The words ‘fertilizer’ and ‘manure’ are
used interchangeably in the context
of gardening, both referring to
substances added to soil for the
establishment, improvement and
maintenance of fertility.
By convention ‘fertilizer’ refers to a
substance applied in small amounts
which contains a relatively high
percentage of plant nutrients.
Fertilizers may be of organic or
inorganic origin, used either in their
naturally occurring state or more
often after some form of processing.
Organic fertilizers include substances
such as dried blood and seaweed
derivatives, which are of animal and
plant origins respectively. Inorganic
fertilizers are usually wholly
manufactured, as in the case of
sulphate of ammonia; or they may be
processed from a mined or quarried
mineral, as in the case of ground
limestone. Fertilizers may be
described as ‘straight’ where the
product contains predominantly
nitrogen, phosphate or potash, and
‘compound’ where there is a mix of
nutrients.
The word ‘manure’ is generally used
to describe bulky waste substances
high in fibre and water content with
relatively low levels of nutrients. Such
bulky organics are most commonly
represented by the mixture of farm
animal dung and bedding known as
farmyard manure. Composted plant
remains, farm slurry and sewage
sludge are other examples of bulky
organic manure. Thoughtful use of
fertilizers and manures can contribute
beneficially to various aspects of the
natural environment.

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Note added at 27 mins (2013-09-12 11:06:35 GMT)
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