Humans and the environment

04.12.2020
09:07:38
Biology- grade 10- Today’s topic-Humans and the environment - course book-292 to 294.
Main points-
Modern technology has resulted in increased food production:
Agricultural machinery is used to clear the land, prepare the soil and plant, maintain and harvest crops to improve efficiency.
Chemical fertilisers are used to provide minerals to increase the yield of crops.
Pesticide is a chemical that destroys agricultural pests or competitors:
Herbicides are chemicals that kills plants that compete with the crop plant for root space, soil minerals and sunlight.
Insecticides are chemicals that destroy the insects that eat the damage the plants.
Selective breeding to improve production by crop plants and livestock, eg. cattle, fish and poultry.

The negative impact of monocultures:

The whole point of crop farming is to remove a mixed population of trees, shrubs, wildflowers and grasses and replace it with a dense population of only one species such as wheat or beans.
Monoculture: when a crop of a single species is grown on the same land, year after year.
In a monoculture, every attempt is made to destroy organisms that feed on, compete with or infect the crop plant.
So, the balanced life of a natural plant and animal community is displaced from farmland and left to survive only in small areas of woodland, health or hedgerow.



Homework worksheet is given on organisms and their environment