ARS | Publication request: Proximal soil sensing: an effective approach for soil measurements in space and time

Submitted to: Advances in Agronomy
Publication Type: Review Article
Publication Acceptance Date: April 15, 2011
Publication Date: September 6, 2011
Citation: Viscarra Rossel, R.A., Adamchuk, V.I., Sudduth, K.A., Mckenzie, N.J., Lobsey, C. 2011. Proximal soil sensing: an effective approach for soil measurements in space and time. Advances in Agronomy. 113:237-282.

Technical Abstract: This chapter reviews proximal soil sensing (PSS). Our intent is for it to be a source of up-to-date information on PSS, the technologies that are currently available and their use for measuring key soil properties. We first define PSS and discuss the sampling dilemma. Using the range of frequencies in the electromagnetic spectrum as a framework, we describe a large range of technologies that can be used for PSS, including electrochemical and mechanical sensors, telemetry, geographic positioning and elevation, multisensor platforms, and core measuring and down-borehole sensors. Because soil properties can be measured with different proximal soil sensors we provide examples of the alternative techniques that are available for measuring important soil properties. We also indicate the developmental stage of technologies for PSS and the approximate cost of commercial sensors. Our discussion focuses on the development of PSS over the past 30 years and on its current state. Finally, we provide a short list of general considerations for future work and suggest that we need research and development to: (i) improve soil sampling designs for PSS, (ii) define the most suitable technique or combination of techniques for measuring key soil properties, (iii) better understand the interactions between soil and sensor signals, (iv) derive theoretical sensor calibrations, (v) understand the basis for local versus global sensor calibrations, (vi) improve signal processing, analysis and reconstruction techniques, (vii) derive and improve methods for sensor data fusion and (viii) explore the many and varied soil, agricultural and environmental applications where proximal soil sensors could be used. PSS provides soil scientists with effective ‘tools’ to learn more about soils. Proximal soil sensors allow rapid and inexpensive collection of precise, quantitative, high-resolution data, which can be used to better understand soil spatial and temporal variability. We hope that this review raises awareness about PSS to further its research and development, and to encourage the use of proximal soil sensors in different applications.