Saturday, April 8, 2023

The Earth’s Crust

Farming and Soil

Farmers add:

fertilizersmanurecompostand insecticides and herbicides

to their crops tohelp increase

their yields.

As a result, we can now grow more food than at any other time in the history of the earth.

As a result, we can now grow more food than at any other time in the history of the earth. However, this increase in food production does not come without a price.

The smells associated with the spreading of natural fertilizer (manure) can be very unpleasant for nearby towns, or the farm’s neighbours, and have even led to law suits.

The fertilizers and insecticides used on farms can find their way into rivers and streams and have a negative impact on fish and water ecosystems.

For example, these algal blooms were created when fertilizers from farms ran into rivers and lakes.

Once in the water, the fertilizers help the water plants grow.

Algal blooms (when algae grow and die quickly) are bad for an ecosystem because when the dead algae decompose they use up all the available oxygen – and fish and other animals in the water die.

An algal bloom as seen from space.

Farming can also lead to soil erosion.

Cutting and harvesting crops can slow the development of new soil and can steal vitamins and minerals from the soil.

When crops are cut, the soil is exposed to erosion by wind and rain.

Topsoil can dry out and be blown away or carried away during rainstorms.

Millions of tonnes of valuable top soil is lost every year because of erosion.

Erosion combined with a drought can even lead to desertification (the formation of deserts)

Such a thing almost happened during “the Dustbowl” of the 1920’s.

Farmers planted the same crop over and over and did not replace any of the nutrients.

The dry, nutrient poor soil just blew away.

This animation shows how soil and sand from Africa (the Sahara Desert) can blow across the Atlantic Ocean and land in North America.