Soil and Technology

Soil science constantly develops and applies new technologies for describing and assessing soils. Soil itself is a complex material and requires innovative and cutting edge technologies to unravel the complexities of interactions from the pore to landscape scales.

Current research at CEH includes work on hydrogeophysical imaging of soils at field and catchment scales in collaboration with other NERC researchers in the BGS Geoscience Technologies programme. This uses geophysical methods such as electromagnetic induction (EMI) and electrical resistivity to obtain electrical images of soil. These images can be 2D slices through the soil, or spatial maps of soil at the field scale. The electrical patterns are linked to soil properties such as moisture content and soil texture which can often be determined through calibration.

These methods are relatively non-invasive and provide an understanding of the spatial heterogeneity and structure of soils. They offer great potential for environmental research and precision agriculture.

The figure presented below shows an electrical image captured with EMI for a small upland catchment. The image is an overlay within the catchment boundaries. The red areas indicate high electrical conductivity clay soils and the blue areas are course textured soil with low electrical conductivity.

COSMOS is the COsmic-ray Soil Moisture Observing System, developed at the University of Arizona, USA. The instrument sensor is elevated above the ground and measures low-energy cosmic-ray neutrons above the ground, whose intensity is inversely correlated with soil water content, and with water in any form above ground level (e.g. vegetation).

The sensor measures integrated or average soil water content over a footprint of ~30 hectares, within a circle with a radius of ~300 m, integrating over a depth of ~50 cm.

COSMOS has the potential to fill an intermediate scale gap between point soil moisture sensors and soil moisture estimated using remote sensing technologies.