Measurement of Soil Physical Properties in the Field

Abstract

Increasing efforts have been spent in the past two decades on field measurement of soil physical properties and on the development of transport models. Here a summary is given of the characteristics of field soils gleaned from such measurements. The principle feature of field soils is their variability over many length and time scales. Issues involved in measurements in a heterogeneous environment are considered. These include the interaction of measurement scale with perceived variability, soil-imposed weighting of measurements, the Heisenberg uncertainty principle, the use of correlations, inverse measurement techniques, and soil macrostructure and biological activity. Some criteria for field measurements are identified. Predictive frameworks for interpreting and using field data are discussed. These range from the fully deterministic to stochastic theories. The successes and limitations of these are considered. Finally, some remaining problem areas are identified.