacing is another option. The straight shanks are lined up on the rows of the previous crop so the hardpan can be shattered.
“A firm seedbed is needed to control planting depth and this can be a difficult combination with deep tillage,” Chapin says.
Deep-tillage implements can also be used with a roller to firm and level the seedbed.
“All of these systems — the conventional with drilling, the conventional with broadcasting and the reduced-tillage with drilling — are only good if they fit the particular situation on-farm,” Chapin says. “We have farmers who are determined to use a system because it fits their needs. They're doing a good job of making it work.
“There isn't one system that's right for everyone,” Chapin says.