The addition of organic matter via manure can have a sustained beneficial effect on the soil because it remains as a long term nutrient source for microbes and soil binding agents. The improvement in soil structure attributed to the added soil organic matter can reduce runoff and increase soil water storage and plant productivity.
In organic farming, particular types of grasses or legumes in pastoral applications cow manure and chicken manures are used to add nitrogen, carbon and other nutrients back into soil. “Feed the soil to feed the plant”, don’t just feed the plant. Since the 1950s, much of modern farming has become dependent on industrially manufactured fertilisers (not used in organic systems) to add nitrogen, phosphorous and potassium back into the soil.
The most important element for plant development is nitrogen in the soil. Nitrogen plays a major part in the development of chlorophyll and the associated green colour that plants have. It is responsible for lush, vigorous growth and the development of dense vegetation.
Nitrogen applied in the form of manure fosters favourable soil microbes, which are indicative of healthy, fertile soil. Manufactured fertilisers infuse the soil with more nitrogen than the plants can use and the excess is washed into rivers and streams.