Transcript File

IT’S A
GREEN WORLD
Plants need
minerals too
Starter
If you were growing geraniums in the
lab, list the things they will need to
grow well.
Light, water, minerals
What type of minerals?
Nitrates, phosphates, potassium and
magnesium
Plants need minerals too
Learning objectives
 Explain that mineral
deficiencies result in
poor plant growth
 Understand that
fertilisers are added in
improve crop yields
 Explain the uptake of
minerals by active
transport
Success criteria
 Be able to describe the
effect of deficiency of
certain minerals on plant
growth
 Relate the information
on packets of fertiliser
to mineral content
 Show understanding of
active transport by
completing w/s B4d6
Not enough minerals!
What happens if plants do not get enough minerals?
Plants do not grow properly if they are deprived of minerals
and begin to look unhealthy.
If a plant does not get enough of a mineral it is said
to have a mineral deficiency.
Do mineral deficiencies affect a plant in the same way?
Mineral deficiency – no nitrogen!
Nitrogen is used for making leaves and is probably
the most important mineral for plant growth.
What is the effect of nitrogen deficiency?
upper leaves
pale green
lower leaves
yellow and dead
weak stem
Mineral deficiency – no phosphorus!
Phosphorus is used for making roots and is important
for all the other minerals used by plants.
What is the effect of phosphorus deficiency?
discoloured leaves
small roots
Mineral deficiency – no potassium!
Potassium is used for making flowers and fruit, so
crops are given extra potassium before they start to fruit.
What is the effect of potassium deficiency?
poor flower
and fruit growth
discoloured leaves
with dead spots
Mineral deficiency – no magnesium!
Magnesium is used for making chlorophyll
and so is vital for the process of photosynthesis.
What is the effect of magnesium deficiency?
upper leaves normal
(leaves turn yellow
from bottom upwards)
lower leaves pale green
or yellow
Task – Mineral deficiency
 Create a table to show the effects of
the deficiency of the following
minerals on plant growth:
 Nitrates
 Phosphates
 Magnesium
 Potassium
Use p69 of the textbook to help you
Fertilisers
By law the manufacturer of a product described as a ‘fertiliser’
must declare the nitrogen, phosphates and potash content on the
package. Also any other nutrients that have been added to the
product.
The nitrogen
content:
This fertiliser
contains
3% N (nitrogen)
The phosphorus content:
This fertiliser contains
6% P2O5 (phosphates)
3:6:9
10kg
NPK Fertiliser
The potassium
content:
This fertiliser
contains
9% K2O (potash)
How do minerals enter plants?
Like water, minerals enter plants through the roots.
However, they do this by different methods.
Water passively diffuses with a
concentration gradient from the
soil into the roots and up the stem.
Minerals are usually found in the
soil in lower concentrations than
they occur in the plant.
Why can they not be
transported by diffusion?
Diffusion cannot take place
against a concentration gradient.
Instead, minerals enter the roots by active transport.
What is active transport?
Active transport uses energy from respiration to move
substances against a concentration gradient.
soil
root hair cell
Specific minerals from
the soil enter through
channels in the cell walls
of the root hair cells.
The minerals then travel
around the plant in the
xylem vessels.
Plants may take up some
minerals in the soil but not
others. Why is it important
that plants select which
minerals to transport?
mineral
Active transport
Task
Complete B4d6 – Barley seedlings
 More sulfate ions are absorbed when oxygen is
present (almost doubles)
 Respiration
 Respiration releases oxygen, which is needed
for the active transport of mineral ions
 In soil, water and air occupy the same space; if
there is too much water, there will be less, or
not enough, air (oxygen) for respiration
Plenary
Transporting minerals
Plants need minerals too
Learning objectives
 Explain that mineral
deficiencies result in
poor plant growth
 Understand that
fertilisers are added in
improve crop yields
 Explain the uptake of
minerals by active
transport
Success criteria
 Be able to describe the
effect of deficiency of
certain minerals on plant
growth
 Relate the information
on packets of fertiliser
to mineral content
 Show understanding of
active transport by
completing w/s B4d6