Like many no-tillers, Archer Ruffin believes in the value of micronutrients like zinc to get no-tilled corn off to a good start. But it may come as a surprise that Ruffin applies zinc in a two-pronged approach when planting corn.
Ruffin includes sulfur, boron and zinc in the 20% nitrogen he applies in a 2-by-2-inch placement. But at a cost of $2 to $2.25 per acre, he also adds 3 ounces of Wolf Trax zinc in the planter box for every bag of seed corn.
“We found that zinc can’t be used alone with liquid fertilizer,” says Ruffin, who farms by Charles City, Va. “It’s only been in the last 10 years that we’ve gone to using zinc in the planter box.”
A 2007 Virginia Tech University replicated field trial showed a 9-bushel-per-acre yield increase in corn when Wolf Trax zinc was added in the planter box, says David Moore, Virginia Tech Extension crop specialist.
“Wolf Trax was statistically better, yielding 126 bushels per acre compared to the untreated corn that yielded 117 bushels per acre,” Moore says. “The zinc levels in the soil were sufficient, but the phosphorus levels were very high, which sometimes makes zinc less available.”
But another 2007 field trial showed mixed results, Moore says.
“The trial average of the four replications was 5 bushels per acre better in favor of Wolf Trax zinc,” he says.
Two of the replications showed a yield increase for Wolf Trax and two did not.