Published May 19, 2006 | By Larry Reichenberger
Strip tillage may involve only a narrow band of soil on the surface, but its impact reaches far and wide. Researchers in the Great Plains are finding that strip till boosts water infiltration and root growth. Because of that, it improves the water-use efficiency of corn and other crops. In turn, that factor promises to prolong the economic stability of a region where the water supply is dwindling.
“With strip tillage, it looks like we’ve found a way to grow good corn with less water,” says Mike Petersen, a USDA-NRCS soil scientist at Greeley, Colo. “Our goal is to produce corn with 18 inches of water instead of the 28 to 30 inches that are now used. With strip tillage, we increase the rate of infiltration so less rainfall and irrigation water is lost. And, when combined with deep fertilization, roots are encouraged to venture deeper into the soil to utilize stored moisture and nutrients.”
More roots. After three years of work at the Irrigation Research Foundation farm in Yuma, Colo., Petersen has the numbers to prove that under strip till, roots grow deeper, longer, and more dense. In strip tillage, corn roots went a maximum of 74 inches deep and averaged 65 inches. By contrast, the roots of corn under conventional tillage reached an average depth of only 50 inches.
“The increased depth was matched by an increased lateral spread,” Petersen says. “In 2002, the roots from strip-till corn occupied 1.7 times more soil volume than roots from corn grown under conventional tillage. In 2003, strip-till roots occupied 1.2 times as much soil.”