Biol 4- fertilisers and nutrient cycles

HideShow resource information
Why are fertilisers needed in an agricultural ecosystem?
To replace the lost ions which were taken up by crops. They also allow photosynthesis to be maintained.
1 of 10
Why do nitrogen fertilisers reduce species diversity?
The nitrogen-rich soils favour the growth of grasses, nettles etc... so these weaker species get outcompeted.
2 of 10
How do fertilisers increase crop productivity?
They add essential nutrients needed for plant growth, increasing photosynthesis, and hence productivity.
3 of 10
Suggest a reason why, after a certain point, the addition of more fertiliser no longer improves the productivity of a crop.
Some other factor, e.g. light, is limiting photosynthesis. Only the limiting factor will increase photosynthesis and productivity.
4 of 10
Which stage in the nitrogen cycle involves the production of ammonia from organic ammonium-containing compounds?
Ammonification
5 of 10
Which stage in the nitrogen cycle involves the oxidation of ammonium ions in to nitrite ions and the oxidation of nitrite ions into nitrate ions?
Nitrification
6 of 10
Which stage in the nitrogen cycle involves the process by which nitrogen gas is converted into nitrogen-containing compounds?
Nitrogen fixation
7 of 10
Which stage in the nitrogen cycle involves the use of denitrifying bacteria converting soil nitrates into gaseous nitrogen?
Denitrification
8 of 10
Why is does soil need to be kept well aerated?
To prevent the build up of denitrifying bacteria
9 of 10
What are the two main human activities that have led to an increase in carbon dioxide levels in the atmosphere?
The combustion of fossil fuels and deforestation
10 of 10

Other cards in this set

Card 2

Front

Why do nitrogen fertilisers reduce species diversity?

Back

The nitrogen-rich soils favour the growth of grasses, nettles etc... so these weaker species get outcompeted.

Card 3

Front

How do fertilisers increase crop productivity?

Back

Preview of the front of card 3

Card 4

Front

Suggest a reason why, after a certain point, the addition of more fertiliser no longer improves the productivity of a crop.

Back

Preview of the front of card 4

Card 5

Front

Which stage in the nitrogen cycle involves the production of ammonia from organic ammonium-containing compounds?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Ecology, ecosystems and environmental biology resources »