August 8, 2008
CHEMOSYNTHETIC ORGANIC and
What is a fertilizer?
Nutrients such as nitrogen and phosphorous are removed from soils by plant growth and need to be
replaced. Fertilizers are made of organic or inorganic materials produced from natural or synthetic
origins that are added to plant systems in order to supply one or more nutrients required for the
plants healthy growth.
A fertilizer is any material, organic or inorganic, natural or synthetic, that supplies plants
with the necessary nutrients for plant growth and optimum yield. All fertilizers can be
grouped into those that are organic or those that are inorganic.
Fertile soils are rich in nutrients, essential components which play a key role in plant
metabolism and growth. Crops take the nutrients they need from the soil, with the result that
soils can become impoverished if there is no process to replace these nutrients. Impoverished
soils reduce crop yields, and ultimately the economic viability of the farm itself. Mineral
fertilizer is now the major source of nutrients applied to soil.
Organic fertilizers are natural materials of either plant or animal origin, including livestock
manure, green manures, crop residues, household waste, compost, and woodland litter. Organic
fertilizers contain carbon, and more specifically, a carbonhydrogen linkage.
Inorganic (or mineral) fertilizers are fertilizers mined from mineral deposits with little processing
(e.g., lime, potash, or phosphate rock), or industrially manufactured through chemical processes
(e.g., urea). Inorganic fertilizers contain no carbon-hydrogen linkage and, thus, are not used as
an energy source by soil microorganisms. Although many inorganic fertilizers are naturally
occurring as minerals such as potassium nitrate, they are often synthesized to reduce costs and
Inorganic fertilizers vary in appearance depending on the process of manufacture. The particles can
be of many differen