Key challenges faced with physics in soils

Abstract

Soil physics is a division of science that has dual identities, a branch of physics and a branch of soil science. The development of soil physics originated as an exercise in irrigation and drainage, essentially first to understanding how physical processes operate in a porous system. Soil physics draws on principles of physics, physical chemistry, and engineering and has resulted in additional sub-disciplines being developed. This branch of science has addressed practical problems faced in agriculture, ecology, engineering and other disciplines. A question that is often raised is whether education in physics or an education in soil science is more important for a soil physicists. Three key case studies will be explored to illustrate the importance of physics to soil science and the challenges currently faced. The first will be an examination of capillary theory for water flow in porous systems and limitations in soil systems. The second will be a discussion on why soil moisture sensors are not being adopted as common practice and how fibre optics and cosmic rays may bridge the gap. The final case study that will be examined are the issues faced with growing mediums and the debate we have in terms of waste material used in food production in soils.