The Use of Fertilisers and Pesticides in Agriculture
Agriculture today dominates the majority of all land uses. As a result
it has a fundamental role in maintaining the countryside and
protecting the environment. The development of the use of fertilisers
and pesticides has dramatically increased the efficiency of food
production and has in fact more than quadrupled food production in the
last century. They also have reduced the cost and increased the
variety of foods available. However, there are serious consequences to
the uses of many of these pesticides and fertilisers and they have
resulted in various environmental problems.
In a natural ecosystem plants eventually die and decay. When the plant
dies, it decomposes and bacteria and other soil microorganisms break
down organic molecules and release the nutrients back into the soil.
However, in a farm, the plants (i.e. crops) are harvested and the
nutrients are removed with them. If a high yield is to be maintained
for a number of years the nutrients must be replaced. Therefore in
order to maintain productivity in agriculture farmers need to use
fertilisers containing these nutrients.
There are two types of fertilisers used by farmers in agriculture:
inorganic fertilisers and organic fertilisers. They both have
advantages and disadvantages within themselves. Inorganic fertilisers
are concentrated sources of macronutrients and can therefore be
applied in smaller amounts. As a result saving on transport costs and
on damage done by heavy farm machinery being driven over the soil.
They are also clean and lack the smell of organic fertilisers; and are
easier to handle and apply. Organic fertilisers add organic matter to
the soil. This can reduce the soil erosion and improve water-holding
properties. Also as it is often used as a waste product on mixed
farms, applying farm manure to a plant crop is a useful way of
disposing of this waste.
The most commonly used fertilisers are the soluble inorganic
(chemical) fertilisers. They are products of natural rocks; and
contain cations and anions in a concentrated form. These cations and
anions are the same as those that occur naturally in fertile soil.
There are usually three primary nutrients within these chemical
fertilisers (although are contained in organic fertilisers too); all
of which have certain properties playing an important part for
increasing a higher yield in agriculture. These are Nitrogen,
Phosphorus and Potassium (NPK).
· Nitrogen is fundamental for leaf growth, which is where
photosynthesis mainly takes place; therefore vital in increasing crop
yields. Nitrogen also contains a number of proteins, so therefore also
affecting the quality of the crop.
· Phosphorus is important for cell division so therefore is needed by
parts of the...