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Revision as of 04:58, 12 June 2003 by Anthere (talk | contribs)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)Fertilizers are substances added to soil with the intention of promoting plant growth.
Fertilizers typically provide—in varying proportions—the 3 major plant nutrients (nitrogen, potassium and phosphorus), the 4 secondary plant nutrients (calcium, sulfur, magnesium, and sodium) and sometimes trace elements. Fertilizer can be created either from natural organic material such as manure or compost (see also organic gardening), or artificially as through the Haber-Bosch process which creates ammonia.
The Haber-Bosch process uses about one percent of the Earth's total energy supply in order to provide half of the nitrogen used in agriculture.
Excessive use of fertilizer can lead to algal blooms in streams that receive the run-off from the land being fertilized, and leads to long-term degradation of the soil.