Conservation-tillage is one thing in above-ground crops such as corn and cotton. But it's something else altogether in peanuts. “For many years, our package approach for peanuts recommended having a smooth, viable seedbed, slightly raised and free of debris,” says John Baldwin, University of Georgia Extension peanut specialist. “That was the traditional, conventional system for producing peanuts.”
Implementing a new farming practice such as conservation-tillage creates risks, says Baldwin. “Changing from conventional to conservation-tillage presents management challenges such as land selection, crop rotations, soil fertility and pest management,” he says.
Decisions and adjustments, he adds, require detailed work before planting the first peanut crop by conservation-tillage methods. Preparing fields at least one year in advance can mean the difference between success and failure.
Some conventional peanut production systems may require as many as nine tillage operations, notes Baldwin. A strip-tillage system, on the other hand, requires only one to two operations.
Other advantages of strip-tillage, he says, include fewer lesser cornstalk borers. “And there's definitely less tomato spotted wilt virus, whether or not we have a cover crop. That's a unique thing — we can go into corn stubble, cotton residue or weed fallow, and there will be less tomato spotted wilt virus,” he says.
Growing peanuts by any method should be a package approach planned to fit your particular farm and resources, says the agronomist. To reduce chances of failure and to insure the proper scheduling of production practices, growers should seek assistance from their county agent and NRCS before implementing conservation-tillage practices, he advises.
“In your planning phase, consider proper liming and fertilization programs, timing of spray applications, the proper calibration of equipment, and pest management plans,” says Baldwin. “Weed identification and mapping of fields are extremely important in selecting the proper herbicides for a given situation.”
Weather causes the greatest risk in row-cropping today and affects crop yields regardless of the cropping system used, he says.
“Weather patterns cannot be controlled, but the use of conservation-tillage — in many situations — may help insure better growing conditions and reduce soil erosion, nutrient leaching, inadequate moisture at planting time, drought stress, and labor problems.”
Conservation-tillage also helps to conserve energy, reduce soil compaction, improve the timing of crop planting and establishment, and reduce machinery investments.
“Before using conservation-tillage, growers must evaluate their own set of conditions, including soil types, crop rotations, managerial abilities and other resources.”
The timing of conservation-tillage practices sometimes is more critical than with conventionally-tilled peanuts because of the need to activate pre-plant herbicides, he says.
Cover crop management is an important factor in conservation-tillage peanuts, says Baldwin. “To minimize adverse physical interference with planting and biological interactions between seedling peanuts and cover crops, covers should be terminated three to four weeks before planting. As small grains flower and mature, they are more easily killed with the postemergence herbicides Gramoxone Extra, Roundup or Touchdown.
“When vegetation is eliminated early, interference with planter operation is minimized, and potential phytotoxic effects associated with vegetative decomposition are reduced. Also, green residue increases the chances of cutworms and other soil insects.”
Recent data from Florida showed soil temperatures to be 25 degrees cooler — 130 degrees versus 104 degrees — and plant temperatures to be 5 degrees cooler at 11 a.m. in strip-tillage situations where wheat was allowed to head-out before killing.”
Recent research, says Baldwin, has shown an advantage in yield, grade and incidence of tomato spotted wilt virus when plating peanuts in twin rows in conventional-tillage compared to single-row patterns. From 1999 to 2001, 13 locations compared strip-tillage to conventional peanuts planted following either oats or wheat.
Initially, single rows surpassed twin rows when planted by strip-tillage methods. “Adjustments were made to move the subsoilers in to 27 inches when planting on a 36-inch spacing. This compared the yield of both 7-inch and 9-inch twin rows. Both twin rows and strip-tillage with or without a cover crop have been shown to reduce the incidence of tomato spotted wilt virus.
“Putting twin rows and strip-tillage together have further reduced the incidence of the virus, but not to the extent that occurs under conventional planting methods.”
From 1999 to 2001, five peanut varieties — Georgia Green, AT 201, ViruGard, AT 1-1 and Georgia Hi-O/L — were planted at 13 Georgia locations in single and twin-row patterns and by strip-till and conventional methods.
When averaged over tillage, twin rows had significantly higher yield, grade and less tomato spotted wilt virus than single rows. Strip-till peanuts had less virus than conventionally planted varieties.
“Experience has shown, however, that if you don't adjust strip-tillage equipment to plant twin rows, it would be better to plant single-row patterns. Under conventional-tillage — with results on more than 20 peanut varieties under irrigation — twin rows have resulted in higher yield, grade and less tomato spotted wilt virus 99 percent of the time.”Planting conservation-tillage peanuts can be more difficult in heavy soils, says Baldwin. “We have to dig peanuts. And while we have excellent equipment, and reduced-tillage over time will help to mellow those soils, it's still more difficult on the heavier soils. Harvest loss is the major problem in heavy soils.”
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