IT’S A IT’S A GREEN WORLDGREEN WORLD

Plants need Plants need minerals toominerals too

Starter Starter

If you were growing geraniums in the If you were growing geraniums in the lab, list the things they will need to lab, list the things they will need to grow well.grow well.

Light, water, minerals Light, water, minerals

What type of minerals? What type of minerals?

Nitrates, phosphates, potassium and Nitrates, phosphates, potassium and magnesiummagnesium

Plants need minerals tooPlants need minerals too

Learning objectivesLearning objectives Explain that mineral Explain that mineral

deficiencies result in deficiencies result in poor plant growthpoor plant growth

Understand that Understand that fertilisers are added in fertilisers are added in improve crop yieldsimprove crop yields

Explain the uptake of Explain the uptake of minerals by active minerals by active transporttransport

Success criteriaSuccess criteria Be able to describe the Be able to describe the

effect of deficiency of effect of deficiency of certain minerals on certain minerals on plant growthplant growth

Relate the information Relate the information on packets of fertiliser on packets of fertiliser to mineral contentto mineral content

Show understanding of Show understanding of active transport by active transport by completing w/s B4d6completing 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?

lower leaves yellow and dead

weak stem

upper leaves pale green

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?

small roots

discoloured leaves

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 deficiencyTask – Mineral deficiency

Create a table to show the effects of Create a table to show the effects of the deficiency of the following the deficiency of the following minerals on plant growth:minerals on plant growth:

NitratesNitrates PhosphatesPhosphates Magnesium Magnesium PotassiumPotassium

Use p69 of the textbook to help youUse p69 of the textbook to help you

FertilisersFertilisers

3:6:93:6:9 10kg10kg

NPK FertiliserNPK Fertiliser

The phosphorus content:This fertiliser contains6% P2O5 (phosphates)

The potassium content:This fertiliser contains9% K2O (potash)

The nitrogen content:This fertiliser contains3% N (nitrogen)

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.

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.

Diffusion cannot take place against a concentration gradient.

Minerals are usually found in the soil in lower concentrations than they occur in the plant. Why can they not be transported by diffusion?

Instead, minerals enter the roots by active transport.

Active transport uses energy from respiration to move substances against a concentration gradient.

What is active transport?

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.

soil

mineral

root hair cell

Plants may take up some minerals in the soil but not others. Why is it important that plants select which minerals to transport?

Active transport

TaskTaskComplete B4d6 – Barley seedlingsComplete B4d6 – Barley seedlings

More sulfate ions are absorbed when oxygen is More sulfate ions are absorbed when oxygen is present (almost doubles)present (almost doubles)

RespirationRespiration Respiration releases oxygen, which is needed Respiration releases oxygen, which is needed

for the active transport of mineral ionsfor the active transport of mineral ions In soil, water and air occupy the same space; if In soil, water and air occupy the same space; if

there is too much water, there will be less, or there is too much water, there will be less, or not enough, air (oxygen) for respirationnot enough, air (oxygen) for respiration

Plenary

Transporting minerals

Plants need minerals tooPlants need minerals too

Learning objectivesLearning objectives Explain that mineral Explain that mineral

deficiencies result in deficiencies result in poor plant growthpoor plant growth

Understand that Understand that fertilisers are added in fertilisers are added in improve crop yieldsimprove crop yields

Explain the uptake of Explain the uptake of minerals by active minerals by active transporttransport

Success criteriaSuccess criteria Be able to describe the Be able to describe the

effect of deficiency of effect of deficiency of certain minerals on certain minerals on plant growthplant growth

Relate the information Relate the information on packets of fertiliser on packets of fertiliser to mineral contentto mineral content

Show understanding of Show understanding of active transport by active transport by completing w/s B4d6completing w/s B4d6