1.1-1.5 Site and windbreaks

Question 1

Plot - size, soil, and exposure

Answer 1

Large plots: more versatile (eg crop rotation)

Enables use of machinery

Enables planting of widely spaced crops and fruit trees

Smaller size: converse is true

Texture/structure - sandy soils, light, easy to cultivate, free draining, warm up quickly. Not moisture retentive and leach nutrients - suited to root and salad crops

Clay soils - cultivated in autumn, warm slowly, delays sowing, suitable for brassicas and blackcurrants

Drainage - moisture retentive and free draining is optimum. Waterlogged soils lead to aerobic conditions. Blackcurrants more tolerant of poor drainage

Slopes - risk of erosion, frost pockets

Accessibility to water, electric and to wheelbarrows, machinery

Question 2

Limitations of a small garden

Answer 2

Difficult to rotate crops (or less effective)

Lack of space for top fruit

Difficult to grow permanent plantings eg. asparagus, rhubarb, soft fruit

May have to reduce optimum spacing

Not possible to use machinery

Question 3

Soil texture - significance

Answer 3

Liability to compaction

Aggregregate-forming ability

Cooling/warming properties

Nutrient-retaining ability

Drainage

Moisture-retention qualities

Question 4

Soil depth for food production

Answer 4

Vegetables 30cm

Fruit 45cm

Deep top soil provides:

Good anchorage for fruit trees

Unimpeded root growth for vegetables

More space for roots to spread and access nutrients

Question 5

Soil qualities desirable for most vegetables

Answer 5

Free draining

moisture-retentive

Good crumb structure (variety of pore sizes)

fertile

pH variable - alkaline for brassicas, acidic for raspberries, neutral suitable for most

neutral ensures fewer problems with diseases and nutrient deficiencies

Question 6

Aspect - part shade - vegetables that thrive
2

Answer 6

lettuce and runnerbeans

Question 7

Slopes - adverse effects
4

Answer 7

frost collects at bottom of slope
soil erosion
difficult to access machinery
access to site

Question 8

Frost pockets - locations
2

Answer 8

bottom of hills
depressions in landsape

Question 9

Frost - adverse effects
4

Answer 9

Inhibit germination of most seeds
Damage blossum (eg beans, fruit)
Shorter cultivation window
Damage to plant

Question 10

Windbreaks - living - advantages
5

Answer 10

Many are very long-lived if cultivated well
They can be decorative (blossoms, fruit, stem)
They can act as wildlife havens
Can be formal/informal
Wide range of suitable species

Question 11

Wind - adverse effects
4

Answer 11

Damage to plants

Support structures may be blown over
Discourage pollinating insects
Increase in rate of transpiration - can lead to scorching of leafy and tender plants
Wind chill can slow growth (esp in spring)

Blossom and fruit may be wind-blown

Question 12

Windbreaks - living - disadvantages
4

Answer 12

Require regular maintenance
Not instant fix (unless expensive)
They increase in size over time (can take up lots of space)
Compete with crop plants for light, water and nutrients
May harbour pests and diseases

Question 13

Windbreaks - living - examples
5

Answer 13

Fagus sylvatica
Carpinus betulis
Taxus baccata
Escallonia ‘Apple Blossum’
Crataegus monogyna

Question 14

Windbreaks - non-living - examples

Answer 14

• Mesh netting with posts at intervals (2-3m usually)
• Hit and miss fencing (chestnut)
• open patterned brickwork
• Wooden hurdles and trellising (eg hazel)
• Woven wooden or bamboo screens
• Coir or reed screens
• Proprietary windbreaks eg Paraweb

Question 15

Windbreaks - non-living - advantages
4

Answer 15

Can provide immediate protection
Takes up less space than living windbreaks
Remain the same size
Can be repaired/adapted as required (1m high provides protection 10m across)
Can blend well in garden (eg hazel)

Question 16

Windbreaks - non-living - disadvantages
4

Answer 16

Finite lifespan
Can be unattractive
Less likely to offer wildlife cover
If too dense can result in turbulence on the lee side

Question 17

Soil depth for food production

Answer 17

Vegetables 30cm

Fruit 45cm

Question 18

Soil qualities desirable for most vegetables

Answer 18

Free draining

moisture-retentive

Good crumb structure (variety of pore sizes)

fertile

Question 19

Soil texture - significance

Answer 19

Liability to compaction

Aggregregate-forming ability

Cooling/warming properties

Nutrient-retaining ability

Drainage

Moisture-retention qualities

Question 20

Double digging

Answer 20

Mark out plot. Dig a trench one spit deep and place at the opposite end of the area. Fork base of trench to one spit deep incorporating OM. Dig next trench, inverting soil into previous one. Continue to the end, final trench filled with soil from first trench

Question 21

Define cultivation window

Answer 21

It is the optimum time to cultivate any soil type, including a heavy clay or loam soil without damaging the structure. Cultivation is carried out when the soil in not too dry or too wet.

The window can be very narrow and is ideally optimised before any inclement weather, including winter frosts.

Question 22

Soil texture and food production

Answer 22

Texture refers to the proportion of clay, silt and sandy particles in a given soil and effects the suitability to provide a suitable root environment for crops. Whether a soil is sandy or a clay soil affects the variety of pore sizes, ability to form aggregates, nutrient holding ability, drainage and moisture retentive qualities and heating and cooling qualities.

For example:

Sandy soils warm up earlier in spring enabling earlier sowing and planting of crops

Sandy soils have poor moisture retention

Root crops eg carrots prefer sandy soil

Clay soils retain warmth for longer in autumn

Clay soils are slow to warm in spring

Clay soils are nutrient rich

Brassicas perform better on clay soils