Infiltration relates to how fast water can enter the soil and move down though the soil profile. With good aggregation and residue cover water can infiltration can improve. Raindrops can fall as fast as 20 mph and have a devastating impact if hitting bare soil. This impact can move soil particles from 3 to 5 feet! With residue to intercept the force of raindrops and allow water to infiltrate, erosion is reduced and water can be used by the crop.