Nitrogen Cycle

Question 1

N Fixation

Answer 1

N2 gas fixed to an available form. Converted to NH3-

Blue, green algae/bacteria. Clostridium (free) or Rhizobium (symbiotic)

Question 2

Precipitation

Answer 2

air 78% N, rain contains N

Question 3

Ammonification

Answer 3

N is present in the soil but in a complex form/tied to organic matter and compounds (chemical)

H is decomposed by fungi and bacteria ‘mineralises’ becomes NH4+

Question 4

Nitrification

Answer 4

NH4+ ions are oxidised (broken down) to Nitrite NO2- then to NO3- (nitrate)

Nitrosomonas, Nitrobacter. Bacteria responsible