What is Soil Structure?
Soil structure is the aggregation of soil particles (sand, silt, clay and organic matter) into granules, crumbs or blocks. It is the shape that the soil takes based on its physical, chemical and biological properties; it is very important since (along with texture) it affects drainage and aeration capacity of the soil.
Without structure a soil collapses and compacts, resulting in a number of problems for landscaping and civil projects. It can be considered as the "framework" of a Soil Profile.
Why is Structure Important?
Virtually all soils need an open structure through the soil profile in order to function effectively as a growing medium. In particular, soil structure influences the main soil and plant root functions, aeration, drainage and root development.
Without structure, soils will suffer from anaerobism, waterlogging and nutrient lock-up and, ultimately, plants will die!