R2102 4.2 Decribe a range of compost types

Question 1

Requirements of a compost (6)

Answer 1

1. To provide anchorage for the plant
2. To provide adequate air spaces for root respiration
3. To hold sufficient available water
4. To hold sufficient available nutrients
5. To be free of pathogens, pests and weeds
6. To be safe when handled by people

Question 2

Peat based composts (6)

Answer 2

1. Good air and water holding capacity
2. Few nutrtients so fertilisers can be added
3. Formed by partially decomposed residues of plants
4. Peat characteristics depend on the plant species and conditions they formed in.
5. Sphagnum peat moss is uniform and less decomposed than other types of peat and has ideal open structure for plants in containers.
6. Peat is not a sustainable product. It is also a significant carbon store

Question 3

Peat based composts (7)

Answer 3

1. Good air and water holding capacity. Safe to handle.
2. Few nutrtients so fertilisers can be added
3. Formed by partially decomposed residues of plants
4. Peat characteristics depend on the plant species and conditions they formed in.
5. Sphagnum peat moss is uniform and less decomposed than other types of peat and has ideal open structure for plants in containers.
6. Peat is not a sustainable product. It is also a significant carbon store
7. Takes many years to form and is use outstrips its regeneration
8. Peat is often imported e.g. peat in Wales being imported from Ireland
9. Used in past as soil improver but is being replaced by bark, green compost, spent mushroom compost and manure based products.

Question 4

Coir as compost (6)

Peat free

Answer 4

1. Coconut fibre. A geniune waste material
2. Excellent water holding ability
3. Mix of fine and coarse fibres hold air in is pore spaces
4. Used in composts as a bulking agent to increase moisture retention and porosity
5. Does not hold nutrients well
6. Environmental cost of importing it?

Question 5

Composted green waste (4)

Peat free

Answer 5

1. Local authorities and private companies collecting and composting green waste
2. Hugh nutrient content and high ph make it a good soil improver or mulch
3. Usually mixed with other materials so no more than 30% used
4. Now has quality assurance - BSI PAS 100

Question 6

Bark and wood fibre as compost (2)

Peat free

Answer 6

1. Pine bark commonly used. This is biologically active and suppresses some dieases. However it can take nitrogen from growing medium as it decomposes.
2. High pressure steam used to seperate wood fibre from chips. Resulting material has a low bulk density and is useful in a mixture with peat.

Question 7

Loam based composts (4)

Answer 7

1. Tyipified by John Innes composts
2. Loam sterilised to eliminate water borne fungi and insect pests
3. Main ingredients are: Loam, Peat, Sand, Fertiliser
4. Loam provides the main body of the compost. It contains essential micro-elements and some organic matter which provides slow release of nitrogen to the plant

Question 8

Two main John Innes composts

Answer 8

1. John Innes seed compost. 2 parts loam, 1 part peat, 1 part sand. Well drained ‘turfy clay loam’ low in nutrients.
2. John Innes potting compost. 7 parts ‘turfy clay loam’, 3 parts peat, 2 parts sand.

Question 8

Two main John Innes composts

Answer 8

1. John Innes seed compost. 2 parts loam, 1 part peat, 1 part sand. Well drained ‘turfy clay loam’ low in nutrients.
2. John Innes potting compost. 7 parts ‘turfy clay loam’, 3 parts peat, 2 parts sand.

Question 9

Use of multipurpose composts (2)

Answer 9

1. Sowing, root cuttings, potting on, hanging baskets.
2. Contains a balance of nutrients that can feed a plant up to 6 weeks
3. Can be peat based or peat free

Question 10

Use of seed composts

Answer 10

1. Low level of nutrients
2. For seed sowing and cuttings

Question 11

Use of seed composts (2)

Answer 11

1. Low level of nutrients
2. For seed sowing and cuttings

Question 12

Use of potting composts (2)

Answer 12

1. Support actively growing plants for six weeks
2. Thereafter supplementary feeding required
3. Used to repot plants that have outgrown containers or potting-on cutting which have a good root system

Question 13

Use of ericaceous composts (3)

Answer 13

1. Used for acid loving plants
2. Useful when growing ericaceous plants in alkaline soil
3. Examples of acid loving plants include: Azaleas, ferns, rhododdendron

Question 14

Use of hanging basket composts (4)

Answer 14

1. Contain higher levels of nutrients than multipurpose or potting composts
2. Also contain a wetting agent
3. Some also contain water absorbing granules
4. Hanging baskets have a high demand for nutrients and water

Question 15

Use of planting composts (2)

Answer 15

1. For mixing with the backfill soil when planting trees, shrubs or roses.
2. Helps the plants establish and are very rich in nutrients

Question 16

Use of houseplant composts (2)

Answer 16

1. Tend to have better areation due to the addition of perlite, vermiculite or sand. Better than potting or mutilpurpose composts for houseplants
2. May have also water holding material

Question 17

Use of specialist composts (2)

alpines, cacti, orchids, bonsai

Answer 17

1. May be particularly free draining and/or have specific additives (bark, expanded clay, loam)
2. Also have correct balance of nutrients for the plants in question

Question 18

Use of specialist composts (2)

alpines, cacti, orchids, bonsai

Answer 18

1. May be particularly free draining and/or have specific additives (bark, expanded clay, loam)
2. Also have correct balance of nutrients for the plants in question

Question 19

Use of growing bags (3)

Answer 19

1. Free from soil borne pests and dieases
2. Good structure and balance of nutrients for plant growth
3. Often used for tomatoes, cucumbers, peppers