'Mulch' refers to dry-process breakdown of plant tissues used as a soil ammendment and topping. The process is of manifold importance for the stewardship of a plot of land, as it provides a way to recycle the nutrient base of the biomass by metabolizing leaves, branches, roots and bark. The action of stearothermophiliibacteria drive the breakdown, both through direct decompositional feeding and through the oxidative heating their activity causes. Mulches are generally used in a semi-composted state for topping as a water retention and weed discouragement, although overuse in this manner can be harmful. As a proper amendment mulch is as diverse as the materials used to make it, aiding hydrolic stability, erosion control, nutrients and Ph balance. The practice of planting cover crops to serve the purposes of mulch is referred to as living mulch.
--B0b 11:51, 15 November 2007 (UTC)