Ripening wheat on the Palouse hills of Washington. Click the image for more information about it.

Optical Sensors Help Farmers Find High-Quality Wheat

By David Elstein
December 17, 2004

Since buyers will pay a premium for high-quality wheat, farmers need to not only grow it, but also know which exact locations in their fields have the wheat that buyers desire. Over the past decade, an Agricultural Research Service (ARS) agronomist in Pendleton, Ore., has been testing various instruments that may one day help farmers quickly pinpoint the precise location of high-quality wheat.

Dan Long started testing wheat-quality measuring devices while teaching at Montana State University, and he has continued that work at the ARS Columbia Plateau Conservation Research Center in Pendleton. He is currently working with two firms to develop and test spectroscopic devices that use fiber optics and near-infrared light to measuring protein concentration of grain. Attached to a combine, the device measures the protein content of wheat during the harvesting operation.

Buyers want specific levels of protein, depending on how the wheat will be used. Bakers need high-protein wheat for making bread, but low-protein wheat is preferred for cakes, cookies and crackers.

In addition to protein, the optical sensors can measure fat, oil, carbohydrate and moisture levels in grain. By knowing this information, farmers may one day be able to segregate grain during harvest and transfer operations, based on the grain's specific qualities. As with many other crops, a single field of wheat can produce grain with significant variations in quantity and quality.

Farmers can also use the sensor-derived information for fertilizer management, since soil nitrogen and protein levels are correlated. They will be able to tell which sections of the farm already have enough nitrogen. This information will help them save money on unnecessary fertilizer applications and also help protect the environment against surplus nitrogen.

Long will continue testing for grain quality next year and also hopes to use information from the optical sensors to study crop residue levels. The sensors probably will not be commercially available for another year or two, according to Long.

ARS is the U.S. Department of Agriculture's chief scientific research agency.