Ch 2 - Nitrogen Cycle

Question 1

Nitrogen

Answer 1

• 78% in the atmosphere.
• the most unreactive element.
• one of the most essential elements in the body.
• component for amino acids; plant protein + enzymes.
• human activity throws nitrogen cycle off balance. ex: fertilizers and burning of fossil fuels.

Question 2

Nitrogen fixation

Answer 2

Binding nitrogen gas into a more usable form (ammonia - NH3).
= contains bacteria to convert nitrogen into ammonium. e. g. legumes.
*most important step in cycle.

Question 3

Ammonification

Answer 3

The production of ammonia/ammonium products by break down of organic matter by decomposers.
Consumer/producer/waste is turned into ammonia.

Question 4

Denitrification

Answer 4

The microbial process of nitrogen being released back into the atmosphere, converting nitrate/nitrite back into nitrogen gas.

Question 5

How do farmers utilize soil bacteria to increase the productivity of their crops?

Answer 5

• soil bacteria allows for nitrogen to be absorbed into the plant.
• use of soil bacteria allows nitrogen to be used in the plant to make protein.

Question 6

Why is bacteria an essential component of the nitrogen cycle?

Answer 6

The bacteria fix (convert) nitrogen into ammonium, which is shared with plants.

Question 7

What form of nitrogen can plants use?

Answer 7

NO3- (nitrate): nitrogen source for plants.

Question 8

What makes ammonium?

Answer 8

Nitrogen-fixing bacteria in the soil and decomposers.

Question 9

1. What is denitrifying bacteria?
2. What releases it?

Answer 9

1. Reduces soil fertility because they convert useful nitrates back into ammonia.
   *fertility = create life.
2. Nitrate

Question 10

What’s crop rotation?

Answer 10

• growing legumes (alfalfa <— packs protein, clover) one growing season, and crops (corn, etc.) following season.
• helps maintain high nitrogen content in soil.