Tillage based sensors are used to measure the soils mechanical resistance as the tillage instrument is pulled through the soil. The mechanical resistance is attributed to a number of soil failure types, such as cutting, breakage and displacement of the soil [4]. The resistance can be measured by monitoring the draft, but more commonly using strain gauges or load cells attached to the implement itself. The tillage implement can also be fitted with additional sensors e.g. acoustic, optical, capacitance and EC probes to measure additional soil attributes at depth.
Depth profiling is possible by using multiple strategically placed gauges along the length of the implement, or using multiple implements at staggered depths, or mechanically moving the implement throughout multiple depths as it is pulled through the soil.
The mechanical resistance can be used to infer soil properties such as compaction, water content, soil type and hard pan depth.
Depth profiling using multiple sensors [1] [2] [3].
Mapping of soil hard pan depth by measuring vertical forces and vertical actuation [4].
There are a number of underlying parameters that influence soil strength and so is a measurement correlative to a number of properties.
Research.
[5] A review of proximal sensing systems for measuring soil compaction.
1. Chung, S.O., Sudduth, K.A., Hummel, J.W., 2003. On-the-go soil strength profile sensor using a load cell array. ASAE Paper No. 031071. ASAE, St. Joseph, MI.
2. Chukwu, E., Bowers, C.G. Jr., 2005. Instantaneous multiple-depth soil mechanical impedance sensing from a moving vehicle, Trans. ASAE 48 (3), pp. 885-894
3. Adamchuk, V.I., Christenson, P.T., 2007. Development of an instrumented blade system for mapping soil mechanical resistance represented as a second-order polynomial, Soil and Tillage Research, Volume 95, Issues 1-2, Pages 76-83
4. Manor, G., Clark, R.L., 2001. Development of an instrumented subsoiler to map soil hard-pans and real-time control of subsoiler depth. ASAE Paper No. 011022. ASAE, St. Joseph, MI.
5. Hemmat, A., Adamchuk,V.I., 2008. Sensor systems for measuring soil compaction: Review and analysis, Computers and Electronics in Agriculture, Volume 63, Issue 2, Pages 89-103