lecture 11

Question 1

what is nitrification

Answer 1

it is the process by which NH4 is converted to NO3

Question 2

what bacteria is nitrification performed by?

Answer 2

Autotroph bacteria

Question 3

what are the 2 steps of nitrification

Answer 3

1. ammonium (NH4) to nitrite (NO2), nitrosomonas bacteria
   - nitrite (NO2) is generally toxic to plants and mammals
2. nitrate (NO2) to nitrate (NO3), Nitrobacter bacteria

Question 4

what is ammonia volatilization

Answer 4

the transformation of ammonium into ammonia gas that gets lost in the atmosphere

Question 5

what causes ammonia volatilization to occur?

Answer 5

occurs with ammonium based fertilizers, greatest losses are observed with urea fertilizers

Question 6

how to stop ammonia volatilization?

Answer 6

incorporate surface applied urea-based fertilizers into the soil immediately after fertilization

Question 7

what is denitrification

Answer 7

process in which NO3 is converted into N2O and N2, nitrogen gas lost in the atmosphere

Question 8

what bacteria causes denitrification

Answer 8

heterotrophic bacteria

Question 9

when do the greatest losses of denitrification occur

Answer 9

when there is a shortage of oxygen in the soil

Question 10

well aerated soils vs poor aerated soils

Answer 10

Good: aerobic soils
Poor: anaerobic soils

Question 11

NO3 vs NH4

Answer 11

NO3 is prone to denitrification, and NH4 is prone to volatilization