Soil “Detective” Helps Farmers

Smearing the soil in farm fields during planting can make it tough for young corn plant roots to push their way through the soil. But a fiber optic sensor developed by scientists with USDA’s Agricultural Research Service could warn growers that smearing is happening. This would give the grower an opportunity to adjust equipment or change planting attachments.

The sensor was developed in studies led by Donald C. Erbach at ARS’ National Soil Dynamics Laboratory, Auburn, Ala.

Soil smearing is just what the name implies. As planting equipment sows crop seeds, the machinery rubs against the soil. This rubbing may smear the soil, forming a smooth, compact layer in the seed furrow.

This slick layer of soil slows air and water flow through the soil and restricts shoot and root growth. More pressure from the planter can mean more smearing. Since there’s no effective way to detect how much soil smearing the planter causes, it’s difficult to estimate crop losses.

The fiber optic sensor would serve as an alarm attached to the planter. The sensor projects a light beam onto the sidewall of the seed furrow and analyzes the reflected light for characteristics that indicates smearing. When the sensor detects soil smearing, it sends a signal to the grower.

ARS scientists are looking for partners to develop the fiber optic sensor technology for the marketplace. Their work on the sensor at Auburn, Ala., and Ames, Iowa, is part of the emerging high-tech field of precision agriculture--using new technology to help farmers conserve resources while improving their production efficiency.

Scientific contact: Donald C. Erbach, National Soil Dynamics Laboratory, Auburn, Ala., phone (334) 844-4741 (ext. 148), fax (334) 887-8597, derbach@eng.auburn.edu.