R3102 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS

Transcription

1 INCLUDING EXAMINERS COMMENTS R310 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS Level 3 Wednesday 1 June :40 15:0 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/505/839 Please turn over/..

2 ANSWER ALL QUESTIONS Q1 a) List the stages in the formation of an alluvial sandy soil. State the range of particle sizes of sand according to the Soil Survey of England and Wales classification. MARKS 4 3 Please see over/..

3 . MARKS c) State THREE beneficial properties of coarse sand when used in a growing medium. 3 Total Mark Please turn over/.. 3

4 MARKS Q Describe how the characteristics of massive structure in a soil lead to poor plant growth under EACH of the following headings: i) water content; ii) nutrient availability. 8 4 Please see over/..

5 MARKS Total Mark Please turn over/.. 5

6 Q3 a) Define the term Air Filled Porosity (AFP). Describe the properties of TWO NAMED peat alternatives (organic materials) which can be used in growing media. MARKS 8 Please see over/.. 6

7 MARKS... Total Mark Please turn over/.. 7

8 Q4 Describe how the specific actions of TWO NAMED macro-organisms in soil are beneficial to plant growth. Please see over/.. MARKS 10 8

9 MARKS Total Mark Please turn over/.. 9

10 Q5 a) Label the diagram below of an iron pan podzol. MARKS 5 Describe the development of an iron pan podzol Please see over/..

11 11 MARKS Total Mark Please turn over/..

12 Q6 a) Describe ONE role of potassium in a plant. MARKS State TWO symptoms of potassium deficiency.. Please see over/.. 1

13 c) State TWO ways of rectifying potassium deficiency. MARKS d) Describe TWO effects on the plant of applying an excess of potassium fertiliser Please turn over/... Total Mark

14 MARKS Q7 a) Describe TWO NAMED liming materials by completing the table below. Material 1 Material Name Neutralising value Speed of action Please see over/.. 14

15 MARKS Describe how the buffering capacity of a soil affects the application of liming material. 4 Total Mark Please turn over/.. 15

16 Q8 a) Identify TWO NAMED horticultural situations for which an irrigation system is needed. MARKS A B Select ONE appropriate irrigation system for EACH of the situations named in a) by completing the table below: Situation A Situation B Name of irrigation system Reason 1 Reason Reason 3 Total Mark Please see over/.. 16

17 THIS PAGE IS INTENTIONALLY BLANK Please turn over/.. 17

18 Q9 a) State what is meant by the EACH of the following pest management practices in organic growing: i) biological control; ii) cultural control. MARKS Describe organic practices to control aphids Please see over/..

19 MARKS Total Mark Please turn over/..

20 MARKS Q10 Review crop rotation as a soil management technique in organic growing under EACH of the following headings: i) THREE Benefits; ii) TWO limitations Please see over/.. 0

21 MARKS ******* Total Mark 1

22 These questions are the property of the Royal Horticultural Society. They must not be reproduced or sold. The Royal Horticultural Society, Wisley, Woking, Surrey GU3 6QB. Charity Registration Number: 879/SC0386

23 R310 THE ROOT ENVIRONMENT, PLANT NUTRITION & GROWING SYSTEMS Level 3 Wednesday 1 June 017 Candidates Registered 76 Total Candidates Passed 73% Candidates Entered 63 Passed with Commendation 4% Candidates Absent/Withdrawn 1 Passed 49% Candidates Deferred 1 Failed 7% 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.. 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. 3

24 ANSWER ALL QUESTIONS MARKS Q1 a) List the stages in the formation of an alluvial sandy soil. 4 State the range of particle sizes of sand according to the Soil Survey of England and Wales classification. 3 c) State THREE beneficial properties of coarse sand when used in a growing medium. 3 Q1 a) Candidates were expected to list the four key processes in the formation of an alluvial sandy soil. i. The weathering of parent rock ii. Breaking the parent rock to particles iii. Transportation of these rock particles by water iv. The deposition of the transported rock particles Candidates who clearly stated this process were awarded full marks. Candidates were expected to give the range of particle sizes of sand as defined by the Soil Survey of England and Wales. Candidates who stated the correct range of sizes gained full marks. Coarse sand 0.6mm -.0mm Medium sand 0.mm - 0.6mm Fine sand 0.06mm - 0.mm Half marks were awarded to candidates who correctly gave one of the size range limitations correctly and the other incorrectly.marks could not be awarded where no unit of measurement was given. c) Candidates were expected to state three beneficial properties of coarse sand when used in a growing medium. Candidates who scored high marks stated three properties from the range below: Coarse sand is inert, and does not affect ph or nutrition has a high bulk density adds weight to a growing media is pest and pathogen free aids drainage of the growing media increases the Air-Filled Porosity (AFP) has no effect on Cation Exchange Capacity (CEC) Comments: This question was well answered with many candidates gaining a high number of marks. Some candidates lost marks by discussing sandy soils rather than the properties of coarse sand in a growing media, and either not stating units of measurement or stating incorrect units of measurement in part ( of the question. 4

25 MARKS Q Describe how the characteristics of massive structure in a soil lead to poor plant growth under EACH of the following headings: i) water content; ii) nutrient availability. 8 Q Candidates who gained high marks for i) were able to clearly relate the how the following characteristics of a massive soil influence water content and plant growth: High water content and its impact on plant growth Poor drainage and its impact on plant growth Poor gaseous exchange and its impact on plant growth Water held tightly/hygroscopically and its impact on plant growth Anaerobic conditions leading to ethanol production and its impact on plant growth Candidates who gained marks for ii) were able to clearly relate the how one of the following characteristics of a massive soil influence nutrient availability and plant growth: Massive structure lead to denitrifying bacteria so less available nitrogen Lower water uptake leading to nutrient deficiencies Poor root penetration could lead to less nutrient uptake. Anaerobic conditions result in lower organic matter break down and so fewer nutrients available for uptake Marks were awarded for any correctly identified characteristic when related to either water uptake or nutrient availability. Comments: Candidates who gained the highest marks gave clear and concise answers relating the characteristics of a massive soil to the effect these can have on water content and nutrient availability. Some candidates erroneously related their answer to other soil types and so did not gain marks for their answers. 5

26 MARKS Q3 a) Define the term Air Filled Porosity (AFP). Describe the properties of TWO NAMED peat alternatives (organic materials) which can be used in growing media. 8 Q3 a) Candidates who were able to state the formal definition of Air Filled Porosity gained full marks for this section of the paper, the percentage volume of the growing medium filled with air after the growing media has been saturated and after free drainage (gravitational drainage) has occurred. Candidates who stated valid and factually accurate properties of two named organic peat alternatives gained high marks. The properties could include ones that benefit plant growth or restrict it. Examples are given below: Peat alternative: Coir ph 5-6 good water holding capacity good CEC high buffering opens structure low nutrients Peat alternative: Bracken poor water holding capacity lightweight good AFP Peat alternative: Bark variable ph but mainly acidic, good AFP opens up structure low nutrients degrades over time Other peat alternatives were also credited. Comments Many candidates gained a high number of marks in this question, however some candidates gave a more generic description of AFP rather than the formal definition the question asked for. Some candidates stated inorganic alternatives to peat for which no marks were available. Some candidates discussed the environmental impact of the peat alternatives rather than their properties thus reducing the number of marks awarded. 6

27 Q4 Describe how the specific actions of TWO NAMED macro-organisms in soil are beneficial to plant growth. MARKS 10 Q4 Candidates who identified two soil macro organisms that had clear beneficial effects on plant growth gained the highest number of marks in this question. Answers which were detailed and discussed the specific actions of the macro organism on plant growth gained the highest marks. Good answers included specific information such as: Macro organism: Earthworms pull material down into topsoil from organic layer aerate the soil, the tunnels created aid gaseous exchange in the soil improve drainage with tunnels acting as drainage channels add organic material when they die and decompose digest plant material resulting in an increase in surface area for microorganisms to then act upon improve soil structure for roots to penetrate and other beneficial actions. Other beneficial macro organisms included ground beetles and woodlice. Comments Where the macro organisms were correctly stated this was a well answered question. Candidates who named micro-organisms, rather than macro-organisms, failed to gain marks. Some candidates selected macro-organisms, such as moles, with limited benefits to plant growth, and thus limited the marks that could be awarded to their answers. As the questions related to benefits, marks were not awarded to candidates who stated detrimental effects on plant growth, such as transfer of disease, or macro organisms eating plant parts. 7 MARKS

28 Q5 a) Label the diagram below of an iron pan podzol. 5 Describe the development of an iron pan podzol. Q5 a) Candidates who were able to accurately label the soil profile of an iron pan podsol gained full marks. Mor or O layer (organic layer was also an appropriate answer) Leached A horizon Bir horizon or iron pan B horizon C horizon/parent rock 5 Marks were also awarded for alternatively accepted names for layers including Bh and Bir. Candidates who described the stages in the development of an iron pan podsol gained high marks, major stages covered in candidates answers were: Iron pan podsols form in areas of acidic vegetation organic matter deposited on the surface rain percolating down through the developing soil moves humus particles and inorganic ions (eluviation) high acidity means iron ions are removed/leached from the A horizon this results in the A horizon being bleached deposition of ions and humus particles in B horizon (illuviation) iron deposited as a pan (creating the iron pan) Comments: Candidates who were familiar with iron pan podsols gained high marks in Part a) as they were able to correctly identify the layers in the profile. Part required a factual knowledge of the development of an iron pan podsol and candidates who demonstrated this knowledge gained high marks, however many candidates confused compaction formation of a pan with the formation of an iron pan podzol and so gained low marks. MARKS 8

29 Q6 a) Describe ONE role of potassium in a plant. State TWO symptoms of potassium deficiency. c) State TWO ways of rectifying potassium deficiency. d) Describe TWO effects on the plant of applying an excess of potassium fertiliser. 4 Q6 a) High marks were awarded where candidates correctly described one role of potassium in a plant including the following: production of ATP for photosynthesis as a catalyst for enzymes reactions for plant growth as an osmotic regulator in the opening and closing of the stomata increasing root growth and therefore yield increase drought resistance reduction of water loss and wilting cold hardiness Marks were awarded where candidates accurately stated two deficiency symptoms from the following: brown margins of leaves curling of leaf tips purple coloration reduced flowering poor seed and fruit development symptoms show first in lower leaves as potassium is mobile. c) Marks were awarded where candidates stated that potassium deficiency could be rectified by the addition of potassium rich fertilisers such as: potassium nitrate potassium sulphate monopotassium phosphate tomato feed comfrey feed seaweed meal wood ash d) High marks were awarded where candidates accurately described two possible consequences of applying an excess of Potassium: scorching of leaves a decrease of magnesium uptake (as potassium is antagonistic to it) reduced water uptake leading to wilting a shortage of other nutrients including zinc, manganese leading to deficiency symptoms such as yellowing of leaves Comments: Parts a), and c) were generally well answered and part d) was less well answered. 9

30 MARKS Q7 a) Describe TWO NAMED liming materials by completing the table below. Material 1 Material Name Neutralising value Speed of action Describe how the buffering capacity of a soil affects the application of liming material. 4 Q7 a) Candidates who gained high marks were able to state two distinct liming materials, their neutralising values (NV) and whether they were fast, slow or medium in action. For example: Calcium oxide, Neutralising value 100, fast speed of action. Candidates were awarded high marks where they stated: The greater the soil's buffering capacity the more lime was needed and the longer it took to change the ph. The lower the soil's buffering capacity less lime was needed and the ph altered more quickly. Marks were also awarded for clear definition of buffering capacity i.e. that it is the soil s ability to resist changes in ph and where candidates stated that clay has a higher buffering capacity than sand. Comments: a) Candidates who were able to correctly name two liming materials and accurately state the neutralising value and rate of action gained high marks. However many candidates whilst able to name the liming material were unable to give the neutralising value and so lost marks. Some candidates also lost marks by naming a material such as gypsum which does not have an effect on ph, or who gave the correct name of the liming product, but also gave its common name as the second product e.g. calcium oxide and quicklime. Generally this part of the question was well answered where a candidate had a clear understanding of buffering capacity. 30

31 MARKS Q8 a) Identify TWO NAMED horticultural situations for which an irrigation system is needed. A B Select ONE appropriate irrigation system for EACH of the situations named in a) by completing the table below: Situation A Situation B Name of irrigation system Reason 1 Reason Reason 3 Q9 a) High marks were awarded where candidates clearly identified two horticultural situations where an irrigation system was needed. The horticultural situations could include fields crops, the production of crops in greenhouses or polythene tunnels, turf-care or the establishment of plants in borders. Candidates who were able to correctly select a horticulturally appropriate system to meet the irrigation requirements of the stated situation received high marks. Microbore irrigation system in containerised plant production, pop up sprinklers in turf care and overhead spray lines in the production of salad leaves were all appropriate answers. The reasons for selections that related to the efficiency of water delivery, controllability of the system and the impacts on pest and pathogen populations, (for example the ability to irrigate without wetting leaves) were all appropriate answers which gained high marks. Comments: Generally this part of the question was well answered, however some candidates stated very limited situations relating to the watering of individual plants on a windowsill, for which no marks could be awarded. Generally well answered with good reasons given to justify the choice of irrigation system. 31

32 MARKS Q9 a) State what is meant by the EACH of the following pest management practices in organic growing: i) biological control; ii) cultural control. Describe organic practices to control aphids Q9 a) i) ii) A mark was given to candidates who stated that biological control was the use of a natural predator or parasite to control a pest. Half marks were awarded where an example was given with no definition to back up the example and thus demonstrate knowledge of the subject. A mark was awarded where candidates stated that cultural control was the use of growing techniques or good horticultural practice to control pests. Half marks were awarded where only an example was given. High marks were awarded where candidates described relevant and technically correct methods of control for aphids, that comply with the requirements of organic certification bodies such as the Soil Association. These could include: Comments: finger and thumb control of aphids the use of parasitic wasps in greenhouses the growing of healthy plants which are less susceptible to infestation nutritional management to reduce lush green growth removal of soft growth, such as the tops of beans to reduce infestations the introduction of predators the use of companion plantings to attract predators the use of mesh on greenhouse vents to stop aphids entering spraying off with water encouragement of predators through habitat creation e.g. bird boxes any other acceptable techniques including the use, with permission of natural pyrethrums and the use of fatty acids and horticultural soaps a) This part of the question was generally well answered although some candidates confused cultural techniques with physical pest control methods. This was generally well answered where the control methods related to organic crop production, no marks were available for answers relating to the use of products or techniques that did not comply with organic production principles. 3

33 MARKS Q10 Review crop rotation as a soil management technique in organic growing under EACH of the following headings: i) THREE Benefits; ii) TWO limitations. 6 4 i) ii) Candidates gained high marks where they stated that crop rotation avoids the build-up of soil born pests specific to the crop, so yields can be maintained, while pest populations can be managed or controlled. Good answers included reference to the use of crop rotation in the elimination of particular pests such as potato cyst eel worm by extending timing, the role of crop rotation in reducing the depletion of nutrients so yields do not reduce and enabling plants to grow healthily. Crop rotation can also be used to reduce soil erosion, can replenish soil with nutrients e.g. the growing of a legume crop prior to planting brassicas and can improve soil structure by alternating deep rooted and shallow rooted crops. It can also be used to control weeds to avoid competition and organise crops according to cultivation needs. Candidates who gained high marks stated the potential limitations accurately and realistically to include, the need to plan ahead, the difficulty of rotation if space is limited, the fact that crop rotation only controls soil borne pests, other non-soil borne pests may increase, not all growing systems are suitable for crop rotation, and it may restrict crop choice. Comments: This question was generally well answered. 33