eutrophication

Question 1

what do fertilisers contain?

Answer 1

nitrates
potassium
phosphate

Question 2

why do crops need fertilisers?

Answer 2

nitrate –> nitrogen for amino acids and nucleic acids

potassium –> stomatal opening

phosphate –> nucleic acids and ATP

Question 3

explain the process of eutrophication

Answer 3

fertilisers leach into watercourses, increasing levels of nutrients

an algae bloom occurs, blocking out the light to plants below, meaning these plants die as they can’t photosynthesis

decomposers such as bacteria and fungi decompose the dead organic matter

these bacteria respire aerobically they use most of the available oxygen and creates a biological oxygen demand

aquatic animals die due to lack of oxygen

anaerobic bacteria then flourish

Question 4

what are three ways in which high nitrate levels in waterways can be overcome?

Answer 4

restricting the amount of fertiliser added to soil

only applying fertiliser when crops are actively growing –> readily taken up and does not remain in the soil

digging drainage ditches for minerals to concentrate in

Question 5

what can be a downside to digging drainage ditches for minerals to concentrate in when trying to overcome high nitrate levels in waterways?

Answer 5

a drop in invertebrate biodiversity

reduces species diversity in nearby grasslands