Organic fertilizers are fertilizers that are naturally produced and contain carbon (C). Fertilizers are materials that can be added to soil or plants, in order to provide nutrients and sustain growth. Typical organic fertilizers include mineral sources, all animal waste including meat processing, manure, slurry, and guano, plant based fertilizers, such as compost, and biosolids. There are also other abiotic non-chemical, fertilizer methods that meet the Principles of Organic Agriculture, which determines whether a fertilizer can be used for commercial organic agriculture.