What is Fertiliser?
Fertiliser is any natural or manmade substance that improves the growth of plants and the fertility of soils. It can be organic or inorganic and contains chemical elements that provide one or more essential nutrients to plants.
Generally, fertilisers supply in varying but specific amounts the three major plant nutrients N-P-K (Nitrogen, Phosphorus and Potassium). Some fertilisers provide the secondary plant nutrients Ca, S and Mg (Calcium, Sulphur and Magnesium) and sometimes include trace elements which also have a role in plant nutrition (e.g. boron, chlorine, manganese, iron, zinc, copper and molybdenum)
Why is fertiliser needed?
Plants require nutrients for growth. Often our soils do not contain nutrients in the quantities required for optimum plant growth. This can be for a range of reasons but is frequently due to nutrient depletion caused by the removal over time of plant and animal products and by leaching or by gaseous loss.
These nutrients have to be replaced and this is done by applying fertiliser to the soil or in some cases, to plant foliage.
What is meant by organic fertiliser?
Organic fertilisers (composed of organic matter, i.e. carbon based) are derived from living or once living material and include manures, crop residues, compost and numerous other byproducts of living organisms. The percentage content of nutrients in organic fertilisers is less than in inorganic fertilisers.
What is inorganic fertiliser?
Inorganic fertilisers are derived from non-living sources and include most commercial fertilisers. In mineral fertilisers, the nutrients are inorganic chemicals, obtained by extraction and/or manufactured through chemical processes, e.g. the artificial synthesis of ammonia which can then be used to manufacture urea and ammonium nitrate and the reaction of sulphuric acid on rock phosphate to make superphosphate.
What are mineral fertilisers?
Mineral fertilisers are essentially a combination of naturally occurring fine mineral ores which can contain many essential multi nutrients e.g. P.K.Mg, Ca,Si and Trace Elements. They are not treated with acid and are used in blends
What is meant by acid soluble fertilisers?
Acid soluble fertilisers are chemically treated to make the nutrients soluble in water. For example, the addition of sulphuric acid to rock phosphate, which is not particularly water-soluble, converts the rock phosphate into a water soluble superphosphate form. The reaction of orthophosphoric acid with rock phosphate produces the water soluble, triple superphosphate. Hence the term acid fertilisers
For more information on fertiliser production visit http://www.fertilizer.org.au