5.4: Fertilisers Flashcards
Give an example of a natural/organic fertiliser
manure
How do natural/organic fertilisers contribute to soil quality
manure contains DOM - decays and contributes to soil structure and quality
what is one advantage of organic fertilisers over inorganic fertilisers
relies upon saprobionts and therefore mineral ions are released gradually and so reduces likeliness of leaching
How are inorganic fertilisers made
By obtaining nitrates and phosphates from rocks
What are 2 advantages of inorganic fertilisers over organic fertilisers
much more concentrated than organic fertilisers and so you can add in smaller volumes therefore reducing cost
can blend the fertiliser with known compositions to get the right balance for the specific plant
What are 2 advantages of using fertilisers
replaces mineral ions removed in harvest
increases crop productivity
What are 3 disadvantages of using fertilisers
reduces species diversity
leaching
eutrophication
How does using fertiliser reduce species diversity
N-rich soils favours grass which outcompetes other plant species and so reducing diversity
Fully explain the process of eutrophication
Leaching leads to increased nitrates in water
leading to algae bloom
increasing green coverage on surface of water
decreasing photosynthesis of plants underneath
many algae die and DOM settle on water bed
increase in DOM -> increase in saprobionts population
saprobionts respire aerobically and so increase of CO2 in water, decrease of O2 in water, therefore organisms in water die
Name 3 elements that would be found in inorganic fertilisers
potassium
phosphorus
nitrogen
Explain why agricultural ecosystems require the addition of fertilisers
crops absorb mineral ions from soil, farmers remove crops, decreasing mineral ions in soil
what does leaching mean
water soluble ions are removed from the soil and enter surrounding water bodies
what does eutrophication mean
excessive richness of nutrients in a water body causing an increase in algal growth
