R3102 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS

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1 INCLUDING EXAMINERS COMMENTS R3102 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS Level 3 Wednesday 22 June :30 15:10 Written Examination Candidate Number: Candidate Name: Centre Number/Name:... IMPORTANT Please read carefully before commencing: i) The duration of this paper is 100 minutes; ii) iii) iv) ALL questions should be attempted; EACH question carries 10 marks; Write your answers legibly in the spaces provided. It is NOT necessary that all lined space is used in answering the questions; v) Use METRIC measurements only; vi) vii) viii) ix) Use black or blue ink only. Pencil may be used for drawing purposes only; Where plant names are required, they should include genus, species and where appropriate, cultivar; 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; Please note, when the word distinct is used within a question, it means that the items have different characteristics or features. Ofqual Unit Code M/505/2839 Please turn over/..

2 ANSWER ALL QUESTIONS Q1 a) Draw a labelled diagram of a brown earth soil profile. 4 2 Please see over/..

3 . b) Describe the advantages of a brown earth for plant growth. 6 Total Mark Please turn over/.. 3

4 Q2 a) Describe platy soil structure. 4 Please see over/.. 4

5 b) Describe TWO ways in which platy soil structure may lead to poor plant growth. 6 5 Total Mark Please turn over/..

6 Q3 a) b) A plot has a soil moisture deficit of 50mm. State what this means. Describe TWO distinct irrigation techniques stating an appropriate NAMED horticultural situation for EACH Please see over/..

7 Total Mark Please turn over/.. 7

8 Q4 Describe the carbon cycle with the aid of a labelled diagram Please see over/.. 8

9 . Total Mark Please turn over/.. 9

10 Q5 a) b) State what is meant by the term ectomycorrhiza. Describe how mycorrhizae affect EACH of the following in plant roots: i) water uptake; ii) nutrient uptake Please see over/.. 10

11 c) State THREE distinct horticultural situations where adding mycorrhizae to the growing medium would be beneficial for plant growth. 3 Total Mark Please turn over/.. 11

12 Q6 a) State the properties of EACH of the following constituents used for growing media: i) loam; ii) vermiculite Please see over/.. 12

13 b) Describe ONE NAMED horticultural situation where vermiculite would be used. 2 Total Mark Please turn over/.. 13

14 Q7 a) b) State what is meant by available water in the soil. Describe how the physical characteristics of soils affect their water availability Please see over/.. 14

15 Total Mark Please turn over/.. 15

16 Q8 a) Describe symptoms of iron deficiency in plants. 4 b) State TWO possible causes of iron deficiency. 2 Please see over/.. 16

17 c) Describe ways in which iron deficiency can be rectified Total Mark Please turn over/.. 17

18 Q9 a) State what is meant by the following terms in organic growing, giving a NAMED fertiliser for EACH: i) permitted; ii) prior approval required Please see over/.. 18

19 b) State FIVE methods by which organic growers can manage soil nutrient levels, other than by applying fertilisers Total Mark Please turn over/.. 19

20 Q10 Describe how organic growers manage EACH of the following: i) caterpillars; ii) apple scab Please see over/.. 20

21 ******* Total Mark 21

22 DO NOT USE THIS PAGE 22

23 DO NOT USE THIS PAGE 23

24 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: /SC

25 R3102 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS Level 3 Wednesday 22 June 2016 Candidates Registered 64 Total Candidates Passed % Candidates Entered 55 Passed with Commendation % Candidates Absent/Withdrawn 9 Passed % Candidates Deferred 0 Failed % Senior Examiner s Comments On the whole this paper was well answered with the majority of candidates attempting and completing all the questions. The following guidelines should be of help to future candidates. 1. Where named plant examples are asked for, full botanical names (genus and species) are required to achieve full marks. Common names will not be given a mark. 2. Use the command statements e.g. list or name (single words only), state (a few sentences), describe or explain (a fuller answer) together with the mark allocation, to judge the depth of the answer. Half marks are often allocated where the basic information given is correct but needs further qualification to gain the full mark. 3. Where a number of answers are specified in the question, the examiner will not select correct answers from a list e.g. if the question states State TWO plant names, only the first two names given will be marked. 4. Labels on diagrams should be correctly positioned to avoid ambiguity and diagrams should be clearly drawn and annotated. No marks will be awarded for artistic merit. 5. Candidates should use unambiguous plant examples as reference sources from, for example, the RHS Find a Plant Service available on the RHS Website. 25

26 Q1 a) Draw a labelled diagram of a brown earth soil profile. 4 b) Describe the advantages of a brown earth for plant growth. 6 Q1 a) Candidates were expected to draw a labelled diagram of a brown earth soil profile showing clear horizons. Good marks were awarded where candidates showed clear layers O, A, B, C. Fewer marks were awarded where labels were unclear or horizons were missing. Q1 b) Candidates were expected to explain advantages of a brown earth soil for plant growth. Brown earth soils are well structured and hold a good balance of air/water and are highly fertile. Higher marks were awarded where candidates included properties of brown earth soil which were beneficial to plants including good Cation Exchange Capacity (CEC), high Air Filled Porosity (AFP), high level of nutrients, humus, good levels of populations of micro organisms, leading to rapid breakdown/recycling of materials for nutrient release and many other factors beneficial to plants. Highest marks were awarded when candidates gave beneficial factors and clearly related these to advantages for plant growth e.g. High levels of micro organisms leading to release of nutrients available to plants, leading to good plant growth. CEC is good due to high levels of humus leading to good plant growth. Lower marks were awarded for simple statements such as good structure. No marks were awarded for how Brown Earths are formed. 26

27 Q2 a) Describe platy soil structure. 4 b) Describe TWO ways in which platy soil structure may lead to poor plant growth. 6 Q2 a) Candidates were expected to describe platy soil structures. High marks were awarded to those clients who clearly stated they are horizontal, plate-like aggregates, common in compacted soil, either in top layers or lower in the profile, forming a cap or pan, and of high bulk density with few vertical cracks. Some candidates provided annotated diagrams which assisted their description. Q2b) Candidates were expected to explain two ways in which platy soil structure led to poor plant growth. High marks were awarded for candidates who stated that platy structure reduced root penetration, caused sideways growth of roots, led to waterlogging and anaerobic conditions above the platy layer, or if at the surface led to run off. Highest marks were awarded to candidates who also related this to plant growth e.g. poor root penetration led to poor anchorage or poor access to water and nutrients below the plates. The best answers were those which directly related the structure of the soil to the effects on plant growth in clear statements. Q3 a) A plot has a soil moisture deficit of 50mm. State what this means. 2 b) Describe TWO distinct irrigation techniques stating an appropriate NAMED horticultural situation for EACH. 8 Q3 a) Candidates were expected to state what a soil moisture deficit of 50mm meant. High marks were awarded where candidates stated this meant 50mm of water needed to be applied by irrigation or rain to bring soil back up to field capacity. Q3 b) Candidates were asked to describe two distinct irrigation techniques, giving a named horticultural situation for each. High marks were awarded to candidates who clearly described an irrigation technique suitable for the horticultural situation given. Descriptions which gained good marks included irrigation coverage of the system, and also drawbacks and benefits of the systems if appropriate. Lower marks were awarded if an incorrect horticultural situation was given but the system was still described clearly and correctly, and no marks awarded where candidates described drainage systems, not irrigation systems. The highest marks were awarded where candidates clearly gave the correct irrigation system for a named horticultural situation, described it fully using correct technical terms, i.e. capillary tubes, rather than small pipes and included the lay out and method of operation. Generally well answered although some candidates described drainage systems instead of irrigation systems. 27

28 Q4 Describe the carbon cycle with the aid of a labelled diagram. 10 Q4) Candidates were expected to describe the carbon cycle with the aid of a labelled diagram. High marks were awarded to candidates who drew a clear diagram and included ten steps in the cycle with correct direction e.g. carbon dioxide in the atmosphere, absorbed by plants, fixed in photosynthesis, incorporated into soil animals or other consumers, released by decay, incorporated into microorganisms, stored by fossilisation, stored in peat, released from soil by tillage/cultivation, released back into the atmosphere by combustion and respiration, and other appropriate stages including sedimentation in the oceans, incorporation of calcium carbonates in sea organisms (shells). Lower marks were awarded to candidates who did not include some stages. Marks could also be gained if candidates included points in their narrative which they had missed in the diagram. Q5 a) State what is meant by the term ectomycorrhiza. 2 b) Describe how mycorrhizae affect EACH of the following in plant roots: iii) iv) water uptake; nutrient uptake. c) State THREE distinct horticultural situations where adding mycorrhizae to the growing medium would be beneficial for plant growth. 3 Q5 a) Candidates were expected to state what is meant by the term ectomycorrhiza. High marks were awarded to those who stated they were fungi living in symbiosis with plant roots which did not invade the plant cells but formed a sheath or Hartig net around the roots. No marks were awarded where candidates stated they were bacteria. Q5 b) Candidates were expected to describe how mycorrhizae affect i) water uptake and ii) nutrient uptake. In answer to b i) high marks were awarded where candidates stated that mycorrhizae greatly increase the surface area for water absorption and they can penetrate soil pores and extract water usually not available to plant roots. In answer to bii) high marks were awarded where candidates explained that mycorrhizae increase the surface area for nutrient uptake, secrete enzymes which help nutrient absorption, greatly increase uptake of phosphorus especially in acidic soil and ectomycorrhizae can break down organic matter to release increased supplies of nutrients. Q5c) Candidates were expected to state three distinct horticultural situations where adding mycorrhizae to the growing medium would be beneficial for plant growth. Marks were awarded where candidates stated appropriate situations including orchid seed propagation, planting into impoverished soil and planting bare rooted trees or shrubs such as Rosa spp

29 Q6 a) State the properties of EACH of the following constituents used for growing media: iii) iv) loam; vermiculite. b) Describe ONE NAMED horticultural situation where vermiculite would be used Q6 a) Candidates were asked to state the properties of loam and vermiculite as constituents of growing media. Some candidates answered by relating their knowledge of loam as a soil, not as a growing media constituent. i) Good marks were awarded where candidates stated loam having high cation exchange capacity (CEC), good air filled porosity (AFP), good buffering capacity, that loam provides stability to a growing medium and anchorage, with good water holding capacity. No marks were awarded for statements such as sterile as candidates must state that loam can be sterile if treated, it depends on the source. ii) High marks were awarded where candidates stated vermiculite had good CEC, good buffering capacity, good AFP, is sterile, very good water holding capacity but breaks down over time, is lightweight/low density or other appropriate properties. No marks were awarded for how it is produced. Q6 b) Candidates were expected to describe one named horticultural situation where vermiculite would be used. Marks were awarded to candidates who described its use in seed germination where light seed is covered with a thin layer of vermiculite, or it can be added to compost mixes to improve moisture retention and increase AFP. Other specialist uses of vermiculite in propagation were also credited. 29

30 Q7 a) State what is meant by available water in the soil. 2 b) Describe how the physical characteristics of soils affect their water availability. 8 Q7 a) Candidates were expected to state what is meant by available water (AW) in the soil. Available Water Content is the amount stored at field capacity (FC) minus water remaining at permanent wilting point (PWP), or moisture held in rooting depth between FC and PWP. Marks were also awarded to candidates who clearly stated that AW is water available to plant roots. Some candidates used a diagram to show this. Marks were awarded for either diagram or narrative. Q7 b) Candidates were expected to describe how the physical characteristics of soils affect their water availability. High marks were awarded where candidates clearly related soil particle size or particle aggregation and the resulting size and number of pore spaces to water availability. Lower marks were awarded to candidates who simply described drainage or water loss of different soil textures and no marks were given to candidates who simply described pore spaces. To gain marks candidates answers must be related to water availability. Marks were awarded to a statement such as good soil structure has a range of pore sizes and particle/aggregate sizes which provides a good range of meso, macro and micro pores resulting in water being available to plants over a long period. Candidates could also discuss water availability in specific soil texture types. For example a sandy soil has coarser texture so has more macro pores. Water is available initially in these pores but drainage is rapid so water availability diminishes over time. Clay soils have a preponderance of tiny pores, micropores, which hold water too tightly for it to be available to plants. Marks were also awarded to candidates who accurately described the effect of different soil structures on water availability, such as platy, structureless, blocky, prismatic and columnar soil structures. In a soil with columnar structures the initially available water drains rapidly but because it does not enter columnar structures it is unavailable to plant roots. This was generally well answered except several candidates having described pore sizes in detail then omitted to relate this to water availability. 30

31 Q8 a) Describe symptoms of iron deficiency in plants. 4 b) State TWO possible causes of iron deficiency. 2 c) Describe ways in which iron deficiency can be rectified. 4 Q8 a) Candidates were asked to describe symptoms of iron deficiency in plants. High marks were awarded where candidates clearly stated iron deficiency symptoms including interveinal chlorosis, with dark veins compared to lamina, yellowing and whitening of younger leaves, due to lack of chlorophyll production, poor fruit quality, and browning or necrotic patches on leaves. Iron is largely immobile in plants so symptoms mainly appear on younger leaves. Q8 b) Candidates were expected to state two causes of iron deficiency. Marks were awarded where candidates stated causes such as locking up of iron in soil due to presence of excess Copper, Manganese, Zinc, or Phosphorus. Also marks were awarded for other causes including over watering, and high ph of the growing medium, when iron is locked into insoluble compounds that are unable to be taken up by plants. High ph is linked to high levels of Calcium in soil; lime induced chlorosis due to lack of iron can be caused by over liming a soil. Q8 c) Candidates were expected to describe ways in which iron deficiency could be rectified. High marks were awarded for correct descriptions such as application of foliar feed containing soluble iron salts, adding chelates, sequestered iron such as EDTA, Iron sulphate (FeSO4) to the growing medium, reducing ph by adding organic matter or sulphur and other appropriate methods. Marks were also awarded where candidates stated chelates need to be regularly applied as they do not resolve the iron deficiency. 31

32 Q9 a) State what is meant by the following terms in organic growing, giving a NAMED fertiliser for EACH: iii) iv) permitted; prior approval required. b) State FIVE methods by which organic growers can manage soil nutrient levels, other than by applying fertilisers. 5 Q9 a) Candidates were expected to state what is meant by i) permitted and ii) prior approval required in organic growing, giving a named fertiliser for each. 2 3 i) Marks were awarded where a candidate stated that a permitted fertiliser, such as bone meal from an approved organic source can be used without reference to the approving authority. ii) High marks were awarded to candidates who stated that permission had to be sought from the organic approving authority before use of these fertilisers can be granted. Also, that the grower may have to submit proof of their need, an annual plan and that the approval can cover more than one use. An example would be Rock Potash. Some candidates wrote about permitted and prior approval pesticides in answer to part a) rather than fertilisers. Q9 b) Candidates were asked to state five methods by which organic growers can manage the soil nutrient levels, other than by applying fertilisers. High marks were awarded for statements such as planting legumes for nitrogen fixation and incorporating them into the soil, sowing green manure and digging it in before flowering, applying organic matter from an approved source and other appropriate methods. Lower marks were awarded where candidates stated simply using organic matter without saying its source must be organic. No marks were awarded where candidates stated use of organic fertilisers or home-made mixes such as comfrey tea, or where they recommended no dig systems as these do not maintain nutrient levels. Some candidates wrote about permitted and prior approval pesticides in answer to part a) rather than fertilisers. 32

33 Q10 Describe how organic growers manage EACH of the following: iii) iv) caterpillars; apple scab. 6 4 Q10 i) For management of caterpillars high marks were awarded where candidates included hand removal, protection of crop from egg laying adults with netting or mesh, application of parasitic nematodes, application of Bacillus thuringiensis in approved products such as Dipel or other approved organic pesticide, using sticky yellow traps for adult moths, and attracting insectivorous birds. Low marks were awarded for statements such as attract birds or attract predators as a fuller description was required. Identifying the species of bird (e.g. blue tit) or stating that the predators were insectivorous gained the mark. Q10 ii) For management of apple scab high marks were awarded where candidates gave methods of control including use of resistant cultivars, increasing spacing of the apple trees and pruning to increase air circulation, raking, removing and disposal of fallen leaves, use of neem oil, spraying with an approved sulphur or copper based fungicide and removing all infected material. 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: /SC

R3102 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS

R3102 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS INCLUDING EXAMINERS COMMENTS R310 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS Level 3 Wednesday 7 February 018 13:40 15:0 Written Examination Candidate Number: Candidate Name: Centre Number/Name:..