Healthy soils are important to healty turf growth. So many times we look at the Turf and forget that what makes it really great is the soil it grows in. Spreading a good quality compost on turf helps improve the microbiology of the soil by helping to generate a climate where beneficial micro-organisms can thrive. These microbes work really well in soils because as they break down they create a sticky material that glues the fine soil particles together. This causes the soil texture to granulate, or become crumblike. Such soil texture improves porosity in hevy soils and helps hold moisture and nutrients in sandy soils. Materials that decompose slowly, such as sphagnum peat moss, do not promote granulation.
To improve your turf try topdressing with compost spring and fall and aerate at least once a year.