Researching structural complexity in agricultural soils

Soil structure in the broadest sense can be described as the spatial arrangement of both soil particles and voids. From the level of clay particles and clay–organic matter complexes to the spatial arrangement of peds and clods in the soil profile, the scale of soil structure can range over several orders of magnitude. Due to the various levels of complexity, processes associated with primary structural components are often expressed at a higher level of structure, and thus secondary and tertiary levels of structure can be viewed as emergent soil ecosystem properties. At each level, soil structure directly and indirectly impacts on soil–air–water relations and processes. In turn, such processes are modified by soil and plant management, especially tillage practices. The latter influences nearly all levels of soil structural complexity. Research is ongoing to provide an improved understanding of soil structure and structure mediated processes and to develop or modify appropriate soil structure methodology. This volume presents a number of papers addressing different facets of soil structure research and methodology to help advance this area of science in agricultural soils.