Crop rotation can increase spud yields, improve quality
By JOHN O'CONNELL
Idaho may always be famous for its potatoes, never to be confused as a Corn Belt state.
For the past two years, however, Gem State growers have planted more acres of corn than spuds. That trend will continue in 2012, unless potato growers increase planting from last year by more than 30,000 acres.
Even in Eastern Idaho, improved short-season hybrids and dairy and beef cattle demand have provided corn a niche.
Potato growers who add corn to rotations report slight yield increases and significant improvements in quality and size, thanks to soil benefits of corn residue. They can also pocket transportation savings when they sell to nearby cattle operations, which would otherwise import from out of state.
"It's becoming a lot more prevalent between American Falls and Rexburg. As these shorter-day varieties of corn come on line, and if they prove to be extremely robust on yield, you'll see a lot more corn coming in," American Falls potato grower Klaren Koompin, who will plant 850 corn acres this season, said. "It just shows there is obviously a huge demand in the state. We still don't raise 20 percent of what we consume."
Corn acres have steadily increased throughout the past decade, passing potatoes in 2010, when the state had 320,000 acres of corn compared with 295,000 acres of spuds. In 2011, Idaho farmers planted 350,000 corn acres, compared with 320,000 potato acres. This year, the USDA estimates corn planting will remain the same. Potato forecasts won't be available until midsummer, though Koompin doubts spuds will catch corn.
Koompin said growers in his area typically plant 81-day varieties, and his 10-year average is 170 bushels per acre. He said planting wheat between corn and spuds allows time for corn residue to break down, while helping wheat through improved moisture penetration.
Justin Skaar, whose family runs a Lewisville feedlot, grows 300 to 400 acres of high-moisture corn.
"The shorter-day varieties they've developed certainly fit into this Idaho growing season," said Skaar, acknowledging, "for gross dollars per acre, potatoes will always be the king."
Stan Gortsema, a retired University of Idaho Extension agent for Power County, first worked with corn in 1989, when he helped American Falls potato grower Jim Tiede experiment with 17 corn hybrids planted on a 15-acre pivot. Most reached maturity.
They worried they couldn't sufficiently dry their corn for storage. Then Snake River Cattle in American Falls agreed to purchase farmers' high-moisture corn. By 1990, 13 growers were selling to the feedlot, which now contracts for 3,500 Power County corn acres.
"A lot of the guys who sell corn to us, we supply their compost. It's a full circle," said Marshall Jensen, Snake River's general manager.
Tiede sees a slow increase in corn as long as the dairies are good and healthy.
U of I Extension cereal pathologist Juliet Marshall believes the down side to corn in Idaho is that it harbors fusarium head blight, a disease that damages wheat and barley. She's noticed an increase in head blight, which she attributes partly to the rise in corn acreage.