By JOHN O'CONNELL
No-till sugar beets can be grown in Idaho without sacrificing yields, increasing fertilizer rates or compromising weed control, according to results of an ongoing experiment at the University of Idaho's Kimberly Research & Extension Center.
Weed scientist Don Morishita is in his third season of the trials, comparing conventional planting with strip-till and no-till systems.
Sugar beet seeds resistant to the herbicide glyphosate have enabled many growers in Idaho to implement strip-till systems, leaving untilled stubble between their seed rows. But only a few have completely eliminated tillage. Reducing tillage saves on fuel and labor of running tillage equipment. The left-over crop residue also protects fields from wind erosion and water loss.
"Now with all of the growers comfortable using (glytphosate) in sugar beets, I think maybe this is a natural progression," Morishita said.
Rupert grower Duane Grant, chairman of Snake River Sugar Co-op, is in his sixth season of strip-till planting, which has allowed him to utilize sandy soils where wind erosion previously made beets too risky.
"In idaho it's an unanswered question whether no-till sugar beets will work well," Grant said. "To the extent Don's work shows full-on no-till sugar beets are viable and there's a net economic gain to going that direction, I think growers will follow his research carefully and begin to adapt to it."
Rupert grower Steve Maier, who started strip-till planting to protect beets in sandy soil, strip-tills 90 percent of his beets.
"It's saving us quite a bit of money because we don't have to plow and harrow," Maier said.
UI Extension irrigation specialist Howard Neibling calculated Morishita's strip-tilled fields have used 1.5 inches less water than conventional fields because of reduced evaporation and stubble preventing run-off. He'll take his first water measurements from no-till fields this season and predicts a 3-inch water savings over conventional tillage, mostly early in the season.
During some years, Neibling acknowledged, no-till may dry slowly, delaying sugar beet planting. Grant also has concerns about compaction in untilled soil limiting emergence, the lack of furrows for harvesters to follow without tillage and frost susceptibility of colder soils insulated by stubble.
Morishita has experienced no problems due to soil compaction. He's used flags to guide his harvester, which would be tough on a large scale, and his research hasn't delved into the frost problem.
Morishita has a graduate student analyzing costs associated with each system.
In the initial year of his trial, no-till yields were down two tons per acre versus the other methods.
Morishita explained fertilizer applied on top of his soil wasn't reaching seed in time to get plants started in no-till fields. In the second year, he used an injection system to apply fertilizer beside and below seed and saw comparable yields under all three systems.
This season, he injected fertilizer in all of the tillage scenarios.
For weed control, he used two post-emergence glyphosate applications, rather than the usual three applications, and mixed another mode of action with his second glyphosate treatment. He believes it's important to use multiple modes of action to prevent glyphosate resistance in weeds so the herbicide will remain a tool for no-till farmers into the future.
Morishita, who worried stubble would "tie up" herbicides, said his no-till weed control has been just as effective as conventional.