4. fertilisers and eutrophication

Question 1

crops harvested

Answer 1

1. crops take in minerals as they grow

2. crops removed, not left to die and decompose. mineral ions not returned to soil y decomposers

Question 2

animals/animal products removed

Answer 2

1. animals eat grass/plants taking up nutrients

2. nutrients aren’t replaced

Question 3

artificial fertilisers

Answer 3

inorganic
contain pure chemicals
soluble. more likely to leach into waterways

Question 4

natural fertilisers

Answer 4

organic
manure, composted veg, crop residue, sewage sludge
still contained in organic molecules that need to be decomposed. leaching less likely

Question 5

environmental issues

Answer 5

1. more fertiliser applied than needed
2. fertiliser leach into water ways (water soluble compounds in soil washed away e.g. by rain) -> eutrophication
3. too much of a nutrient can cause crops/plants to die

Question 6

eutrophication

Answer 6

1. mineral ions leached from fertilised fields.
2. stimulate rapid growth of algae in ponds and rivers
3. large amounts of algae block ligh reaching plants below
4. plants die (unable to photosynthesise)
5. bacteria feed on dead plants.
6. more bacteria = reduce oxygen in water through aerobic respiration
7. fish and other aquatic organisms die (not enough dissolved oxygen