A review of the high-frequency multi-channel analysis of surface wave method for proximal soil sensing

Authors: LU, ZHIQU - University Of Mississippi

Submitted to: The International Journal of Earth & Environmental Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/2021
Publication Date: 4/6/2021
Citation: Lu, Z. 2021. A review of the high-frequency multi-channel analysis of surface wave method for proximal soil sensing. The International Journal of Earth & Environmental Sciences. 6:180. https://doi.org/10.15344/2456-351X/2021/180.

Interpretive Summary: Measurements of soil properties are important during agricultural research, such as studies on irrigation efficiency and soil erosion. Methods that use sound to make the measurements have the advantage that they reduce the chance of the method causing inaccurate measurements due to direct contact with the soil. A special method called high-frequency multi-channel analysis of surface waves (HF-MASW) has been developed for soil measurements, and the method has been improved by using specific sensor spacing and data processing methods. This paper is a review that brings together previous research studies by the author and cooperators that were focused on the application of the HF-MASW method for measuring the location of soil profiles, studying the effect of weather on soils, capturing the effect of rain on the soil, imaging hard layers in the soil, and studying the compaction of soil in fields. The results of the studies demonstrate that the HF-MASW method can be used for soil measurements in future agricultural research efforts. The method will help researchers to gain valuable insights into how soils are affected by tilling with farm equipment and how they react to rainfall and irrigation. This can eventually lead to improved irrigation methods that save water and to tillage methods that reduce soil compaction, helping to reduce operating costs for farmers.

Technical Abstract: This paper reviews the development and applications of the high-frequency multi-channel analysis of surface waves method (HF-MASW) for proximal soil sensing. The HF-MASW method uses surface waves to noninvasively measure soil profile in terms of the shear (S) wave velocity as a function of depth. Recently, several practical techniques have been developed to enhance the HF-MASW method, including (1) the self-adaptive method using a variable sensor spacing configuration, (2) the phase-only signal processing, and (3) a nonlinear acoustic technique. Using this enhanced HF-MASW method, the S-wave velocity soil profiles from a few centimeters to a few meters were measured. Fundamentally, the S-wave velocity is related to soil mechanical and hydrological properties through the principle of effective stress. Therefore, the measured 2-dimeniaional S-wave velocity profile images can reflect the temporal and spatial variations of soils due to weather effects, geological anomalies, and anthropologic activities. In this paper, several HF-MASW applications were described, including (1) measuring soil profiles, (2) studying weather and seasonal effects, (3) capturing the instantaneous variations of soil profiles during rain events, (4) detecting and imaging fraigpan layers, and (5) studying and imaging farmland compaction. These studies demonstrated that the HF-MASW method can be used as an effective proximal soil sensing tool for agricultural and environmental applications.