4. Fertilisers and Eutrophication

Question 1

name one way that farmers can make up for a loss of nutrients

Answer 1

fertiliser

Question 2

what does fertilisers do?

Answer 2

they replace lost minerals, meaning more can be used for growth, increasing the efficiency for energy transfers

Question 3

name the two types of fertilisers

Answer 3

1. Artificial- inorganic, containing pure chemicals as powders or pellets
2. Natural fertilisers- organic matter such as manure

Question 4

name an envirnonmental issue as a result of fertilising

Answer 4

leaching

Question 5

what is leaching

Answer 5

water soluble compounds in the soil are washed away by rain or irrigation systems, due to excess amounts of fertilisers

Question 6

what can leaching lead to?

Answer 6

eutrophication

Question 7

outline eutrophication

Answer 7

• mineral ions leached from fields stimulate rapid growth of algae in ponds and rivers
• large amounts of algae block light from reaching the plants below
• this leads to plants dying as they can not photosynthesise fully
• bacteria feed on dead plant matter, decreasing oxygen concentration in the water as bacteria respire aerobically
• fish and other aquatic organisms die as there is not enough dissolved oxygen

Question 8

what is eutrophication caused by

Answer 8

excess nutrients