Maintaining soil fertility is an important step in creating a sustainable agriculture. Before stating how soil fertility is maintained, the causes of soil fertility decline must be stated. Farmers mine soil. In natural ecosystems soil minerals basically stay in place. Trees uptake minerals, pass the minerals to the leaves, and the leaves fall back to the earth where the process starts all over again.
Farmers remove the crops before the minerals can be replaced in the soil.
There are ways to lesson the mineral loss, but there is no way to stop it from happening completely. Minerals must be replaced from the outside. The first method to replenish minerals is through the application of fertilizers. There are two basic types of fertilizers organic and inorganic. Organic fertilizers are derived from organic matter, while inorganic fertilizers are generally mined and processed.