66 Soil structure is the natural arrangement of the soil into separate aggregates. Tillage tends to destroy soil structure. The size and number of aggregates are affected by tillage.
Organic matter is lost during and after tillage.
Bulk density, soil porosity, aeration, and water movement problems are aggravated by tillage. Soil aggregates, or clods, are destroyed by tillage -both by the physical disruption caused by the implement and by the compression forces of the tractor and implement wheels. Clod size is very important in considering wind resistance. Naturally, the larger the clods, the better the resistance to erosion. It is well known that microorganisms play a key role in maintaining soil structure.