They partly compensate for bonds that are broken by tillage. But, when soil drying occurs, as an added effect of tillage, the bonding effect of the microorganisms is lost. This indirectly decreases the stability of aggregates. The type of tillage equipment is also an important factor. The effect of cultivation on deterioration of soil structure is well documented.
Studies show decreases in aggregate stability, nitrogen and carbon contents.
Even if a significant percentage of clods in the soil is below optimal to resist wind erosion, the presence of vegetative cover, previous crop residue, and trash will protect soil from erosion. Residues will absorb the force of the wind, raising the threshold velocity necessary for wind erosion. The two primary conditions required to provide control from erosion are the presence of vegetative residue cover and optimal cloddiness. Only small grains eave sufficient residues after summer fallow to control wind erosion in much of eastern Montana. Short stubble partially worked into summer fallow is less effective in controlling wind erosion than standing stubble.