Advances in Proximal Sensing of Soil Condition.

Our planet is facing pressing problems with a growing human population that need feeding, watering, clothing and sheltering. Soils, as a result, are under immense pressure to provide more and more. The economics bear this out, soil systems are one of Earth’s most valuable commodities, as they underpin global production of agricultural products, which in 2012 was worth nearly $3816 billion (U.S. dollars) according to FAOSTAT. This pressure to perform means our soils are changing, or being changed, at a rapid pace, by human activity in the form of production, land use change, climate change and pollution. In order to maintain the function of soil resources we need to both understand how they work, and the impact we are having on the natural capital soil stocks.

Destructive sampling of soils to measure state and change is expensive and time consuming. Therefore, the development of field based sensing tools to assess soil condition is of substantial interest. This is the realm of proximal sensing, that includes a suite of soil and geophysical sensors including TDR, GPR, EMI, IR etc, used to determine a range of soil properties insitu. Moreover, research includes all the associated disciplines required to sample, collect and transmit data, synthesise and fuse it, and ultimately communicate it. Advances in this field help us to observe and understand soil condition and behaviour insitu. They are our modern day observing systems like ships or telescopes used to explore the oceans or space. This talk provides an overview of proximal sensing and identifies some of the technical and scientific challenges we face going forward.