July 26, 2011 at 3:24 PM ET
Plowshares coated with the same diamond-like carbon material used to protect computer hard discs could allow farmers to save on fuel costs and improve the quality of their soils, according to German researchers.
The slippery material "reduces the friction between soil and the plow," Martin Hoerner, a physicist at the Fraunhofer Institute for the Mechanics of Materials in Freiberg who is working on the project, told me Tuesday via email.
Less friction means tractors that pull the plows need less power and fuel to till the soils, allowing farmers to drive lighter, more fuel efficient tractors.
German farmers consume about 2.6 million gallons of fuel a year to work their land but about 50 percent of the energy used when plowing is lost as a result of friction between the plowshare and the soil, according to the research team.
Their goal is to develop durable plows coated with the diamond-like carbon. So far Hoerner's team has reduced friction in half, which translated to a 30 percent reduction in the power the tractors need.
This power savings means farmers can use wider plows, digging up more soil at once and thus save time, or use smaller, lighter tractors, which cause less soil compaction.
"From the environmental point of view, it would be better for the tractors to be smaller," Hoerner, who is also a fruit farmer, noted in a news release about the experimental plowshares.
For example, lighter and smaller tractors mean less soil compaction. The looser the soil, the less power is needed to work it. Looser soils are also more hospitable to worms and other creatures that turn the soils and enrich it with nutrients.
What's more, compacted soils also are less able to absorb water and dry out more quickly.
So, if a slippery plowshare comes with all these potential benefits, why hasn't it been tried until now?
"It was not possible to produce coatings of this outstanding quality before," Hoerner explained to me. "Even now, we have problems with the lifetime" of the coating.
The problem is that the steel commonly used to make plows and other farming equipment deforms easily, thus causing the rigid, diamond-like carbon coating to flake off.
So, the researchers are testing out plowshares made of different materials including glass-fiber-reinforced plastic, tungsten carbide, and steel that has been hardened with nitrogen via a heating process called nitriding.
If the coating sticks to these more durable materials, the researchers note, the lifetime of the plowshares should be extended since the diamond-like carbon can withstand the abuse of being dragged through soil, sand, and rocks.
"We are still in the experimental phase," Hoerner noted. The next project goal is to plow at least 12 miles of ground before the coating fails. "If we achieve that, the wear-free plowshare will be within touching distance," he said.
More on farming technology: