Hey there!
Please go get your
interactive notebook!
Please read the board!
Monoculture
Polyculture
Polyculture
What are the tradeoffs of
monoculture?

Benefits:

Lack of diversity = potential loss
of crop to disease/pest

Easy to manage

Provides uniformity

Need for pesticides

Can be grown by few people as
long as they have large machines

Need for inorganic fertilizer
because crop takes particular
nutrient from soil

Loss of biodiversity from field
edges/cover crops
Monocultures are a banquet
for pests!
What are the tradeoffs of
monoculture?

Benefits:

Easy to manage



Lack of diversity = potential loss
of crop to disease/pest
Provides uniformity

Need for pesticides
Can be grown by few people as
long as they have large machines

Need for inorganic fertilizer
because crop takes particular
nutrient from soil

Loss of biodiversity from field
edges/cover crops
Fertilizers Nov 14
Each crop needs some of the
same nutrients . . .
 Nitrogen

But each crop
takes the same
nutrients out of
the soil each
time it’s grown.

Example: corn
uses a LOT of
nitrogen
 Phosphorus
 Potassium
 Trace
elements
So why do monocultures
require lots of fertilizer?
Make a double bubble to
compare:
Synthetic fertilizer

Made from natural gas

Help plants grow

Examples:

Miracle Gro

Ammonium nitrate

Scott’s turf builder
Organic fertilizer

Created from an
ecological process or
organism

Help plants grow

Examples:

Fish emulsion

Blood meal

Bone meal

compost
Fertilizer nutrients – what do
those numbers mean?
 Nitrogen
 Phosphorus
 Potassium
Houston, we have a problem
(and it’s linked to fertilizers!)
Next notebook
page:
Eutrophication
Nov 14
Eutrophication p 137

Each pair/tri needs a white board, 2 markers, and an
eraser – send a runner now! 

Re-read the paragraph on artificial eutrophication.

List the steps of eutrophication in your notebook.

Compare your list with your neighbor

Use your notes to draw a cartoon of the process on the
white boards.
Plant nutrients (nitrogen and
phosphorus) cause eutrophication
Other sources of plant
nutrients

Untreated sewage

Manure from livestock

Pet wastes
Hypoxic zones “Dead zones” –
form in the summer Gulf of
Mexico
So what can YOU do?
Eutrophication

Which pollutants are involved?

What are the sources of these pollutants?

How are monocultures involved in
eutrophication?

What are the effects of eutrophication?

Why does the dead zone form in the Gulf
near New Orleans?

Why should we be worried about the dead
zone?