Review of Novel and Emerging Proximal Soil Moisture Sensors for Use in Agriculture.

Marcus Hardie

doi:10.3390/s20236934

Abstract

The measurement of soil moisture in agriculture is currently dominated by a small number of sensors, the use of which is greatly limited by their small sampling volume, high cost, need for close soil–sensor contact, and poor performance in saline, vertic and stony soils. This review was undertaken to explore the plethora of novel and emerging soil moisture sensors, and evaluate their potential use in agriculture. The review found that improvements to existing techniques over the last two decades are limited, and largely restricted to frequency domain reflectometry approaches. However, a broad range of new, novel and emerging means of measuring soil moisture were identified including, actively heated fiber optics (AHFO), high capacity tensiometers, paired acoustic / radio / seismic transceiver approaches, microwave-based approaches, radio frequency identification (RFID), hydrogels and seismoelectric approaches. Excitement over this range of potential new technologies is however tempered by the observation that most of these technologies are at early stages of development, and that few of these techniques have been adequately evaluated in situ agricultural soils.

Highlights

Knowledge of soil moisture is important for supporting agricultural production, catchment hydrology, flood forecasting, landslide prediction and other ecosystem services [1,2,3]
Use of existing soil moisture sensors requires a high degree of confidence that the sensor is correctly installed, that it is located in a representative soil type, that soil types are more or less uniform over an entire block, center pivot circle or management unit
Farmers have never had the technology that they want to be using for measuring soil moisture

Summary

Introduction

Knowledge of soil moisture is important for supporting agricultural production, catchment hydrology, flood forecasting, landslide prediction and other ecosystem services [1,2,3]. Global demand for diminishing water resources has triggered renewed interest in the development of proximal soil moisture sensors for improved management of irrigation and soil moisture in agriculture. Proximal soil sensors are defined as being in contact with, or within proximity to the soil (

Methods

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Discussion

Conclusion