Syllabus/Unit: code: C2 Chemical Resources
Lesson number: 7
Lesson Title: Fertilisers and Crop Yields
Learning Outcomes
Learning Outcome 1:
Recall the three essential elements
needed for plant growth
Grade C
Learning Outcome 2:
Identify key fertilisers and explain how
they increase crop yields
Grade B
How I did
Targets
Connector:
What factors can
affect the healthy
growth of a
plant?
Learning Outcome 3:
Evaluate the negative impact of using
fertilisers
Grade A/A*
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Extended Learning
• Extended Learning task:
• Due date: next lesson
• Criteria for Grade C:
• Criteria for Grade B:
• Criteria for Grade A:
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BIG picture
Key Question: How are organisms
classified?
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What skills will you be developing this lesson?
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HSW- by planning and carrying out an
investigation/ Interpreting data/ evaluating an
experiment
Numeracy- by using formulae in calculations
Literacy- by writing explanations using correctly
spelt keywords and good grammar.
Team work- during a practical investigation
Self management- by completing an individual
assignment by …..
Participation- during a practical activity
Reflection- through self and peer assessment of
each outcome
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•
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•
•
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•How is this
lesson
relevant to
every day
life? Identify
and maintain
global
diversity
Where does this lesson
fit in to the rest of the
topic? Lesson 5
•Quick Discussion:
•What do you
already know?
22:25
Keywords:
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Essential elements
Eutrophication
Algal bloom
Aerobic bacteria
Nitrogenous fertiliser
Put your hand up if there is any key word from the
list that you don’t know the meaning of.
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New Information for Learning Outcome 1
•
Plants need certain elements to make them grow
properly. These three essential elements for plant
growth are:
1. Nitrogen (N)
2. Phosphorus (P)
3. Potassium (K)
•
These elements are found combined with other
elements in the soil – forming compounds called
minerals.
– E.g. Ammonium nitrate contains nitrogen,
potassium phosphate contains potassium and
phosphate.
•
Plants absorb water and dissolved minerals through
their roots. They cannot absorb insoluble minerals.
New Information for Learning Outcome 1
• Fertilisers are chemicals that provide plants with these
essential elements.
• They make crop plants grow faster and bigger, which increases
the crop yield.
• Since plants can only absorb minerals dissolved in water,
fertilisers must be soluble in water too.
• The world population is rising quickly, so we need to provide
more food – fertilisers help achieve this.
Demonstrate your
Learning for Outcome 1
Create
Evaluate
Apply (C)
Analyse
Understand (D)
Explain why fertilisers must be
water-soluble?
Apply
What is a fertiliser and
what does it do?
Understand
Remember (E)
Name three essential elements
for plant growth
Remember
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Learning Outcome 1: Review
Go back to your Learning Outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Learning Outcome
Learning Outcome 1:
Recall the three essential
elements needed for plant
growth
Grade C
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on Learning
Outcome 1?
22:25
New Information for Learning Outcome 2
• As plants grow, they absorb dissolved minerals from the soil.
• If a farmer removes a plant, these minerals are removed from
the soil; and as this continues, minerals in soil decrease.
• So fertilisers are important because they replace essential
elements used by previous crops. In fact they may even
provide extra!
• E.g. Plants need nitrogen to make proteins, and when fertilisers
use nitrogen supplied by plants, these plants grow even more
than usual.
New Information for Learning Outcome 2
•
Many of the fertilisers used around the world are
ammonia based, which is made via the Haber
process which you have studies earlier.
•
These so called nitrogenous fertilisers include:
• Urea, (NH2)2CO
• Ammonium nitrate, NH4NO3
• Ammonium sulphate, (NH4)2SO4
• Ammonium phosphate, (NH4)3PO4
• Potassium nitrate, KNO3, is also nitrogenous –
but not made directly from ammonia
•
Ammonia could be used on its own too, as a supply
of nitrogen, due to its solubility. But isn't usually
due to its sharp smell when not in a compound.
New Information for Learning Outcome 2
• However, how are fertilisers made?
• Fertilisers are made by neutralising acids with alkali. For
example:
• Nitric acid + potassium hydroxide = potassium nitrate
• The ammonia based fertilisers made as follows:
• Ammonia + nitric acid = ammonium nitrate
• Ammonia + sulphuric acid = ammonium sulphate
• Ammonia + phosphoric acid = ammonium phosphate
New Information for Learning Outcome 2
• You will now name your own fertiliser:
• See Sheet as follows:
Student activity 2.14.1
Lesson reference: 2.14 Making fertilisers
Book links: Page 154
Specification links: C2g
Keywords:
Demonstrate your
Learning for Outcome 2
Create
Evaluate
Analyse (B)
Describe how you could make
potassium nitrate from
potassium hydroxide and
nitric acid. Include all steps
and observations.
Analyse
Apply (C)
Explain what ammonum
nitrate is, hows its made
and why it allows plants
to grow taller
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Apply
Remember (E)
Understand
Remember
What type of fertilisers are
urea and ammonium sulphate?
Learning Outcome 2: Review
Go back to your Learning Outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Learning Outcome
Learning Outcome 2:
Identify key fertilisers and
explain how they increase crop
yields
Grade B
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on Learning
Outcome 2?
22:25
Eutrophication
Yet another example of pollution, eutrophication is when lakes become
stagnant due to careless use of fertiliser. There are six steps:
1) Inorganic fertilisers
used on fields are
washed into the lake
3) This growth causes
overcrowding and many plants die
due to lack of enough light or food
2) The increase in nitrates or phosphates causes the over growth of
algae – producing a thick green layer called algal bloom
Eutrophication
4) Micro-organisms like aerobic
bacteria increase in number due to
the extra dead material
6) The lack of oxygen
causes the death of fish
and other aquatic animals
Can’t…breathe…
5) These micro-organisms
use up the oxygen in the
lake during respiration
An algal bloom in a lake, caused by
over-use of fertilisers
Demonstrate your
Learning for Outcome 3
Create
(A*)
Describe the process of
eutrophication
Evaluate
(B)
Explain how a fertiliser
containing nitrogen
can lead to increased
plant growth
Analyse
Apply
Understand
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Remember
Learning Outcome 3: Review
Go back to your Learning Outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Learning Outcomes
Learning Outcome 3:
Evaluate the negative impact of
using fertilisers
Grade A/A*
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on Learning
Outcome 3?
22:25
Review for Remembering
• Stand up if you have met all three lesson
outcomes?
• If not what do you need to do next in order to
meet the outcome? Record this in your diary as
part of your homework.
• Is there any part of the lesson you think you
need to go over again next lesson?
• Tell the person next to you three things you have
learnt this lesson.
• How will you remember this for your exam?
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Science Department
Lesson plan
Teacher information
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