Life On Earth- Agriculture And Indicators Flashcards
What is monoculture?
Monoculture is growing a single crop or plant species over a wide area for a large number of years
Name 5 advances in agriculture
- monoculture
- increased use of fertilisers
- increased field size
- use of GM crops
- advancement in machinery
What are 2 advantages of monoculture?
It simplifies what machinery can be used
It reduces labour costs
What is a disadvantage of monoculture?
It decreases the biodiversity of an area
Give 3 features of intensive farming
- growing high crop yield in monocultures
- lots of chemical fertilisers
- animals are close together
What are the two categories of fertiliser?
Organic and chemical
What substances to fertilisers contain?
Nitrogen
Phosphorus
Potassium
NPK!
What problem environmentally can fertilisers cause?
Algal bloom
When fertilisers are washed into streams etc what is this called?
Leaching
The rapid growth of algae and them thriving in conditions is called …,,
Eutrophication
What does nitrogen help?
Leaf growth
What does phosphorus help?
Root growth
What does potassium help?
Fruit and flower growth
Name a chemical pesticide
DDT
Name an organic pesticide
Biological control
What is biological control
Farmers introduce natural predators of the pest to control pest numbers
What is bioaccumulation?
The build up of pesticide in top predators
What is an indicator species?
The presence or absence of a species that can indicate the conditions of an environment
What do mayfly and stonefly nymphs indicate?
Clean water
What do freshwater shrimp and caddis fly larva indicate?
Partly polluted water
What do the bloodworm and waterlouse indicate?
Badly polluted water
What do the sludgeworm and rat-tailed maggot indicate?
Very badly polluted water
What do lichen on trees indicate?
Sulphur dioxide levels
What lichen indicates zero or very low so2?
Hairy
What lichen indicates low so2?
Shrubby
What lichen indicates medium so2?
Leafy
What lichen indicates high so2?
Crusty
What are GM crops?
They are plants which have had their DNA modified to give the plant a new trait
Name a benefit of GM crops
They could help feed developing countries
Name a disadvantage of GM crops
They may have unpredictable health risks
