Submitted to: Agricultural Experiment Station Publication
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2001
Publication Date: 12/1/2001
Citation: Grift, T.E., Tekeste, M.Z., Raper, R.L. 2001. Resounding soil: aaes and ars researchers exploring acoustic compaction layer detection. Ala. Agr. Exp. Sta. Highlights of Agric. Res. 48(4). http://www.ag.auburn.edu/resinfo/highlightsonline/winter01/grift.html. Interpretive Summary: Determining the depth of soil layers that restrict root growth requires mulitiple insertions of a probe into the soil. This measurement can take extensive amounts of labor and time to adequately sample a field. A new sensor that is based on acoustics has been tested in the soil bins of the USDA-ARS National Soil Dynamics Laboratory. These tests showed promise in the sensor's ability to distinguish between increasing depths and increasing densities of soil. Further experiments and modifications are planned to improve the sensing ability of the acoustical sensor. Successful development of this device could enable tillage depth to be varied across fields and remove root-restricting layers without wasting tillage energy.
Technical Abstract: Measuring the depth of soil compaction has traditionally been done with a soil cone penetrometer, a labor-intensive and slow stop-and-go method of inserting a probe into the ground. Faster methods are needed for site-specific use of this information. A new sonic method of sensing soil compaction has been evaluated in the soil bins of the USDA-ARS National Soil Dynamics Laboratory. This method shows promise at a certain frequency of its acoustic spectrum of detecting various levels of increased soil density. It also showed acoustical differences based on the depth of its operation in a clay loam soil. These results may point to its future ability to determine the depth and degree of soil compaction in many different soils and in differing soil moisture conditions. The use of this sensor in conjunction with GPS information could enable tillage to be conducted to depths appropriate to remove soil compaction and provide an adequate root growth environment for plants.