Organic or Natural fertilizers are fertilizers derived from animal matter, animal excreta (manure), human excreta, and vegetable matter (e.g. compost and crop residues). Naturally occurring organic fertilizers include animal wastes from meat processing, peat, manure, slurry, and guano.
In contrast, the majority of fertilizers used in commercial farming are extracted from minerals or produced industrially. Organic agriculture, a system of farming, allows for certain fertilizers and amendments and disallows others; that is also distinct from this topic.
The main organic fertilizers are peat, animal wastes (often from slaughterhouses), plant wastes from agriculture, and treated sewage sludge. By many definitions, minerals are separate from organic materials. However, certain organic fertilizers and amendments are mined, specifically, guano and peat, and other mined minerals are fossil products of animal activity, such as greensand (anaerobic marine deposits), some.
limestones (fossil shell deposits) and some rock phosphates, (fossil guano). Peat, a precursor to coal, offers no nutritional value to the plants, but improves the soil by aeration and absorbing water; it is sometimes credited as being the most widely use organic fertilizer and by volume is the top organic amendment.
Chicken litter, which consists of chicken manure mixed with sawdust, is an organic fertilizer that has been shown to better condition soil for harvest than synthesized fertilizer.
Processed organic fertilizers include compost, humic acid, amino acids, and seaweed extracts. Other examples are natural enzyme-digested proteins. Decomposing crop residue (green manure) from prior years is another source of fertility.
Treated sewage sludge
Although night soil (from human excreta) was a traditional organic fertilizer, the main source of this type is nowadays treated sewage sludge, also known as biosolids. Industrial pollutants in sewage sludge prevent recycling it as fertilizer.