fertiliser and their effects

Question 1

why do plants need fertilisers in agriculture

Answer 1

minerals taken up directly by plants and animals are not returned there depletes the mineral ions which limits plant growth

Question 2

what are natural fertilisers

Answer 2

dead, decaying organic material and animal waste

Question 3

what is inorganic fertilisers

Answer 3

mined from rocks and then collected and blended usually contains npk

Question 4

what gives the best productivity

Answer 4

a use of both fertilisers together

Question 5

how do fertilisers increase productivity

Answer 5

plants use nitrogen forw growth, it is used to make new protiens and dna and amino acids which plants can use to photosynthesis grow larger leaves more photosynthesis so more sugars can be made

Question 6

how does nitrogen reduce species diversity

Answer 6

the nitrogen rich soil only favour rapidly growing plants thus those that grow slowly start to die leaving only those which grow fast to outcompete the others

Question 7

how does nitrates lead to leaching

Answer 7

the water can dissolve nitrogen and then move to the water leading to eutrophication

Question 8

how does leaching first occcur

Answer 8

the heavy rainwater, dissolve the ions found on the surface of the soil and carries it deep into the soil out of reach from the plants

Question 9

what happenes to the leached ions

Answer 9

they can find their way into water sources and can contaminate drinking sources people can get ill eg stomach cancer

Question 10

what is eutrophication

Answer 10

as a result of human influence a drastic change to the mineral concentration in fresh water sources

Question 11

what is there at the start of the eutrophication cycle

Answer 11

there is less nitrates in the water so the nitrate ions are a limiting factor

Question 12

what happens when the nitrate ions enter the water

Answer 12

the nitrate ions are no longer a limiting factior so the algae at the top of the surface of the water leading to algae bloom

Question 13

what does algae bloom do to the sunlight

Answer 13

it prevents the sunlight fro mreaching further depth of the water so these plants cannot photosynthesis and they later die

Question 14

what does the large dead matter cause

Answer 14

the dead matter is no longer a limiting reactant for the saproboints now there is a rich supply of food they can break down material more rapidly and they need to use energy so they respire

Question 15

what does respiration of the saproboints mean

Answer 15

this means there is less oxygen for the fish limiting reactant in the sea so they cannot respire and then die as a result

Question 16

what happens as the oxygen is used up

Answer 16

it increases the number of anaerobic saproboints