Review of Novel and Emerging Proximal Soil Moisture Sensors for Use in Agriculture
Abstract
:1. Introduction
- (i)
- explore the sensor and engineering literature to identify promising new opportunities for the development of soil moisture sensors for use in agriculture,
- (ii)
- identify opportunities to overcome soil and operational constraints to the use of existing soil sensors, through development of new sensing technologies, and
- (iii)
- seek opportunities to bridge the gap between technologists and the soil community who share a common desire for the development of new soil moisture sensing technology.
2. Advances in In Situ Invasive Matric Potential Sensors
3. Advances in In Situ Invasive Soil Moisture Sensors
3.1. Dielectric Constant Based Approaches
3.2. Time Domain Reflectometry (TDR)
3.3. Frequency Domain Reflectometry (FDR) and Capacitance
3.4. Radio Frequency Identification (RFID)
3.5. Invasive Open Ended Antenna (Radar) Microwave
3.6. In Situ Paired Transceiver Approaches
3.7. Seismoelectric Approaches
3.8. Heat Pulse
3.9. In Situ Fiber Optic Approaches
3.10. Hydrogels
4. Emerging Mobile and Noninvasive Soil Moisture Sensors
4.1. Cosmic Ray Sensors
4.2. Electromagnetic Induction (EMI)
4.3. Portable Optical Approaches (Vis-NIR, & NIR)
4.4. Microwaves and Ground Penetrating Radar (GPR)
4.5. Geographical Positioning Systems (GPS-IR, GNSS-IR)
5. Discussion
6. Conclusions
Funding
Acknowledgments
Conflicts of Interest
References
- Clothier, B.E.; Hall, A.J.; Deurer, M.; Green, S.R.; Mackay, A.D. Soil Ecosystem Services: Sustaining Returns on Investment into Natural Capital. In Sustaining Soil Productivity in Response to Global Climate Change: Science, Policy, and Ethics; John Wiley & Sons, Inc.: West Sussex, UK, 2011; pp. 117–139. [Google Scholar] [CrossRef]
- Tuller, M.; Babaeian, E.; Jones, S.; Montzka, C.; Sadeghi, M.; Vereecken, H. The Paramount Societal Impact of Soil Moisture. Eos 2019, 100. [Google Scholar] [CrossRef]
- Babaeian, E.; Sadeghi, M.; Jones, S.B.; Montzka, C.; Vereecken, H.; Tuller, M. Ground, Proximal, and Satellite Remote Sensing of Soil Moisture. Rev. Geophys. 2019, 57, 530–616. [Google Scholar] [CrossRef] [Green Version]
- Fischer, G.; Tubiello, F.N.; van Velthuizen, H.; Wiberg, D.A. Climate change impacts on irrigation water requirements: Effects of mitigation, 1990–2080. Technol. Forecast. Soc. Chang. 2007, 74, 1083–1107. [Google Scholar] [CrossRef] [Green Version]
- Viscarra Rossel, R.A.; Adamchuk, V.I. Ch 6: Proximal Soil Sensing. In Precision Agriculture for Sustainability and Environmental Protection Edition: 1; Oliver, M., Bishop, T., Marchant, B., Eds.; Earthscan: Oxford, UK, 2013; p. 304. [Google Scholar]
- Kang, C.S.; Kanniah, K.D.; Alvin Lau, M.S. Microwave remote sensing for soil moisture estimation in tropical regions—A review and SMOS L2 products validation. Int. J. Geoinform. 2016, 12, 9–16. [Google Scholar]
- Peng, J.; Loew, A.; Merlin, O.; Verhoest, N.E.C. A review of spatial downscaling of satellite remotely sensed soil moisture. Rev. Geophys. 2017, 55, 341–366. [Google Scholar] [CrossRef]
- Srivastava, P.K. Satellite Soil Moisture: Review of Theory and Applications in Water Resources. Water Resour. Manag. 2017, 31, 3161–3176. [Google Scholar] [CrossRef]
- Montagu, K.D.; Stirzaker, R.J. Why do two-thirds of Australian irrigators use no objective irrigation scheduling methods. WIT Trans. Ecol. Environ. 2008, 112, 95–103. [Google Scholar] [CrossRef] [Green Version]
- Leib, B.G.; Hattendorf, M.; Elliott, T.; Matthews, G. Adoption and adaptation of scientific irrigation scheduling: Trends from Washington, USA as of 1998. Agric. Water Manag. 2002, 55, 105–120. [Google Scholar] [CrossRef]
- Wang, J.; Klein, K.K.; Bjornlund, H.; Zhang, L.; Zhang, W. Adoption of improved irrigation scheduling methods in Alberta: An empirical analysis. Can. Water Resour. J. 2015, 40, 47–61. [Google Scholar] [CrossRef]
- Susha Lekshmi, S.U.; Singh, D.N.; Shojaei Baghini, M. A critical review of soil moisture measurement. Meas. J. Int. Meas. Confed. 2014, 54, 92–105. [Google Scholar] [CrossRef]
- Shukla, M.K. Chapter 8: Water in the Vadose Zone. In Soil Physics An Introduction; Shukla, M.K., Ed.; CRC Press: Boca Raton, FL, USA, 2014; pp. 119–155. [Google Scholar]
- Oates, M.J.; Fernández-López, A.; Ferrández-Villena, M.; Ruiz-Canales, A. Temperature compensation in a low cost frequency domain (capacitance based) soil moisture sensor. Agric. Water Manag. 2017, 183, 86–93. [Google Scholar] [CrossRef]
- Dobriyal, P.; Qureshi, A.; Badola, R.; Hussain, S.A. A review of the methods available for estimating soil moisture and its implications for water resource management. J. Hydrol. 2012, 458–459, 110–117. [Google Scholar] [CrossRef]
- Romano, N. Soil moisture at local scale: Measurements and simulations. J. Hydrol. 2014, 516, 6–20. [Google Scholar] [CrossRef]
- Marshall, T.J.; Holmes, J.W.; Rose, C.W. Measurement of water content and potential. In Soil Physics, 3th ed.; Marshall, T.J., Holmes, J.W., Rose, C.W., Eds.; Cambridge University Press: Cambridge, UK, 1996; pp. 54–78. [Google Scholar] [CrossRef]
- Sciroot. Sciroot: The Root of Precise Irrigation. Available online: https://www.sciroot.ag/ (accessed on 30 November 2020).
- Meter. Metos 21 Manual; Meter Group: Pullman, WA, USA, 2017. [Google Scholar]
- Walthert, L.; Schleppi, P. Equations to compensate for the temperature effect on readings from dielectric Decagon MPS-2 and MPS-6 water potential sensors in soils. J. Plant Nutr. Soil Sci. 2018, 181, 749–759. [Google Scholar] [CrossRef]
- Mancuso, C.; Papa, R. A high capacity tensiometer to measure soil suction. In Proceedings of the 20th IMEKO TC4 Symposium on Measurements of Electrical Quantities: Research on Electrical and Electronic Measurement for the Economic Upturn, Together with 18th TC4 International Workshop on ADC and DCA Modeling and Testing, IWADC 2014, Sannio Beneveto, Italy, 15–17 September 2014; pp. 212–215. [Google Scholar]
- Mendes, J.; Gallipoli, D.; Boeck, F.; Von Unold, G.; Tarantino, A. Building the UPPA high capacity tensiometer. In E3S Web of Conferences; EDP Sciences: Paris, France, 2016. [Google Scholar]
- Mendes, J.; Gallipoli, D. Comparison of high capacity tensiometer designs for long-term suction measurements. Phys. Chem. Earth 2020, 115, 102831. [Google Scholar] [CrossRef]
- Rojas, J.C.; Pagano, L.; Zingariello, M.C.; Mancuso, C.; Giordano, G.; Passeggio, G. A new high capacity tensiometer: First results. In Proceedings of the 1st European Conference on Unsaturated Soils, E-UNSAT 2008, Durham, UK, 2–4 July 2008; pp. 205–211. [Google Scholar]
- Robinson, D.A.; Campbell, C.S.; Hopmans, J.W.; Hornbuckle, B.K.; Jones, S.B.; Knight, R.; Ogden, F.; Selker, J.; Wendroth, O. Soil moisture measurement for ecological and hydrological watershed-scale observatories: A review. Vadose Zone J. 2008, 7, 358–389. [Google Scholar] [CrossRef] [Green Version]
- Bobrov, P.P.; Belyaeva, T.A.; Kroshka, E.S.; Rodionova, O.V. Soil moisture measurement by the dielectric method. Eurasian Soil Sci. 2019, 52, 822–833. [Google Scholar] [CrossRef]
- Topp, G.C.; Davis, J.L.; Annan, A.P. Electromagnetic determination of soil water content: Measurements in coaxial transmission lines. Water Resour. Res. 1980, 16, 574–582. [Google Scholar] [CrossRef] [Green Version]
- Goorahoo, D.; Sharma, F.C.; Adhikari, D.D.; Benes, S.E. Chapter 3: Soil Water Plant Relations. In Irrigation, 6th ed.; Stetson, L.E., Mecham, B.Q., Eds.; Irrigation Association: Falls Church, VA, USA, 2011. [Google Scholar]
- Henggeler, J.C.; Dukes, M.D.; Mecham, B.Q. Chapter 13: Irrigation Sceduling. In Irrigation, 6th ed.; Stetson, L.E., Mecham, B.Q., Eds.; Irrigation Association: Falls Church, VA, USA, 2011. [Google Scholar]
- Kelleners, T.J.; Robinson, D.A.; Shouse, P.J.; Ayars, J.E.; Skaggs, T.H. Frequency dependence of the complex permittivity and its impact on dielectric sensor calibration in soils. Soil Sci. Soc. Am. J. 2005, 69, 67–76. [Google Scholar] [CrossRef]
- Grisso, R.; Alley, M.; Holshouser, D.; Thomason, W. Precision Farming Tools: Soil Electrical Conductivity; Virginia Polytechnic Institute and State University: Blacksburg, VA, USA, 2009. [Google Scholar]
- Kargas, G.; Soulis, K.X. Performance evaluation of a recently developed soil water content, dielectric permittivity, and bulk electrical conductivity electromagnetic sensor. Agric. Water Manag. 2019, 213, 568–579. [Google Scholar] [CrossRef]
- Saeed, I.A.; Wang, M.; Ren, Y.; Shi, Q.; Malik, M.H.; Tao, S.; Cai, Q.; Gao, W. Performance analysis of dielectric soil moisture sensor. Soil Water Resour. 2019, 14, 195–199. [Google Scholar] [CrossRef] [Green Version]
- Vereecken, H.; Huisman, J.A.; Bogena, H.; Vanderborght, J.; Vrugt, J.A.; Hopmans, J.W. On the value of soil moisture measurements in vadose zone hydrology: A review. Water Resour. Res. 2010, 46. [Google Scholar] [CrossRef] [Green Version]
- Ito, Y.; Chikushib, J.; Miyamotoc, H. Multi-TDR probe designed for measuring soil moisture distribution near the soil surface. In Proceedings of the 19th World Congress of Soil Science, Soil Solutions for a Changing World, Brisbane, Australia, 1–6 August 2010. [Google Scholar]
- Adelakun, I.A.; Sri Ranjan, R. Design of a multilevel TDR probe for measuring soil water content at different depths. Trans. Asabe 2013, 56, 1451–1460. [Google Scholar] [CrossRef]
- ESI. Environmental Sensors. Available online: https://www.esica.com/_docs/tb01.pdf (accessed on 30 November 2020).
- Serrarens, D.; MacIntyre, J.L.; Hopmans, J.W.; Bassoi, L.H. Soil moisture calibration of TDR multilevel probes. Sci. Agric. 2000, 57, 349–354. [Google Scholar] [CrossRef] [Green Version]
- Woszczyk, A.; Szerement, J.; Lewandowski, A.; Kafarski, M.; Szypłowska, A.; Wilczek, A.; Skierucha, W. An open-ended probe with an antenna for the measurement of the water content in the soil. Comput. Electron. Agric. 2019, 167. [Google Scholar] [CrossRef]
- Thompson, R.B.; Gallardo, M.; Fernández, M.D.; Valdez, L.C.; Martínez-Gaitán, C. Salinity effects on soil moisture measurement made with a capacitance sensor. Soil Sci. Soc. Am. J. 2007, 71, 1647–1657. [Google Scholar] [CrossRef]
- Nagahage, E.A.A.D.; Nagahage, I.S.P.; Fujino, T. Calibration and validation of a low-cost capacitive moisture sensor to integrate the automated soil moisture monitoring system. Agriculture 2019, 9, 141. [Google Scholar] [CrossRef] [Green Version]
- González-Teruel, J.D.; Torres-Sánchez, R.; Blaya-Ros, P.J.; Toledo-Moreo, A.B.; Jiménez-Buendía, M.; Soto-Valles, F. Design and calibration of a low-cost SDI-12 soil moisture sensor. Sensors 2019, 19, 491. [Google Scholar] [CrossRef] [Green Version]
- Mizuguchi, J.; Piai, J.C.; De França, J.A.; De Morais França, M.B.; Yamashita, K.; Mathias, L.C. Fringing field capacitive sensor for measuring soil water content: Design, manufacture, and testing. IEEE Trans. Instrum. Meas. 2015, 64, 212–220. [Google Scholar] [CrossRef]
- Kojima, Y.; Shigeta, R.; Miyamoto, N.; Shirahama, Y.; Nishioka, K.; Mizoguchi, M.; Kawahara, Y. Low-cost soil moisture profile probe using thin-film capacitors and a capacitive touch sensor. Sensors 2016, 16, 1292. [Google Scholar] [CrossRef]
- Da Costa, E.F.; de Oliveira, N.E.; Morais, F.J.O.; Carvalhaes-Dias, P.; Duarte, L.F.C.; Cabot, A.; Dias, J.A.S. A self-powered and autonomous fringing field capacitive sensor integrated into a micro sprinkler spinner to measure soil water content. Sensors 2017, 17, 575. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Goswami, M.P.; Montazer, B.; Sarma, U. Design and Characterization of a Fringing Field Capacitive Soil Moisture Sensor. IEEE Trans. Instrum. Meas. 2019, 68, 913–922. [Google Scholar] [CrossRef]
- Saeed, I.A.; Qinglan, S.; Wang, M.; Butt, S.L.; Zheng, L.; Tuan, V.N.; Wanlin, G. Development of a low-cost multi-depth real-time soil moisture sensor using time division multiplexing approach. IEEE Access 2019, 7, 19688–19697. [Google Scholar] [CrossRef]
- Rusu, C.; Krozer, A.; Johansson, C.; Ahrentorp, F.; Pettersson, T.; Jonasson, C.; Rösevall, J.; Ilver, D.; Terzaghi, M.; Chiatante, D.; et al. Miniaturized wireless water content and conductivity soil sensor system. Comput. Electron. Agric. 2019, 167, 105076. [Google Scholar] [CrossRef]
- Deng, X.; Gu, H.; Yang, L.; Lyu, H.; Cheng, Y.; Pan, L.; Fu, Z.; Cui, L.; Zhang, L. A method of electrical conductivity compensation in a low-cost soil moisture sensing measurement based on capacitance. Meas. J. Int. Meas. Confed. 2020, 150, 107052. [Google Scholar] [CrossRef]
- Pichorim, S.F.; Gomes, N.J.; Batchelor, J.C. Two solutions of soil moisture sensing with rfid for landslide monitoring. Sensors 2018, 18, 452. [Google Scholar] [CrossRef] [Green Version]
- Boada, M.; Lazaro, A.; Villarino, R.; Girbau, D. Battery-less soil moisture measurement system based on a nfc device with energy harvesting capability. IEEE Sens. J. 2018, 18, 5541–5549. [Google Scholar] [CrossRef]
- da Fonseca, N.S.; Freire, R.C.; Batista, A.; Fontgalland, G.; Tedjini, S. A passive capacitive soil moisture and environment temperature UHF RFID based sensor for low cost agricultural applications. In Proceedings of the SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), Aguas de Lindoia, Brazil, 27–30 August 2017. [Google Scholar]
- Boada, M.; Lazaro, A.; Villarino, R.; Gil, E.; Girbau, D. Near-field soil moisture sensor with energy harvesting capability. In Proceedings of the 2018 48th European Microwave Conference, EuMC 2018, Madrid, Spain, 23–27 September 2018; pp. 235–238. [Google Scholar]
- Hardie, M.; Hoyle, D. Underground wireless data transmission using 433-MHz LoRa for agriculture. Sensors 2019, 19, 4232. [Google Scholar] [CrossRef] [Green Version]
- Vuran, M.C.; Salam, A.; Wong, R.; Irmak, S. Internet of underground things in precision agriculture: Architecture and technology aspects. Ad Hoc Netw. 2018, 81, 160–173. [Google Scholar] [CrossRef] [Green Version]
- Kabir, H.; Khan, M.J.; Brodie, G.; Gupta, D.; Pang, A.; Jacob, M.V.; Antunes, E. Measurement and modelling of soil dielectric properties as a function of soil class and moisture content. J. Microw. Power Electromagn. Energy 2020, 54, 3–18. [Google Scholar] [CrossRef]
- Berardinelli, A.; Luciani, G.; Crescentini, M.; Romani, A.; Tartagni, M.; Ragni, L. Application of non-linear statistical tools to a novel microwave dipole antenna moisture soil sensor. Sens. Actuators A Phys. 2018, 282, 1–8. [Google Scholar] [CrossRef]
- Oliveira, J.G.D.; Pinto, E.N.M.G.; Neto, V.P.S.; D’assunção, A.G. CSRR-based microwave sensor for dielectric materials characterization applied to soil water content determination. Sensors 2020, 20, 255. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Xu, Y.; Li, J.; Duan, J.; Song, S.; Jiang, R.; Yang, Z. Soil water content detection based on acoustic method and improved Brutsaert’s model. Geoderma 2020, 359, 114003. [Google Scholar] [CrossRef]
- Adamo, F.; Andria, G.; Attivissimo, F.; Giaquinto, N. Soil moisture measurement with acoustic methods. In Proceedings of the 12th IMEKO TC4 International Symposium Electrical Measurements and Instrumentation, Zagreb, Croatia, 25–27 September 2002; pp. 239–244. [Google Scholar]
- Adamo, F.; Andria, G.; Attivissimo, F.; Giaquinto, N. An acoustic method for soil moisture measurement. IEEE Trans. Instrum. Meas. 2004, 53, 891–898. [Google Scholar] [CrossRef]
- Attivissimo, F.; Cannazza, G.; Cataldo, A.; De Benedetto, E.; Fabbiano, L. Enhancement and metrological characterization of an accurate and low-cost method based on seismic wave propagation for soil moisture evaluation. IEEE Trans. Instrum. Meas. 2010, 59, 1216–1223. [Google Scholar] [CrossRef]
- Adamo, F.; Attivissimo, F.; Fabbiano, L.; Saving, M. Improvements of seismic sensor design for soil moisture measurement. In Proceedings of the 18th IMEKO World Congress 2006: Metrology for a Sustainable Development, Rio de Janeiro, Brazil, 17–22 September 2006; pp. 1740–1745. [Google Scholar]
- Dong, X.; Vuran, M.C. Impacts of soil moisture on cognitive radio underground networks. In Proceedings of the 2013 1st International Black Sea Conference on Communications and Networking, BlackSeaCom 2013, Batumi, Georgia, 3–5 July 2013; pp. 222–227. [Google Scholar]
- Salam, A. An underground radio wave propagation prediction model for digital agriculture. Information 2019, 10, 147. [Google Scholar] [CrossRef] [Green Version]
- Vuran, M.C.; Silva, A.R. Communication through soil in wireless underground sensor networks—Theory and practice. In Sensor Networks. Signals and Communication Technology; Springer: Berlin/Heidelberg, Germany, 2009; pp. 309–347. [Google Scholar]
- Silva, A.R.; Vuran, M.C. Empirical evaluation of wireless underground-to-underground communication in wireless underground sensor networks. In Proceedings of the International Conference on Distributed Computing in Sensor Systems, Marina del Rey, CA, USA, 25–27 May 2020; pp. 231–244. [Google Scholar]
- Salam, A.; Vuran, M.C.; Irmak, S. Di-Sense: In situ real-time permittivity estimation and soil moisture sensing using wireless underground communications. Comput. Netw. 2019, 151, 31–41. [Google Scholar] [CrossRef]
- Liedmann, F.; Wietfeld, C. SoMoS—A multidimensional radio field based soil moisture sensing system. In 2017 IEEE Sensors; IEEE: New York, NY, USA, 2017; pp. 1–3. [Google Scholar]
- Kong, Q.; Chen, H.; Mo, Y.L.; Song, G. Real-time monitoring ofwater content in sandy soil using shear mode piezoceramic transducers and active sensing—A feasibility study. Sensors 2017, 17, 2395. [Google Scholar] [CrossRef] [Green Version]
- Lo, W.C.; Yeh, C.L.; Tsai, C.T. Effect of soil texture on the propagation and attenuation of acoustic wave at unsaturated conditions. J. Hydrol. 2007, 338, 273–284. [Google Scholar] [CrossRef]
- Yamamoto, T.; Schuckman, B. Experiments and theory of wave-soil interactions. J. Eng. Mech. 1984, 110, 95–112. [Google Scholar] [CrossRef]
- Lo, W.C.; Sposito, G. Acoustic waves in unsaturated soils. Water Resour. Res. 2013, 49, 5674–5684. [Google Scholar] [CrossRef]
- Brutsaert, W. The propagation of elastic waves in unconsolidated granular mediums. J. Geophys. Res. 1969, 69, 243–257. [Google Scholar] [CrossRef]
- Adamo, F.; Attivissimo, F.; Fabbiano, L.; Giaquinto, N.; Spadavecchia, M. Soil moisture assessment by means of compressional and shear wave velocities: Theoretical analysis and experimental setup. Measurement 2010, 43, 344–352. [Google Scholar] [CrossRef]
- Adamo, F.; Andria, F.; Attivissimo, F.; Fabbiano, L.; Giaquinto, N. Soil moisture assessment by means of compressional and shear wave velocities: Theoretical analysis. In Proceedings of the IMTC Instrument and Measurement Technology Conference, Sorrento, Italy, 24–27 April 2006; pp. 647–650. [Google Scholar]
- Jouniaux, L.; Zyserman, F. A review on electrokinetically induced seismo-electrics, electro-seismics, and seismo-magnetics for Earth sciences. Solid Earth 2016, 7, 249–284. [Google Scholar] [CrossRef] [Green Version]
- Revil, A.; Barnier, G.; Karaoulis, M.; Sava, P.; Jardani, A.; Kulessa, B. Seismoelectric coupling in unsaturated porous media: Theory, petrophysics, and saturation front localization using an electroacoustic approach. Geophys. J. Int. 2013, 196, 867–884. [Google Scholar] [CrossRef] [Green Version]
- Holzhauer, J.; Brito, D.; Bordes, C.; Brun, Y.; Guatarbes, B. Experimental quantification of the seismoelectric transfer function and its dependence on conductivity and saturation in loose sand. Geophys. Prospect. 2017, 65, 1097–1120. [Google Scholar] [CrossRef] [Green Version]
- Dupuis, J.C.; Butler, K.E.; Kepic, A.W. Seismoelectric imaging of the vadose zone of a sand aquifer. Geophysics 2007, 72, A81–A85. [Google Scholar] [CrossRef] [Green Version]
- Schoemaker, F.C.; Smeulders, D.M.J.; Slob, E.C. Electrokinetic effect: Theory and measurement. In SEG Technical Program Expanded Abstracts 2008; Society of Exploration Geophysicists: Tulsa, OK, USA; Volume 27, pp. 1645–1649.
- Zyserman, F.I.; Monachesi, L.B.; Jouniaux, L. Dependence of shear wave seismoelectrics on soil textures: A numerical study in the vadose zone. Geophys. J. Int. 2017, 208, 918–935. [Google Scholar] [CrossRef]
- Strahser, M.; Jouniaux, L.; Sailhac, P.; Matthey, P.D.; Zillmer, M. Dependence of seismoelectric amplitudes on water content. Geophys. J. Int. 2011, 187, 1378–1392. [Google Scholar] [CrossRef] [Green Version]
- Revil, A.; Jardani, A.; Sava, P.; Haas, A. The Seismoelectric Method: Theory and Applications; Wiley-Blackwell: Hoboken, NJ, USA, 2015. [Google Scholar]
- Russell, R.D.; Butler, K.E.; Kepic, A.W.; Maxwell, M. Seismoelectric exploration. Lead. Edge 2017, 16, 1611. [Google Scholar] [CrossRef]
- Revil, A. Transport of water and ions in partially water-saturated porous media. Part 1. Constitutive equations. Adv. Water Resour. 2017, 103, 119–138. [Google Scholar] [CrossRef]
- Munoz-Carpena, R. Field Devices For Monitoring Soil Water Content. In BUL343; Agricultural and Biological Engineering Department, UF/IFAS Extension, University of Florida: Gainesville, FL, USA, 2004. [Google Scholar]
- He, H.; Dyck, M.F.; Horton, R.; Ren, T.; Bristow, K.L.; Lv, J.; Si, B. Development and Application of the Heat Pulse Method for Soil Physical Measurements. Rev. Geophys. 2018, 56, 567–620. [Google Scholar] [CrossRef]
- Dias, P.C.; Cadavid, D.; Ortega, S.; Ruiz, A.; França, M.B.M.; Morais, F.J.O.; Ferreira, E.C.; Cabot, A. Autonomous soil moisture sensor based on nanostructured thermosensitive resistors powered by an integrated thermoelectric generator. Sens. Actuators A Phys. 2016, 239, 1–7. [Google Scholar] [CrossRef]
- Jorapur, N.; Palaparthy, V.S.; Sarik, S.; John, J.; Baghini, M.S.; Ananthasuresh, G.K. A low-power, low-cost soil-moisture sensor using dual-probe heat-pulse technique. Sens. Actuators A Phys. 2015, 233, 108–117. [Google Scholar] [CrossRef]
- Dias, P.C.; Roque, W.; Ferreira, E.C.; Siqueira Dias, J.A. Proposal of a novel heat dissipation soil moisture sensor. In Proceedings of the Recent Researches in Circuits, Systems and Signal Processing—Proceeding of the 5th WSEAS International Conference on Circuits, Corfu, Greece, 14–16 July 2011; pp. 124–127. [Google Scholar]
- Dias, P.C.; Roque, W.; Ferreira, E.C.; Siqueira Dias, J.A. A high sensitivity single-probe heat pulse soil moisture sensor based on a single npn junction transistor. Comput. Electron. Agric. 2013, 96, 139–147. [Google Scholar] [CrossRef]
- Valente, A.; Saraiva, A.A.; Fonseca Ferreira, N.M.; Soares, S. On the design and construction of dual-probe heat-pulse soil moisture sensor: Towards an industrial solution. In Proceedings of the Allsensors 2018: The Third International Conference on Advances in Sensors, Actuators, Metering and Sensing, Rome, Italy, 25–29 March 2018. [Google Scholar]
- Dong, J.; Agliata, R.; Steele-Dunne, S.; Hoes, O.; Bogaard, T.; Greco, R.; van de Giesen, N. The impacts of heating strategy on soil moisture estimation using actively heated fiber optics. Sensors 2017, 17, 2102. [Google Scholar] [CrossRef] [Green Version]
- Ciocca, F.; Lunati, I.; van de Giesen, N.; Parlange, M.B. Heated optical fiber for distributed soil-moisture measurements: A lysimeter experiment. Vadose Zone J. 2012, 11. [Google Scholar] [CrossRef]
- Gil-Rodríguez, M.; Rodríguez-Sinobas, L.; Benítez-Buelga, J.; Sánchez-Calvo, R. Application of active heat pulse method with fiber optic temperature sensing for estimation of wetting bulbs and water distribution in drip emitters. Agric. Water Manag. 2013, 120, 72–78. [Google Scholar] [CrossRef] [Green Version]
- Selker, J.S.; Thévenaz, L.; Huwald, H.; Mallet, A.; Luxemburg, W.; Van De Giesen, N.; Stejskal, M.; Zeman, J.; Westhoff, M.; Parlange, M.B. Distributed fiber-optic temperature sensing for hydrologic systems. Water Resour. Res. 2006, 42. [Google Scholar] [CrossRef] [Green Version]
- Leone, M.; Principe, S.; Consales, M.; Parente, R.; Laudati, A.; Caliro, S.; Cutolo, A.; Cusano, A. Fiber optic thermo-hygrometers for soil moisture monitoring. Sensors 2017, 17, 1451. [Google Scholar] [CrossRef] [Green Version]
- Yeo, T.L.; Sun, T.; Grattan, K.T.V. Fibre-optic sensor technologies for humidity and moisture measurement. Sens. Actuators A Phys. 2008, 144, 280–295. [Google Scholar] [CrossRef]
- Cao, D.F.; Shi, B.; Zhu, H.H.; Tang, C.S.; Song, Z.P.; Wei, G.Q.; Garg, A. Characterization of soil moisture distribution and movement under the influence of watering-dewatering using AHFO and BOTDA technologies. Environ. Eng. Geosci. 2019, 25, 189–202. [Google Scholar] [CrossRef]
- Benítez-Buelga, J.; Sayde, C.; Rodríguez-Sinobas, L.; Selker, J.S. Heated fiber optic distributed temperature sensing: A dual-probe heat-pulse approach. Vadose Zone J. 2014, 13. [Google Scholar] [CrossRef] [Green Version]
- Vidana Gamage, D.N.; Biswas, A.; Strachan, I.B.; Adamchuk, V.I. Soil water measurement using actively heated fiber optics at field scale. Sensors 2018, 18, 1116. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Cao, D.F.; Shi, B.; Wei, G.Q.; Chen, S.E.; Zhu, H.H. An improved distributed sensing method for monitoring soil moisture profile using heated carbon fibers. Meas J. Int. Meas. Confed. 2018, 123, 175–184. [Google Scholar] [CrossRef]
- Cao, D.F.; Shi, B.; Zhu, H.H.; Inyang, H.I.; Wei, G.Q.; Duan, C.Z. A soil moisture estimation method using actively heated fiber Bragg grating sensors. Eng. Geol. 2018, 242, 142–149. [Google Scholar] [CrossRef]
- Vinda Gamage, D.N.; Biswas, A.; Strachan, I.B. Field water balance closure with actively heated fiber-optics and point-based soil water sensors. Water 2019, 11, 135. [Google Scholar] [CrossRef] [Green Version]
- Zubelzu, S.; Rodriguez-Sinobas, L.; Saa-Requejo, A.; Benitez, J.; Tarquis, A.M. Assessing soil water content variability through active heat distributed fiber optic temperature sensing. Agric. Water Manag. 2019, 212, 193–202. [Google Scholar] [CrossRef]
- Vidana Gamage, D.N.; Biswas, A.; Strachan, I.B. Actively heated fiber optics method to monitor three-dimensional wetting patterns under drip irrigation. Agric. Water Manag. 2018, 210, 243–251. [Google Scholar] [CrossRef]
- Ahmed, E.M. Hydrogel: Preparation, characterization, and applications: A review. J. Adv. Res. 2015, 6, 105–121. [Google Scholar] [CrossRef] [Green Version]
- Palade, D.D.; Darie, C.I. Soil moisture threshold sensor with electrical contact. Rom. Rev. Precis. Mech. Opt. Mechatron. 2015, 2015, 205–208. [Google Scholar]
- Romero, M.R.; Wolfel, A.; Igarzabal, C.I.A. Smart valve: Polymer actuator to moisture soil control. Sens. Actuators B Chem. 2016, 234, 53–62. [Google Scholar] [CrossRef]
- Chen, W.; Wu, G.; Zhang, M.; Greybush, N.J.; Howard-Jennings, J.P.; Song, N.; Stinner, F.S.; Yang, S.; Kagan, C.R. Angle-Independent Optical Moisture Sensors Based on Hydrogel-Coated Plasmonic Lattice Arrays. ACS Appl. Nano Mater. 2018, 1, 1430–1437. [Google Scholar] [CrossRef]
- Lee, S.; Seo, M.; Lee, M. Highly sensitive moisture sensor with a hydrogel film coated on surface-textured stainless steel. Appl. Surf. Sci. 2019, 484, 1149–1153. [Google Scholar] [CrossRef]
- McJannet, D.; Hawdon, A.; Baker, B.; Renzullo, L.; Searle, R. Multiscale soil moisture estimates using static and roving cosmic-ray soil moisture sensors. Hydrol. Earth Syst. Sci. 2017, 21, 6049–6067. [Google Scholar] [CrossRef] [Green Version]
- Zreda, M.; Desilets, D.; Ferré, T.P.A.; Scott, R.L. Measuring soil moisture content non-invasively at intermediate spatial scale using cosmic-ray neutrons. Geophys. Res. Lett. 2008, 35. [Google Scholar] [CrossRef] [Green Version]
- Pathak, H.S.; Brown, P.; Best, T. A systematic literature review of the factors affecting the precision agriculture adoption process. Precis. Agric. 2019, 20, 1292–1316. [Google Scholar] [CrossRef]
- Bhakta, I.; Phadikar, S.; Majumder, K. State-of-the-art technologies in precision agriculture: A systematic review. J. Sci. Food Agric. 2019, 99, 4878–4888. [Google Scholar] [CrossRef]
- Dimitrova-Petrova, K.; Geris, J.; Wilkinson, M.E.; Rosolem, R.; Verrot, L.; Lilly, A.; Soulsby, C. Opportunities and challenges in using catchment-scale storage estimates from cosmic ray neutron sensors for rainfall-runoff modelling. J. Hydrol. 2020, 586. [Google Scholar] [CrossRef]
- Tan, X.; Zhang, L.; He, C.; Zhu, Y.; Han, Z.; Li, X. Applicability of cosmic-ray neutron sensor for measuring soil moisture at the agricultural-pastoral ecotone in northwest China. Sci. China Earth Sci. 2020, 63, 1730–1744. [Google Scholar] [CrossRef]
- Martini, E.; Werban, U.; Zacharias, S.; Pohle, M.; Dietrich, P.; Wollschläger, U. Repeated electromagnetic induction measurements for mapping soil moisture at the field scale: Validation with data from a wireless soil moisture monitoring network. Hydrol. Earth Syst. Sci. 2017, 21, 495–513. [Google Scholar] [CrossRef] [Green Version]
- Altdorff, D.; Galagedara, L.; Nadeem, M.; Cheema, M.; Unc, A. Effect of agronomic treatments on the accuracy of soil moisture mapping by electromagnetic induction. Catena 2018, 164, 96–106. [Google Scholar] [CrossRef]
- Rodrigues, F.A.; Bramley, R.G.V.; Gobbett, D.L. Proximal soil sensing for Precision Agriculture: Simultaneous use of electromagnetic induction and gamma radiometrics in contrasting soils. Geoderma 2015, 243–244, 183–195. [Google Scholar] [CrossRef]
- Doolittle, J.A.; Sudduth, K.A.; Kitchen, N.R.; Indorante, S.J. Estimating depths to claypans using electromagnetic induction methods. J. Soil Water Conserv. 1994, 49, 572–575. [Google Scholar]
- Inman, D.J.; Freeland, R.S.; Ammons, J.T.; Yoder, R.E. Soil investigations using electromagnetic induction and ground-penetrating radar in Southwest Tennessee. Soil Sci. Soc. Am. J. 2002, 66, 206–211. [Google Scholar] [CrossRef] [Green Version]
- Stanley, J.N.; Lamb, D.W.; Falzon, G.; Schneider, D.A. Apparent electrical conductivity (ECa) as a surrogate for neutron probe counts to measure soil moisture content in heavy clay soils (Vertosols). Soil Res. 2014, 52, 373–378. [Google Scholar] [CrossRef]
- Calamita, G.; Perrone, A.; Brocca, L.; Onorati, B.; Manfreda, S. Field test of a multi-frequency electromagnetic induction sensor for soil moisture monitoring in southern Italy test sites. J. Hydrol. 2015, 529, 316–329. [Google Scholar] [CrossRef]
- Badewa, E.; Unc, A.; Cheema, M.; Kavanagh, V.; Galagedara, L. Soil moisture mapping using multi-frequency and multi-coil electromagnetic induction sensors on managed podzols. Agronomy 2018, 8, 224. [Google Scholar] [CrossRef] [Green Version]
- Shanahan, P.W.; Binley, A.; Whalley, W.R.; Watts, C.W. The use of electromagnetic induction to monitor changes in soil moisture profiles beneath different wheat genotypes. Soil Sci. Soc. Am. J. 2015, 79, 459–466. [Google Scholar] [CrossRef] [Green Version]
- Moghadas, D.; André, F.; Slob, E.C.; Vereecken, H.; Lambot, S. Joint full-waveform analysis of off-ground zero-offset ground penetrating radar and electromagnetic induction synthetic data for estimating soil electrical properties. Geophys. J. Int. 2010, 182, 1267–1278. [Google Scholar] [CrossRef] [Green Version]
- Lu, C.; Zhou, Z.; Zhu, Q.; Lai, X.; Liao, K. Using residual analysis in electromagnetic induction data interpretation to improve the prediction of soil properties. Catena 2017, 149, 176–184. [Google Scholar] [CrossRef]
- Wang, H.; Wellmann, F.; Zhang, T.; Schaaf, A.; Kanig, R.M.; Verweij, E.; von Hebel, C.; van der Kruk, J. Pattern Extraction of Topsoil and Subsoil Heterogeneity and Soil-Crop Interaction Using Unsupervised Bayesian Machine Learning: An Application to Satellite-Derived NDVI Time Series and Electromagnetic Induction Measurements. J. Geophys. Res. Biogeosci. 2019, 124, 1524–1544. [Google Scholar] [CrossRef]
- Huang, J.; Scudiero, E.; Choo, H.; Corwin, D.L.; Triantafilis, J. Mapping soil moisture across an irrigated field using electromagnetic conductivity imaging. Agric. Water Manag. 2016, 163, 285–294. [Google Scholar] [CrossRef]
- Moghadas, D.; Jadoon, K.Z.; McCabe, M.F. Spatiotemporal monitoring of soil water content profiles in an irrigated field using probabilistic inversion of time-lapse EMI data. Adv. Water Resour. 2017, 110, 238–248. [Google Scholar] [CrossRef] [Green Version]
- Van Der Kruk, J.; Von Hebel, C.; Brogi, C.; Kaufmann, M.S.; Tan, X.; Weihermüller, L.; Mester, A.; Huisman, J.A.; Vereecken, H. Calibration, inversion and applications of multi-configuration EMI for agricultural top- and subsoil characterization. In Proceedings of the 2018 SEG International Exposition and Annual Meeting, SEG 2018, Anaheim, CA, USA, 14–19 October 2018; pp. 2546–2550. [Google Scholar]
- Samouëlian, A.; Cousin, I.; Tabbagh, A.; Bruand, A.; Richard, G. Electrical resistivity survey in soil science: A review. Soil Tillage Res. 2005, 83, 173–193. [Google Scholar] [CrossRef] [Green Version]
- Sudduth, K.A.; Drummond, S.T.; Kitchen, N.R. Accuracy issues in electromagnetic induction sensing of soil electrical conductivity for precision agriculture. Comput. Electron. Agric. 2001, 31, 239–264. [Google Scholar] [CrossRef]
- Zhu, Q.; Lin, H.; Doolittle, J. Repeated electromagnetic induction surveys for determining subsurface hydrologic dynamics in an agricultural landscape. Soil Sci. Soc. Am. J. 2010, 74, 1750–1762. [Google Scholar] [CrossRef] [Green Version]
- Bellon-Maurel, V.; McBratney, A. Near-infrared (NIR) and mid-infrared (MIR) spectroscopic techniques for assessing the amount of carbon stock in soils—Critical review and research perspectives. Soil Biol. Biochem. 2011, 43, 1398–1410. [Google Scholar] [CrossRef]
- Pallottino, F.; Antonucci, F.; Costa, C.; Bisaglia, C.; Figorilli, S.; Menesatti, P. Optoelectronic proximal sensing vehicle-mounted technologies in precision agriculture: A review. Comput. Electron. Agric. 2019, 162, 859–873. [Google Scholar] [CrossRef]
- Soriano-Disla, J.M.; Janik, L.J.; Viscarra Rossel, R.A.; MacDonald, L.M.; McLaughlin, M.J. The performance of visible, near-, and mid-infrared reflectance spectroscopy for prediction of soil physical, chemical, and biological properties. Appl. Spectrosc. Rev. 2014, 49, 139–186. [Google Scholar] [CrossRef]
- Stenberg, B.; Viscarra Rossel, R.A.; Mouazen, A.M.; Wetterlind, J. Visible and Near Infrared Spectroscopy in Soil Science. In Advances in Agronomy; Academic Press: Cambridge, MA, USA, 2010; Volume 107, pp. 163–215. [Google Scholar]
- Marakkala Manage, L.P.; Humlekrog Greve, M.; Knadel, M.; Moldrup, P.; De Jonge, L.W.; Katuwal, S. Visible-near-infrared spectroscopy prediction of soil characteristics as affected by soil-water content. Soil Sci. Soc. Am. J. 2018, 82, 1333–1346. [Google Scholar] [CrossRef]
- Yin, Z.; Lei, T.; Yan, Q.; Chen, Z.; Dong, Y. A near-infrared reflectance sensor for soil surface moisture measurement. Comput. Electron. Agric. 2013, 99, 101–107. [Google Scholar] [CrossRef]
- Liang, X.; Li, X.; Lei, T. A new NIR technique for rapid determination of soil moisture content. In Proceedings of the 2012 International Conference on Systems and Informatics, ICSAI 2012, Yantai, China, 19–20 May 2012; pp. 16–20. [Google Scholar]
- Liang, X.Y.; Li, X.Y.; Lei, T.W. The rapid detection of undisturbed soil moisture content based on BPNN. In Proceedings of the 2010 6th International Conference on Natural Computation, ICNC 2010, Yantai, China, 19–20 May 2012; pp. 1910–1913. [Google Scholar]
- Mouazen, A.M.; Maleki, M.R.; Cockx, L.; Van Meirvenne, M.; Van Holm, L.H.J.; Merckx, R.; De Baerdemaeker, J.; Ramon, H. Optimum three-point linkage set up for improving the quality of soil spectra and the accuracy of soil phosphorus measured using an on-line visible and near infrared sensor. Soil Tillage Res. 2009, 103, 144–152. [Google Scholar] [CrossRef] [Green Version]
- Tekin, Y.; Kuang, B.; Mouazen, A.M. Potential of on-line visible and near infrared spectroscopy for measurement of pH for deriving variable rate lime recommendations. Sensors 2013, 13, 10177–10190. [Google Scholar] [CrossRef] [PubMed]
- Rodionov, A.; Welp, G.; Damerow, L.; Berg, T.; Amelung, W.; Pätzold, S. Towards on-the-go field assessment of soil organic carbon using Vis-NIR diffuse reflectance spectroscopy: Developing and testing a novel tractor-driven measuring chamber. Soil Tillage Res. 2015, 145, 93–102. [Google Scholar] [CrossRef]
- Lambot, S.; Slob, E.; Minet, J.; Jadoon, K.Z.; Vanclooster, M.; Vereecken, H. Full-Waveform Modelling and Inversion of Ground-Penetrating Radar Data for Non-invasive Characterisation of Soil Hydrogeophysical Properties. In Proximal Soil Sensing; Viscarra Rossel, R.A., McBratney, A.B., Minasny, B., Eds.; Springer: Dordrecht, The Netherlands, 2010; pp. 299–311. [Google Scholar] [CrossRef]
- Vereecken, H.; Huisman, J.A.; Pachepsky, Y.; Montzka, C.; van der Kruk, J.; Bogena, H.; Weihermüller, L.; Herbst, M.; Martinez, G.; Vanderborght, J. On the spatio-temporal dynamics of soil moisture at the field scale. J. Hydrol. 2014, 516, 76–96. [Google Scholar] [CrossRef]
- Zhang, L.; Lu, T.; Yu, P.; Zhang, C. Parameter measurement of soil moisture based on GNSS-R signals. In Proceedings of the 2019 IEEE International Conference on Artificial Intelligence and Computer Applications, ICAICA 2019, Dalian, China, 29–31 March 2019; pp. 161–166. [Google Scholar]
- Zhang, S.; Calvet, J.C.; Darrozes, J.; Roussel, N.; Frappart, F.; Bouhours, G. Deriving surface soil moisture from reflected GNSS signal observations from a grassland site in southwestern France. Hydrol. Earth Syst. Sci. 2018, 22, 1931–1946. [Google Scholar] [CrossRef] [Green Version]
- Toy, C.W.; Steelman, C.M.; Endres, A.L. Comparing electromagnetic induction and ground penetrating radar techniques for estimating soil moisture content. In Proceedings of the 13th Internarional Conference on Ground Penetrating Radar, GPR 2010, Lecce, Italy, 21–25 June 2010. [Google Scholar]
- Shamir, O.; Goldshleger, N.; Basson, U.; Reshef, M. Mapping spatial moisture content of unsaturated agricultural soils with ground-penetrating radar. In Proceedings of the International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences—ISPRS Archives, Prague, Czech Republic, 2–19 July 2016; pp. 1279–1285. [Google Scholar]
- Liu, X.; Cui, X.; Guo, L.; Chen, J.; Li, W.; Yang, D.; Cao, X.; Chen, X.; Liu, Q.; Lin, H. Non-invasive estimation of root zone soil moisture from coarse root reflections in ground-penetrating radar images. Plant Soil 2019, 436, 623–639. [Google Scholar] [CrossRef]
- Klotzsche, A.; Jonard, F.; Looms, M.C.; van der Kruk, J.; Huisman, J.A. Measuring soil water content with ground penetrating radar: A decade of progress. Vadose Zone J. 2018, 17. [Google Scholar] [CrossRef] [Green Version]
- Chang, X.; Jin, T.; Yu, K.; Li, Y.; Li, J.; Zhang, Q. Soil moisture estimation by GNSS multipath signal. Remote Sens. 2019, 11, 2559. [Google Scholar] [CrossRef] [Green Version]
- Bogena, H.R.; Huisman, J.A.; Vereecken, H. Emerging methods for noninvasive sensing of soil moisture dynamics from field to catchment scale. In Proceedings of the AGU Fall Meeting Abstracts, San Francisco, CA, USA, 14–18 December 2015. [Google Scholar]
- Koch, F.; Schlenz, F.; Prasch, M.; Appel, F.; Ruf, T.; Mauser, W. Soil moisture retrieval based on GPS signal strength attenuation. Water 2016, 8, 276. [Google Scholar] [CrossRef]
- Han, M.; Zhu, Y.; Yang, D.; Hong, X.; Song, S. A semi-empirical SNR model for soil moisture retrieval using GNSS SNR data. Remote Sens. 2018, 10, 280. [Google Scholar] [CrossRef] [Green Version]
- Steinberg, M.D.; Tkalčec, B.; Steinberg, I.M. Towards a passive contactless sensor for monitoring resistivity in porous materials. Sens. Actuators B Chem. 2016, 234, 294–299. [Google Scholar] [CrossRef]
- Zajícová, K.; Chuman, T. Application of ground penetrating radar methods in soil studies: A review. Geoderma 2019, 343, 116–129. [Google Scholar] [CrossRef]
- Meisami-Asl, E.; Sharifi, A.; Mobli, H.; Eyvani, A.; Alimardani, R. On-site measurement of soil moisture content using an acoustic system. Agric. Eng. Int. CIGR J. 2013, 15, 1–8. [Google Scholar]
Accuracy & reliability | Installation | Measurement scale | Development stage | Suitable soil / Agriculture | Cost | Key Limitations | Key Advantages | Research Needs | Reference | |
---|---|---|---|---|---|---|---|---|---|---|
Cosmic Ray | High | NI | Very large | Commercialised | All | High | Variable measurement area and depth | Large measurement scale | Calibration algorithms | [1] |
Downhole TDR | High | D | Small | Commercialised | Non stony, non highly vertic soils | Moderate | Requires access hole | Larger measured volume and less affected by soil contact than FDR | Evaluation of usability | [36,38] |
Low cost FDR | Poor, variable | I | Very small | Prototype to Commercialised | Non stony, non vertic, non saline soils. Shallow rooted crops | Low | Soil-sensor contact, salinity, temperature | Low cost, mass production | Evaluation of performance | [41,42,49] |
RFID | Moderate (unknown) | NI, OG | Surface only, small area | Prototype / Conceptual | Most soils (unknown) Nurseries, glasshouse, very shallow rooted crops | Very low | Shallow depth, requires active reader | Very low cost | Identify suitable applications, simplify readings | [50,52,53,160] |
GPS-IR & GNSS-IR | Moderate, (unknown) | NI, OG, M | Surface only, large area | Early prototype | Most (unknown). Shallow rooted crops | Low | Shallow depth of measurement, soil roughness | Available everywhere, intermediate scale, can be stationary or mobilised | Signal analysis | [150,156,158,160] |
GPR | Moderate to high | NI, M, OG | Medium & depth-wise | Advanced | Most soils except saline and some clays | Moderate - high | Expertise required for analysis | Mobile, extend to several metres depth | Algorithms for improved estimation of soil moisture | [153,154,161] |
Paired radio / acoustic / seismic waves | Unknown, (soil specific) | I, D | Unknown, medium | Early Prototype / Conceptual | Unknown, less successful in saline, compacted soils | Low - moderate | Unknown effect of soil properties on signal attenuation | Medium scale of measurement Completely buried | Improved theoretical understanding of wave propagation in soil, multi-wave analysis of soil properties and soil moisture. | [61,70,76,162] |
Seismoelectric | Unknown | NI | Medium - large | Early | Unknown | Unknown | Limited understanding of streaming current behavior in soils | Ability to simultaneously measure, porosity, hydraulic conductivity and moisture content in 2D sections | Downscaling, theoretical understanding, application, evaluation in agricultural soils | [77,79,82,84,85] |
EMI | Variable | NI, M OG | Medium | Commercialised | Most non saline, non ferric soils | Moderate | Bulked signal, need for local calibration | Mobile, affordable, moderate operation and data analysis skills | Machine learning based analysis | [119,125,126] |
Nir VIS, NIR, MIR | High | OG | surface | Commercialised | All | High | Shallow depth of penetration. Sample preparation | Quick, relatively straight forward, non invasive | Robustness or below ground applications | [142,143,147] |
Heat Pulse | High | I | Small | Commercialised | Most, preferably non stony and non vertic | Moderate | Power usage, costly electronics | More accurate and larger measurement area than FDR. Not influenced by salinity | Lower production cost | [89,92] |
Thermo-Optical Fiber DTS | High | I, D | 1–5 cm × 1000 m | Prototype | Non vertic soils, drip irrigation, perennial tree crops | Unknown | Fragility of the optic fiber, requires good soil contact | Distributed approach with mm accuracy positioning | Sensor robustness, evaluation in agricultural soils | [96,106] |
HCT | High | I | 1–5 cm | Prototype | Non vertic, and non saline | Unknown | Complicated de-airing | Measurement range 0 to −1500 kPa | Simplified deairing and filling apparatus, new design concepts. | [22,23,147] |
Hydrogels | Unknown | I, D | 1–5 cm | Prototype / conceptual | Non vertic and potentially non saline soils | Unknown | Soil – sensor contact, effects of pH, and gel lifespan | Potentially low cost, larger measurement range than tensiometers | Field evaluation, new compounds, application design | [110,111,112] |
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Hardie, M. Review of Novel and Emerging Proximal Soil Moisture Sensors for Use in Agriculture. Sensors 2020, 20, 6934. https://doi.org/10.3390/s20236934
Hardie M. Review of Novel and Emerging Proximal Soil Moisture Sensors for Use in Agriculture. Sensors. 2020; 20(23):6934. https://doi.org/10.3390/s20236934
Chicago/Turabian StyleHardie, Marcus. 2020. "Review of Novel and Emerging Proximal Soil Moisture Sensors for Use in Agriculture" Sensors 20, no. 23: 6934. https://doi.org/10.3390/s20236934