You can call it no-till, strip-till, zone-till, ridge-till, mulch-till, zero-till or direct seeding. But in the South, it all boils down to managing your crop residue on the soil surface year-round.
“In the South, we deal strictly with no-till or strip-till, and both of these practices involve in-row subsoiling,” says Andy Page, district conservationist from Perry, Ga. Page represented the South during a panel discussion on conservation-tillage at the recent Beltwide Cotton Conferences in New Orleans.
The difference between no-till and strip-till, he says, is the difference in the width of soil that is disturbed. “In no-till, it's a very minimum width, with less than 3 inches of the soil being disturbed at planting. In strip-till, more than 3 inches but less than one-third of the row width is disturbed at planting,” says Page.
Cover crops are a staple of the Southern conservation-tillage system, he says. “We believe in cover crops in the South. In some cases, when the cover crop gets extremely high, we go over it with a roller. Usually, we use a chemical burndown for our cover crops. We don't think you can get too much of a cover crop,” he says.
No-till or strip-till cotton acreage has grown in Georgia from 31,320 acres or 6 percent of the total in 1993 to 447,223 acres or 34 percent of the total cotton acreage in 2002, according to Page.
“This past year, those acres jumped to 523,226 acres or 40 percent of the total cotton acreage in Georgia. And realistically speaking, a lot of the acres reported as being strip-tilled are being planted in last year's crop residue or winter weeds. But a lot of it is being done in cover crop residue,” he says.
Southern growers realize there are numerous benefits to using a cover crop in conservation-tillage systems, he adds.
The biggest obstacle to using conservation-tillage, says Page, is the mindset of growers. “A lot of old-timers like to smell that sweet smell you get whenever you turn the soil. But they're burning up the residue in the soil and releasing carbon into the air. They're smelling that carbon dioxide being released into the air. Conservation also looks different from conventional-tillage, and it takes some getting used to,” he says.
The conversion to conservation-tillage in Georgia hasn't always been easy, says Page. In south Georgia, growers have had to work with tight clay soils in some areas, he says, and it has caused problems.
“But we have an innovative group of farmers. All of the success we have experienced with conservation-tillage has been directly related to how well the farmers have made the adjustment. Their attitudes toward conservation-tillage have made it a success.”
A cover crop is especially beneficial for Georgia growers because of the amount of rainfall they receive each year, says Page. “We have, on average, 50 inches of rain per year. We don't always get it when we want it. But if we have a good straw cover on the ground, we can conserve our moisture and reduce our need for rainfall. We also have a lot of groundwater we can utilize for irrigation.”
Cover crops, says Page, can be planted with conventional drills or no-till drills. They also can be flown on, planted in standing stalks, or spread with a fertilizer spreader before digging peanuts.
“A key to drilling in a cover crop is to decide which way your rows will run the next year and always plant your cover crop at a slight angle to the way your rows will run. This makes it easier to deal with residue in the coming crop year.”
The bulk of Georgia's conservation-tillage farming is being practiced in the southern portion of the state, says Page. It is being done in cotton, corn, peanuts, soybeans, tobacco, corn and vegetables.
The long-term benefits of conservation-tillage, he says, includes carbon being stored in the soil. Soil quality changes can begin in two to three years, he adds.
“Through straight conservation-tillage, with no actual turning of the soil, we've been able to raise the residue level in our soils 3 percent to 3.5 percent in a three to four-year period.”
The benefits of conservation-tillage are similar regardless of the region of the country, says Page. “Even though we're going about it in a different way, we're all going after the same thing, and we're all getting the same results. As long as you're protecting the land and producing a crop, it doesn't matter.”
Conservation-tillage saves soil, fuel, time and labor, he says. In addition, it reduces the wear and tear on equipment. “Our growers say they're saving $20 to $40 per acre with conservation-tillage, and that's significant.”
Conservation-tillage, says Page, must be a systems approach, with many equally important parts. “You can't go out today and decide that you'll be doing conservation-tillage this next year. It's too late if you haven't already planned ahead. You must utilize nutrient management, pest management, and crop rotation in such a system. All of these factors come into play to make you effective in a conservation-tillage system.”