Recently, researchers at the University of Alabama developed an index called the Lawn and Garden Moisture Index or LGMI, which monitors the capacity of current soil moisture to sustain healthy lawns and gardens. This 4-page fact sheet explains the nuts and bolds of the LGMI and how to monitor and forecast the index on agroclimate.org. Written by Clyde W. Fraisse, Prem Woli, and Keith T. Ingram, and published by the UF Department of Agricultural and Biological Engineering, February 2011.
http://edis.ifas.ufl.edu/ae470