For Soil Application
As fresh organic matter decomposes, the nutrients it contains are released in inorganic form for use by plants. A portion of the nutrients is utilized by the soil microorganisms, but when they die and decompose the nutrients are again released. Organic matter, therefore, is an important source of nutrients for growing plants, especially those which would otherwise be leached from the soil. Decomposing organic matter supplies most of the nitrogen and sulfur, about half of the phosphorus, and appreciable amounts of the other plant nutrients.
As organic matter decomposes, it becomes chemically altered. This change gives it a negative electrical charge that attracts and holds inorganic elements such as potassium, calcium, magnesium, and several of micronutrients in forms that make them readily available to growing plants. Organic matter increases the moisture holding capacity of soil because organic particles absorb water like a sponge. In short, organic matter improves nutrient supplying power of the soil, soil structure, and moisture holding capacity.