This paper reviews various sensing technologies for monitoring soil moisture and nutrients in agriculture, ranging from laboratory methods to in-situ, remote, and proximal sensing. It covers the working principles of each method and discusses recent advancements and challenges, highlighting the trend towards low-cost, field-deployable systems for precision agriculture.

The authors acknowledge funding from the National Science Foundation, but no other potential conflicts are apparent.

This comprehensive review provides a valuable overview of various soil sensing technologies, covering different scales and approaches. The discussion of principles and recent advancements is well-structured, though the lack of a comparative cost analysis and detailed future directions slightly limit its impact. Overall, it's a valuable resource for anyone interested in agricultural sensing.