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Gardeners and farmers improve the quality of their soil by adding compost or manure. Compost is made from dead plants and manure is the waste from animals. Once spread on the soil, compost and manure are broken down into minerals by decomposing bacteria and fungi, as well as by other organisms, such as worms. Adding compost or manure helps recycle minerals so that they are absorbed by new plants and used in growth. Compost and manure also improve the quality of soil by increasing aeration and water retention.

Farmers can also use inorganic fertilisers on soil to overcome specific mineral deficiencies, although this does not require the involvement of decomposers.

One key element which is recycled is nitrogen. This element is needed by plants to make proteins to grow and repair themselves. Plants cannot absorb nitrogen gas, and need it to be provided as nitrate ions. These nitrate ions are produced as a result of a long series of reactions by bacterial decomposers breaking down proteins and urea in the soil. The nutrients and minerals are then passed along the food chain as the organisms are consumed by others.