grade 7 agriculture notes

STRAND ONE

CONSERVING AGRICULTURAL ENVIRONMENT

Soil pollution control
Definition: Soil pollution – refers to anything that causes
contamination of soil and reduces the soil quality.

It occurs when the substances causing the pollution
reduce the quality of the soil and convert the soil
inhabitable for microorganisms and macro organisms
living in the soil.

Soil contamination or soil pollution can occur either
because of human activities or because of natural
processes.

However, mostly it is due to human activities. The soil
contamination can occur due to the presence of chemicals
such as pesticides, herbicides, ammonia, petroleum
hydrocarbons, lead, nitrate, mercury, naphthalene, etc. in
an excess amount.

Causes of Soil Pollution

Soil pollution is a complex occurrence, and it can be
triggered by a variety of things and activities, from the
littering of cigarette butts to excess use of chemical
fertilizers.

Every cause is linked with another. It is quite difficult to
pinpoint one particular cause. However, the leading
causes are listed below.

Industrial Activity – Industrial activity has been the
biggest contributor to the problem of soil pollution,
especially since the amount of mining and manufacturing
has increased. Most industries are dependent on
extracting minerals from the earth. As a result, the
industrial waste lingers on the soil surface for a long time
and makes it unsuitable for use.

Agricultural Activities – The utilization of chemicals has
gone up tremendously since technology has provided us
with modern pesticides and fertilizers. They are full of
chemicals that are not produced in nature and cannot be
broken down by it. As a result, they seep into the ground
after they mix with water and slowly reduce the fertility of
the soil.

Waste Disposal – While industrial waste is sure to cause
contamination, there is another way in which we are
adding to the pollution. Every person excretes a certain
amount of personal waste in the form of urine and feces.
While much of it moves into the sewer system, there is
also a large amount that is dumped directly into landfills

in the form of diapers. Even the sewer system ends at
the landfill, where the biological waste pollutes the soil
and water.

Accidental Oil Spills – Oil leaks can happen during the
storage and transport of chemicals. This can be seen at
most of the fuel stations. The chemicals present in the
fuel reduces the quality of soil and make it unsuitable for
cultivation. These chemicals can enter into the
groundwater through the soil and make the water
undrinkable.

Acid Rain – Acid rain is caused when pollutants present
in the air mix up with the rain and fall back on the ground.
The polluted water could dissolve away some of the
essential nutrients found in the soil and change the
structure of the soil.

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Effects of soil pollution
Soil influences almost all aspects of our daily lives.
Sometimes we fail to understand it. As a result of this, we
sometimes fail to understand the effect that soil pollution has
on our daily lives. Polluted soil means stunted crops or even
a toxic underground water table. Some major effects of soil
pollution are: