Most soil organic matter starts out as plant material, but what happens after its deposition in soil changes its properties and makes it unique. Increased soil organic matter generally improves soil structure and increases soil fertility. How we manage a soil can change the organic matter content and distribution in a soil, and possibly even, over the short-term, make a soil less attractive for plant growth. Soil organic matter is a very complicated issue and one which we need to understand to make wise management decisions, in such areas as fertilizer management, selection of crops, and tillage practices.