Abstract
Many agricultural and hydrological processes require the detailed knowledge of soil water content (SWC) in the vertical profile. Quantifying real-time and in situ SWC is difficult due to time, cost, toil, and technical issues. This paper describes the development of a multi-depth SWC monitoring sensor which can estimate the SWC from 4 vertical depths simultaneously. The probe is a type of electromagnetic (EM) sensor that indirectly measures the SWC on the basis of dielectric theory. The sensor was calibrated with soil samples of three distinct topographical locations. The calibration models were established by fitting linear order equations. The performance of the sensor was evaluated in situ field conditions. A multi-depth SWC curve was investigated to examine the impact of continuous estimations of SWC at specified depths on the sensor performance. The sensor was integrated with vertical interpolation technique to improve the measurement accuracy. The results indicated the optimal range of the SWC measurements, and the estimation error was less than 5%, except irrigation cycles. The linear fit coefficient of determination (R2) ranged from 0.957 to 0.993 and root mean square error (RMSE) was ranging from 1.565 to 4.456. The results showed that the sensor performed consistently better for at least 4 months within acceptable soil conditions. The sensor will be advantageous for continuous estimations of SWC, and managing the irrigation practices.
Highlights
The vertical distribution of soil water content (SWC) plays a significant role in various agricultural and hydrological processes (Pal, Maity, & Dey, 2016)
This study describes the development of a high-resolution integrated sensor for open and controlled environments, which can continuously measure the SWC from 4 vertical depths (0.20 to 0.80 m) simultaneously in different environmental and terrain conditions
This study presents a development of a multi-depth wireless SWC sensor based on the dielectric theory
Summary
The vertical distribution of SWC plays a significant role in various agricultural and hydrological processes (Pal, Maity, & Dey, 2016). The vertical profile of SWC is driven by various factors including; time, space, soil structure, type, dry and wet conditions, water holding capacity, meteorological conditions, vegetation, topography, and cropping cycle as well (Li, Shao, Jia, & Wei, 2016; Ojha, Morbidelli, Saltalippi, Flammini, & Govindaraju, 2014; Stewart, 1996; Western, Grayson, & Blöschl, 2002). The continuous monitoring of SWC at a classical point is very important because it varies significantly with depth. The precise estimation of SWC in the vertical profile becomes challenging (Holmes et al, 2012; Morbidelli, Corradini, Saltalippi, & Brocca, 2012; Ojha et al, 2014; Wang et al, 2015; Wilson et al, 2003). The performance of SWC monitoring devices has been tested for a wide variety of soil types in jas.ccsenet.org
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
