Whether a compost pile is quick and hot or slow and cool, when the decomposers have completed their work the contents of the pile have been transformed to an entirely new material. The volume of the finished compost has been reduced because of biochemical breakdown and water respiration to about 30 to 50 percent of what went into the pile. This finished product offers numerous benefits to our garden soil. Compost will improve the quality of almost any soil, and for this reason it is most often considered a soil conditioner. Compost improves the structure and texture of the soil enabling it to better retain nutrients, moisture, and air for the betterment of plants.