Machine to Test Soil Strength Technology Description: ARS researchers have developed a machine that can measure a field’s soil strength continuously. This device moves horizontally throughout the soil, measuring soil strength at various depths. Currently, farmers use a soil cone penetrometer to measure soil strength–a costly, and time consuming procedure. Typically measurements are conducted at a few locations within a field and the tillage depth is then set to exceed the deepest root restricting layer–a layer of compacted soil that prevents roots to stop growing downward into the soil. This invention is unique in that it is designed to be moved upward and downward in an cyclical manner as the field is sampled. An infinite number of depths are sampled and the depth to the root-restricting layer can be determined at specific sites within a field. Measuring soil compaction depth at these sites can be coupled with Global Positioning System (GPS) technology to create maps that could be used to adjust tillage depth. Using this device with site-specific tillage could potentially save the time required for sampling and processing. Soil sampling companies or implement manufacturers could develop this invention for commercial use. Farmers will benefit from this device. Reference: Please refer to USPN 6,647,799, "Soil Strength Measurement for Site-Specific Agriculture," which issued on November 18, 2003. Inventors: Randy L. Raper National Soil Dynamics Laboratory 411 S. Donahue Drive Auburn, AL 36832-5806 (334) 844-4654 / Fax: (334) 887-8597 rraper@ars.usda.gov Eric H. Hall Auburn University 411 S. Donahue Drive Auburn, AL 36832 (334) 887-4515