Greens accumulate organic matter. Organic Matter is old leaf blades, dying roots, pollen etc. This organic matter clogs the pore space in the sand underneath the turf. When too much organic matter accumulates, the greens become soft and "thatchy." We aerify greens to remove some of this material and back fill the holes with fresh, clean sand. Topdressing is done every 2-3 weeks to "dilute" the organic matter. It helps firm the surface, it increases ball roll and helps level the surface.
Without a solid topdressing and aerification program in place, a USGA spec green would eventually die due to drainage failure. In fact, experts claim a USGA green has a life expectancy of 20-25 years. However, if a golf green is maintained properly and aggressively, it can last as long as the Club desires. Regrassing to a better turf variety is usually the reason Clubs will pull the trigger on rebuilding golf greens.
A lot of Superintendents are under pressure from memberships to reduce aerification procedures in order to push more rounds and revenue. For the short term, this may be effective but in the long run, this mentality will cost in a big way.
