Non-invasive acoustic-seismic sensing of soils

The lack of suitable methods to measure soil physical characteristics directly that are relevant to crop growth and soil environmental function (e.g. absorption of high intensity rainfall) are barriers to the development of approaches for sustainable soil management. The acoustical properties of air-filled porous media, such as soil, have been studied widely in various contexts. Models for these properties incorporate parameters related to the frame elasticity and the pore structure.
Objectives
1. To extend the theory and develop the algorithms required to conjunctively interpret data for acoustic reflection from soil and acoustic-to-seismic coupling in terms of internal stresses in soil, thus enabling (a) detection of hardpans (b) quantification of the amount of moisture and (c) deduction of the extent of connected macro-porosity in soil.
2. To validate the algorithms through well-defined laboratory experiments on model poroelastic systems and on real soils under laboratory conditions.
3. To validate the algorithms under field conditions in previously well-characterised sites and to develop the capability to sense how well soils function as environments for root elongation in situ and without disturbance.