|Chung, Sun-Ok - NAT INST AG ENG, S KOREA|
Submitted to: Agricultural and Biosystems Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 15, 2005
Publication Date: April 1, 2006
Citation: Chung, S.O., Sudduth, K.A. 2005. On-the-go soil strength profile sensor to quantify spatial and vertical variations in soil strength. Agricultural and Biosystems Engineering. 6(2):39-46. Interpretive Summary: Precision agriculture aims both to minimize costs and environmental damage caused by agricultural activities and to maximize crop yield and benefits, all based on information collected at within-field locations. One factor that can vary considerably within fields and can also greatly affect crop yields is soil strength or compaction. Because of this, a quick and inexpensive compaction measurement device is needed by farmers and consultants. Addressing this need, we built an on-the-go sensor that can take measurements continuously while traveling across a field. The body of the sensor is a narrow vertical blade attached to a tractor hitch. Cutting tips extend forward from the front edge of the sensor blade to measure compaction at five depths. In field tests, we compared duplicate passes of sensor data collected next to each other. These readings were very similar, showing that the sensor could provide repeatable measurements of compaction. We developed procedures for processing and mapping data from the sensor and interpreted maps of sensor data with respect to other soil maps. This study showed the ability of our sensor to collect soil compaction data in field operating conditions and also showed that these data could be related to soil physical properties. This information will be useful to researchers working on soil compaction sensing, to companies seeking to commercialize compaction sensors, and to crop advisors interpreting data from compaction sensors.
Technical Abstract: Because soil compaction is a concern in crop production and environmental pollution, quantification and management of spatial and vertical variability in soil compaction (or soil strength) would be a useful aspect of site-specific field management. In this paper, a soil strength profile sensor (SSPS) that could take measurements continuously while traveling across the field was developed. The SSPS obtained data simultaneously at 5 evenly spaced depths up to 50 cm using an array of load cells, each of which was interfaced with a soil-cutting tip. Means of soil strength measurements collected in adjacent, parallel transects were not significantly different, confirming the repeatability of soil strength sensing with the SSPS. Maps created with sensor data showed spatial and vertical variability in soil strength. Depth to the restrictive layer was different for different field locations, and only 5 to 16% of the tested field areas were highly compacted.