crop production

Question 1

what conditions are needed to maximise growth of crops

Answer 1

-light source
-water source
-high temp
-high co2 conc

Question 2

how might we control these factors?

Answer 2

• polytunnels- allows optimal rates of photosynthesis

Question 3

what are the different products typically found in fertiliser, and what do they do?

Answer 3

• Nitrates- produce protein/ amino acids (and nucleic acids)
• phosphates - produce nucleic acids
• magnesium- produces chlorophyll needed for photosynthesis

Question 4

advantages of organic fertilisers

Answer 4

• improves soil structure
• releases minerals over longer period of time
• greater range of minerals
  -less cost to farmer- already available on farm

Question 5

disadvantages of organic fertilisers

Answer 5

• slow acting
• more difficult to apply
• may contain pests

Question 6

advantages of inorganic fertilisers

Answer 6

• mineral ions release immediately- fast acting
• contents known
• easier to apply

Question 7

disadvantages of inorganic fertilisers

Answer 7

• can lead to eutrophication
• requires regular reapplication - expensive

Question 8

advantages of pesticides

Answer 8

• reduces pests instantly
• can kill the whole population

Question 9

disadvantages of pesticides

Answer 9

• cost -needs to be reapplied regularly
• not specific- kills all insects
• pests can become resistant
• chemical can concentrate in all animals up the food chain

Question 10

advantages of biological control

Answer 10

• pest specific
• only initial cost needed- organism reproduces
  -pest not become resistant
• no effect on animals up food chain

Question 11

disadvantages of biological control

Answer 11

-takes time to reduce pest populations
-not all population killed
- expensive to re-populate (if required)