Including Examiners Comments
R2102
PLANT NUTRITION & THE ROOT ENVIRONMENT
Level 2
Monday 20 June 2016
11:20 – 12:10
Written Examination
Candidate Number: …………………………………………………………………
Candidate Name: ……………………………………………………………………
Centre Number/Name: ……………………………………………………………..
IMPORTANT – Please read carefully before commencing:
i)
The duration of this paper is 50 minutes;
ii)
ALL questions should be attempted;
iii)
EACH question carries 10 marks;
iv)
Write your answers legibly in the lined space provided. It is NOT
necessary that all lined space is used in answering the questions;
v)
Use METRIC measurements only;
vi)
Use black or blue ink only. Pencil can be used for drawing purposes
only;
vii)
Where plant names are required, they should include genus, species
and where appropriate, cultivar;
viii)
Where a question requires a specific number of answers; only the first
answers given that meet the question requirement will be accepted,
regardless of the number of answers offered;
ix)
Please note, when the word ‘distinct’ is used within a question, it
means that the items have different characteristics or features.
Ofqual Unit Code R/505/2834
Please turn over/…..
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ANSWER ALL QUESTIONS
MARKS
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Q1 a) List FOUR characteristics of soil that affect its fertility.
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b) Describe THREE methods how a heavy clay soil can be improved for optimal plant
growth.
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Total Mark
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Q2 a) State TWO benefits and TWO limitations of using green manure.
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b) Describe ONE benefit to plant growth of EACH of the following soil constituents by
completing the table below.
Soil constituents
Benefits to plant growth
Soil organic
matter
2
Soil organisms
2
Soil mineral
nutrients
2
Total Mark
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3
Q3 a) Identify THREE materials used to influence soil pH.
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b) Name ONE plant suitable for growing in a soil with a pH of 6.5.
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c) Describe THREE factors which make a soil pH of 6.5 the most suitable for plant
growth.
i) ………………………………………………………….……………………………
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Total Mark
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Q4 a) State what is meant by the term parent rock.
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b) Describe the horizons found in soil by completing the table below.
Horizon
Name
Description
O
3
A
3
B
3
Total Mark
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MARKS
Q5 a) List FOUR properties to be considered when selecting growing media for plants in
containers.
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b) State TWO distinct differences between peat based and coir based growing media.
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c) State TWO environmental implications of peat in growing media.
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Total Mark
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iii) …...…………………………………………………………………………………
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Q6 a) Define the term soil structure.
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b) State the characteristics of EACH of the following soils by completing the table
below.
Sandy loam
Clay loam
Nutrients
2
Feel
2
Water
retention
2
Temperature
2
Total Mark
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©These questions are the property of the Royal Horticultural Society.
They must not be reproduced or sold.
The Royal Horticultural Society, Wisley, Woking, Surrey GU23 6QB.
Charity Registration Number: 222879/SC038262
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R2102
PLANT NUTRITION & THE ROOT ENVIRONMENT
Level 2
Monday 20 June 2016
Candidates Registered
Candidates Entered
Candidates Absent/Withdrawn
Candidates Deferred
517
436
73
8
Total Candidates Passed
Passed with Commendation
Passed
Failed
84.33%
14.12%
1.55%
374
184
190
62
85.78%
42.20%
43.58%
14.22%
Senior Examiner’s Comments:
1
Candidates should be able to demonstrate a good range of plant knowledge and be
able to give accurately named plant examples where appropriate. Common names
and generic names are often too vague and cannot be rewarded in the positive
manner that genus, species and where appropriate, variety/cultivar can. This is
particularly important when answering questions relating to particular (named)
plant(s). Marks can only be awarded for these narratives where the example(s) are
correctly and fully identified.
2
Candidates must be able to display accurate knowledge of the technical terms and
concepts detailed in the syllabus, in the context of horticulture and also be aware that
wider interpretation will not be rewarded. The examination should be regarded as a
possible introduction to higher level studies, which will only be open to those who are
in possession of a clear understanding of the horticultural terms and concepts which
are current.
3
The introductory rubric given on the first page of each question paper should be read
carefully by candidates. At each examination there are a significant number of
candidates who ignore or misread the instructions given and consequently may not
perform as well as they could have done.
9
4
Candidates should pace themselves during each paper. The most successful
candidates allow sufficient time to read the question thoroughly before answering it
and also take time to read through their answers. They should take care to write as
legibly as possible, so that the examiner is in no doubt about what is intended.
5
Candidates need to interpret key words within questions, particularly those such as
‘state’, ‘list’ and ‘describe’. Questions requiring descriptions or explanations obviously
require a more detailed answer than those requiring a list.
6
It is important to ensure that responses to questions are to the point. Candidates
should bear in mind that small sketches might be used to convey information more
succinctly than words.
7
Successful candidates ensure that their answers are focused and to the point. It is
disappointing when they cannot be rewarded for their efforts because the answer is
irrelevant to the particular question. Candidates should take note of the mark
allocation for specific sections and allocate their time and efforts accordingly.
8
Diagrams can enhance an answer and where appropriate can replace detailed
descriptions. They should be large, clear and well annotated, ensuring that labels are
properly attached to the features they describe. Diagrams should preferably be in
pencil. Colour may be used successfully but only where it is relevant to the answer.
9
In each examination it is clear that some candidates are ill prepared to answer
papers of the type set. It is essential that candidates have the opportunity to practice
questions. Ideally some papers should be answered in a time constrained situation.
Appropriate feedback must, in any case be provided.
10
Q1 a) List FOUR characteristics of soil that affect its fertility.
MARKS
4
b) Describe THREE methods how a heavy clay soil can be improved for optimal plant
growth.
i)
2
ii)
2
iii)
2
Q1a)
The majority of candidates listed acceptable characteristics of soil that affect its
fertility and were awarded full marks. These included:

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Soil structure
Soil texture
Organic matter content
Water/air content
Soil compaction
Capping
Q1b) Most candidates described a range of suitable methods to improve a heavy clay soil
and gained full marks. The best answers included:
i)
The incorporation of bulky organic matter, e.g. manure or grit, to open up the
pore space and allow air to penetrate and the soil to drain.
ii)
The use of green manure to protect the surface of the soil from capping and
subsequent digging in before seeding.
iii)
Single or double digging of the soil in the autumn to enable the winter frosts to
break up the large clods of soil.
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Q2 a) State TWO benefits and TWO limitations of using green manure.
MARKS
4
b) Describe ONE benefit to plant growth of EACH of the following soil constituents by
completing the table below.
Soil constituents
Benefits to plant growth
Soil organic
matter
2
Soil organisms
2
Soil mineral
nutrients
Q2a)
2
Candidates who gave distinct benefits and limitations of using green manures gained
full marks. Suitable answers included:
Benefits
 Prevents soil erosion as roots hold soil together so that the wind
cannot blow the soil away
 Foliage suppresses weed growth as it covers the soil
 Returns nutrients to the soil when it is dug in and improves the
soil fertility
Limitations

May harbour pests and diseases
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Uses ground that may be required for another crop

Need to incorporate them into the ground before they become woody or set
seed
Q2b) Candidates who provided a description of a benefit of the soil constituents to plant
growth gained full marks. Acceptable answers included:
Soil organic matter – has an effect on soil structure by opening up pore space in
heavy clay soils for air and water.
Soil organisms – make channels through the soil and allow better root penetration.
This improves aeration and drainage.
Soil mineral nutrients – these are required for growth, e.g. N, P, K. Nitrogen is for
boosting green leaf and stem growth.
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Q3 a) Identify THREE materials used to influence soil pH.
MARKS
3
b) Name ONE plant suitable for growing in a soil with a pH of 6.5.
1
c) Describe THREE factors which make a soil pH of 6.5 the most suitable for plant
growth.
i)
2
ii)
2
iii)
2
Q3a)
Full marks were gained by most candidates who correctly identified lime, sulphur and
organic materials, e.g. pine needle leaf mould, as materials used to influence soil pH.
Q3b) Most candidates named a suitable plant for a soil with a pH of 6.5, e.g. Spiraea x
arguta, Pyracantha coccinea ‘Lalandei’ and Malus domestica and were awarded full
marks.
Q3c)
Candidates who clearly understood soil pH were able to describe factors which make
a soil pH of 6.5 the most suitable for plant growth. Acceptable answers which gained
full marks included:
i)
At pH 6.5 most minerals are soluble and available for plant growth.
ii)
Very acid soils (pH 4-5) can contain high levels of aluminium, iron and
manganese which can be toxic to the plant.
iii)
Very alkaline soils lead to a lack of availability of some micro nutrients which
will affect plant growth.
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MARKS
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Q4 a) State what is meant by the term parent rock.
b) Describe the horizons found in soil by completing the table below.
Horizon
Name
Description
O
3
A
3
B
3
Q4a)
Candidates who stated that parent rock is where the soil originates from were
awarded full marks.
Q4b) The majority of candidates who named the horizons correctly provided good
descriptions for them and gained full marks.
O – Surface litter layer or organic layer which contains fungi, animal and plant
remains.
A – Topsoil which is dark in colour and contains the most organic matter, most of the
soil organisms, e.g. earthworms, and is the main root zone.
B – Subsoil which is pale in colour and has little or no plant/animal life and some root
penetration. In the subsoil there is an accumulation of clays/irons and the soil
structure is blocky with weathered rock fragments.
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MARKS
Q5 a) List FOUR properties to be considered when selecting growing media for plants in
4
containers.
b) State TWO distinct differences between peat based and coir based growing media.
4
c) State TWO environmental implications of peat in growing media.
2
Q5a)
Most candidates were able to list a range of properties to consider when selecting
growing media for plants in containers. Answers which gained full marks included:

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Ability to retain water
Good drainage
Nutrient value
Partially sterile, i.e. free from pests and diseases
Weight of the growing media
pH of the growing media
Q5b) The differences between peat based and coir based growing media that were
provided by candidates, and which gained full marks, included:

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
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Q5c)
Peat has a low pH and coir has a neutral pH
Peat retains a lot of water and coir has uneven distribution of water, i.e. it
looks dry when it is wet
Coir needs to be washed to remove salt before incorporation into the growing
media but peat does not
Peat is heavy and coir is light when wet in growing conditions
Candidates provided a range of suitable environmental implications of peat in
growing media, and were awarded full marks. Acceptable answers included:


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Peat forms naturally but very slowly in waterlogged lowland peat bogs. If
these are drained to extract peat then it will not reform
Bio-diversity is reduced if peat is extracted due to draining the bog
Peat acts as a carbon store. When it is extracted carbon dioxide is released
back into the atmosphere
Candidates who used the phrase ‘environmentally friendly’ could not be awarded any
marks unless it was qualified.
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MARKS
2
Q6 a) Define the term soil structure.
b) State the characteristics of EACH of the following soils by completing the table
below.
Sandy loam
Clay loam
Nutrients
2
Feel
2
Water
retention
Temperature
2
2
Q6a) The majority of candidates correctly defined the term soil structure as the
arrangement of the particles in the soil into aggregates/peds and were awarded full
marks.
Q6b) Most candidates were able to provide the characteristics of each soil and gained full
marks. Suitable answers included:
Nutrients – in a sandy loam soil the nutrients can leach out whereas in a clay loam
they are retained due to electrochemical properties.
Feel – a sandy loam soil feels gritty whereas a clay loam feels sticky and smooth.
Water retention – a sandy loam soil has poor water retention due to the large
particles which permit rapid drainage whereas a clay loam retains water and could
become waterlogged.
Temperature – a sandy loam soil is quick to warm up in spring whereas a clay
loam is slow to warm up due to its water content but retains heat longer.
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