One of the best things to do for just about all soils is to add things that keep it in good shape. These things are called soil conditioners and include manure, compost, peat moss, and leaves. All of the soil conditioners are put on top of the soil (about 2-3 inches deep) and then mixed into the soil.
This type of substance is added to improve the soil condition by means of enhancing the aeration and water holding capacity. Peat, crop residues, livestock manures are the common materials that are used in the production of soil conditioner.
For more information on soil conditioners, please click the following link:
http://urbanext.illinois.edu/firstgarden/basics/dirt_05.cfm