1. RHS Level 2
Certificate
Week 16 – Review Week: Soil
nutrients, limiting factors and relative
humidity. Study Skills – active
learning and mind mapping.
2. Learning objectives
Identify three active approaches to study
State three basic principles of mind mapping.
Draw a simple mind map for a macro nutrient
Explain the effects on plant growth of nitrogen,
phosphorous, potassium, calcium and iron in
normal quantities in the soil and in deficiency.
Explain the effect of air temperature on relative
humidity and how RH can be increased or
decreased
Explain the law of limiting factors and apply this
to photosynthesis and respiration to explain
increases and decreases in these processes.
3. Being an active learner
Active learners are engaged with their own
learning – deliberately seeking new strategies,
formulating their own questions, sharing ideas
and understanding.
A more interesting and engaging way to learn
– and more effective.
Learning is not something that is done to you –
it is something that you do yourself.
The more you work with information and apply
it, the better your recall and understanding will
be.
4. Mind Mapping basics
A visual record of the connections between ideas
and concepts, as well as the concepts
themselves.
Presents information in the way that the mind
perceives it, as a hierarchy with interconnections
– not a linear, left to right approach.
Uses colour, humour, images to make memories
and connections more powerful
The real benefit is making the mind map –
actively seeking to make connections between
ideas and information.
Lots of computer programs exist for this – but all
you need is paper and colour pens and your
information and creativity.
5. Stages to mind mapping
Chose a topic – this goes in the centre of a
landscape page. Keep it simple. Add
colour/pictures.
Select/identify the basic organising ideas
Link these to the topic with thick, coloured curvy
lines. One colour per BOI. Add images.
Thinner lines branch off the basic ideas lines for
the component/supporting information and ideas.
Keep words to a minimum – they trigger memory.
Use arrows and lines to show interconnections.
Bubbles, colour, highlights and pictures. Make it
fun!
6. Main Plant macro-nutrients
Nitrogen – essential for production of
chlorophyll and all metabolic processes.
Deficiency causes chlorosis, older leaves
first.
Phosphorous – root development,
germination, photosynthesis. Deficiency –
small, purple or blue tinged leaves.
Potassium – fruiting and flowering, cold and
drought hardiness. Deficiency – brown,
curled leaf edges, poor fruiting.
7. Other nutrients
Calcium – essential for cell wall formation; usually
plant deficiency is pH or drought related not an
absence in the soil. Low pH (acidity) makes Ca
unavailable. Deficiency – bitter pit in Apples,
blossom end rot in Tomatoes.
Iron – essential for chlorophyll; immobile in the
plant; usually deficiency is pH related not due to
lack in the soil. Alkaline soils may show iron
deficiency. Deficiency – interveinal chlorosis, young
leaves first.
8. Relative Humidity
The warmer air is the more water vapour it
can hold before it becomes saturated and
the water begins to precipitate out.
Cooler air can hold less water vapour and
becomes saturated with a smaller amount of
water vapour.
Relative humidity measures the temperature
of the air and what proportion of the total
amount of water vapour that the air at that
temperature can hold is actually present.
9. Limiting Factors
Where a chemical reaction is dependent on a
number of factors, the factor in least supply will
limit the speed/efficiency of the reaction.
Photosynthesis is the process in chlorophyll of
storing energy from the sun in carbohydrates.
Cellular respiration is the process (in the
mitochondria of cells) of releasing that stored
energy
Both are complex chemical reactions. Their
speed and efficiency can be limited by a
number of factors.
10. Learning outcomes
Identify three active approaches to study
State three basic principles of mind mapping
Draw a simple mind map for a macro nutrient
Explain the effects on plant growth of nitrogen,
phosphorous, potassium, calcium and iron in
normal quantities in the soil and in deficiency.
Explain the effect of air temperature on relative
humidity and how RH can be increased or
decreased
Explain the law of limiting factors and apply
this to photosynthesis and respiration to
explain increases and decreases in these
processes.