EDITOR'S NOTE — Organizers of the Farm Press Peanut Profitability Award have reviewed production data from previous winners to arrive at a “Top 10 Keys to Peanut Profitability.” This list of successful production practices will be presented in descending order during the next several months in issues of Southeast Farm Press and on this website, with sponsorship provided by DuPont Crop Protection. The Peanut Profitability Award, based on production efficiency in whole-farm situations, is entering its 13th year and is administered by Marshall Lamb, research director for the National Peanut Research Laboratory, and his staff.
Reduced-tillage comes in at No. 8 and precision farming is listed as the No. 7 key to peanut profitability in the Southeast.
These keys are intrinsically tied, with new technology offering peanut growers ever-changing opportunities to be more precise in all areas of peanut production — none more so than with basic tilling of the soil.
Cost comparisons of peanuts versus corn and cotton still provide a comparative economic advantage for fiber and grain. To maximize profits and be more competitive with these traditional crops of the Southeast, peanut growers are going to need to refine all the cost inputs that go into producing their crop.
The concept of reduced-tillage peanuts isn’t new. Then Auburn University Agronomists Gale Buchanan and Dana Sturkie introduced the science of strip-tilling peanuts back in 1973.
A few years later Auburn Weed Scientist Glenn Wehtje added proven weed and grass management strategies to the concept, but it had been slow to take off, until large tracts of new peanut land came into production, primarily in South Carolina and Florida over the past few years.
In North Carolina, Peanut Specialist David Jordan says many long-time peanut growers remain cautious about tillage systems. “There is no getting around the fact most of our growers grow Virginia type peanuts, which are larger and inherently more difficult to dig,” he says.
“No-till, strip-till and stale seedbed offer alternatives to traditional methods. In strip-till, growers prepare a narrow band for planting. That helps with stand establishment.” He says the stale seedbed may be a good compromise between conventional and no-till.
Peanuts can be produced successfully with many different tillage systems, but in any system, they do better on a slight bed. On most soils, at least a 16-inch wide, flat bed is needed for optimum production. If land is disked flat, growers can throw up a bed with coulters on the planter.
Jordan warns that new growers interested in growing peanuts need to pay special attention to their soil type before making the decision to go with strip-tillage or other reduced-tillage systems.
“Heavy soils may prevent farmers from harvesting the entire crop they've made. “They need to be careful about the fields they select for conservation-tillage,” he says.
Wind damage can be a problem
“In sandier soils, Jordan notes, wind damage can be a significant problem. A wheat cover crop will often minimize wind damage on some of our sandier, lighter soils,” he adds.
Growers adopting reduced-tillage systems may need to devote more time to overall management of peanuts, particularly early in the season. This especially applies to weed management.
Selection and proper application timing of burndown herbicides is essential to providing a weed-free seedbed when peanuts emerge from the soil and begin early season grow-off.
Unfortunately, the heart of the peanut belt in the Southeast is too often also the heart of weed resistance, particularly Palmer amaranth resistance to glyphosate.
Though glyphosate is less widely used in peanut production systems than for cotton or soybeans, growers still need to be aware of their herbicide options for burndown and avoid using materials on peanuts that may be used in subsequent years on other crops.
Benefits of soil-incorporated herbicides will be minimized in reduced-tillage systems. Although some tillage can be performed in the strip-tillage operation, the degree of incorporation of herbicides is limited and often not uniform.
As more and more peanuts are grown in reduced-tillage systems, establishing adequate fertility levels, especially pH is critical. Movement of lime into the root zone may be slowed by using reduced-tillage systems, which can reduce both yield and quality of peanuts.
Quality can also be negatively affected by potassium. Growers need to be aware that potassium applied to the soil surface in reduced-tillage systems often doesn’t leach through the pegging zone of peanuts, and can delay or reduce calcium absorption by developing pegs.
Auburn University Plant Pathologist Austin Hagan has been tracking the affects of diseases on peanut production for the past 30 years or so. During his tenure, peanut tillage has changed dramatically, with varying impacts on disease management.
“Strip-tillage has been shown to have some strong advantages (including reduced soil erosion and reduced time and labor required for planting), but in some situations, yields have been disappointing.
“Unbiased tillage research is difficult to accomplish, but studies have consistently shown that peanuts grown in strip-till systems have less thrips damage and slightly less TSWV, which on-farm observations have confirmed,” he says.
Conservation-tillage, such as strip-tillage, can reduce the amount of disease in a peanut field. For a number of years it has been recognized that TSWV is less severe in strip-tilled than conventional-tilled fields.
In addition, leaf spot is also less severe in strip-tilled fields than in conventionally-tilled fields, so long as peanuts are not planted in consecutive years.
Although the exact mechanism is unknown, leaf spot onset is delayed in strip-till peanuts.
Conservation-tillage does not eliminate the need for fungicides to control leaf spot, but helps to insure added disease control from a fungicide program.
White mold pressure has not increased in strip-tillage above conventional-tillage, especially when peanuts are grown in rotation with cotton.
The Auburn researcher notes Rhizoctonia limb rot was not evaluated. However, cotton is a host for Rhizoctonia solani and the cotton debris would likely serve as a bridge between crops.
Mapping for precision
Use of aerial, infra-red and GPS technology can offset the trend of bigger farms and fewer farmers, by making farms smaller. Not physically smaller, but high tech soil maps can allow a farmer to make decisions based on small plots of land rather than large fields.
Daniel Fowler is a crop consultant in Weldon, N.C., and one of a few with an onboard computer in his truck. All a part of the high tech generation in which we live, he says.
Standing in middle of a 750 acre field, which is adjacent to the Roanoke River near Weldon, Fowler explains everything on the farm is zone sampled. He looks for crop response, clay galls, sandy spots in the soil and any other problem areas, and those are the first areas that are zoned out.
Then, he looks for soil types. And anything in aerial photography that shows differences in plant growth is his starting point for creating zones. In the 750 acre plot of land, he says, there will be an average of about three acres per sample.
“Compared to a 2.5 acre grid, I feel like I can have a little larger average sample size, because I’m breaking up the variability in the soil,” he says. All the topography maps are generated using GPS technology.
In an ongoing research project, a Clemson University research team, headed by Ag Engineer Ahmad Khalilian, at the Edisto Agricultural Research and Education Center in Blackville, S.C., has developed a variable rate application system that promises to make nematode management more efficient and more affordable.
Khalilian says the system, technically named Site Specific Nematicide Placement System, is ready for commercial deployment and use by farmers.
In tests at the research center in Blackville, John Mueller, a long-time plant pathologist and now head of the Edisto Research Center, says, “We varied from zero Telone II to four gallons per acre in the same field.
“Without variable rate technology, the grower would typically treat for the highest nematode populations, using the higher rate of nematicide across the entire field. As the nematode pressure goes up in a cotton field and the cost of pesticides goes up, the need for more precise application becomes increasingly cost effective,” Mueller says.
“In one field with variable soils, and subsequently variable nematode pressure, we increased yield by 55 pounds of lint per acre. But, we only averaged one half gallon of Telone II per acre, versus the standard uniform treatment of three gallons per acre.
“We saved $25 per acre on Telone II costs plus another $25 or so on increased lint yield.
“The cost differential is less dramatic in a Temik 15G-treated field, but still we saw a five percent yield increase and 34 percent lower nematicide usage,” Mueller adds.
Starving plants of needed water and at precise times in their development makes them more efficient users of irrigation water, contends former USDA peanut specialist Wilson Faircloth.
Cutting water application in half over five weeks saves 3-4 inches of water at a cost of $10 dollars per acre inch and even more than at $4-$5 a gallon for diesel in some years, Faircloth says.
In multi-year testing at the USDA sites in Georgia and Texas, the best peanut yields came when the plant got 25-50 percent of its water needs, compared to 100 percent of needs either by irrigation or by rainfall.
Faircloth refers to this water starving technique as prime acclimation.
“To further test the prime acclimation theory, we drought stressed peanut plants starting at day 75 after planting for three weeks. We looked at recovery and it was clear the planned stress actually stimulated the difference in the growth of the plant and boosted yields compared to the plants that had all the water they needed,” Faircloth says.