Cultural operations Flashcards
1
Q
Methods of soil cultivation for vegetable production
A
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Single dig
- Primary cultivation method which involves inverting the top 30cm/spit of soil using a digging spade. This provides an opportunity to bury residues, annual weeds, and incorporate bulky organic matter.
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Double dig
- Involves inverting a second, deeper layer of soil. Used for creating new borders and deepening shallow topsoil. It can also be helpful where drainage needs to be improved.
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Hoeing
- Secondary cultivation method used to break soil cap, aerating the soil and creates a tilth.
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Mechanical/rotary cultivation
- turning over the soil using a mechanical/rotary cultivator. Can cause problems with creating a ‘cultivation pan’. Should not be done on wet soil as will cause damage.
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Consolidation
- removes large ‘pores’ in which water/air might sit and prevent roots making intimate contact with soil.
- Fork over dug soil, rake level, and then lightly tread soil surface with heels of boots or tamp down with reverse head of rake to firm.
- Do not do this if soil wet or waterlogged to avoid compaction
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Tilth production
- Once consolidated rake over in two directions to break up clods and remove large stones, producing fine crumbly structure suitable for sowing seeds.
- Aim to produce a friable soil surface with a fine crumb structure
2
Q
Describe single digging
A
Primary cultivation technique involving digging 1 spade deep. Soil inverted to bury weeds and waste and allow organic matter to be incorporated. Carried out in autumn on heavy clay soils to allow frost to break down clods.
- Mark out a rectangular plot, mentally divide it into two strips, and lift a small trench, 30cm wide, and a spade’s depth, from the end of the first strip
- Place this soil to one side, leaving the trench empty. Then lift the same amount of soil from the area just behind, and drop it back, inverted, into the original trench, breaking it up a little
- Work methodically down the first strip, and then back up the second one, turning each trench into the space before it
- At the end, the final trench is filled with the soil that was left to one side from the first trench
3
Q
Describe double digging
A
- Mark out the area you are going to dig, then measure approximately 60cm back. Use a spade to dig out this area and temporarily place it to one side. At the end of digging the area, this soil is used to fill in the last trench
- Continue to dig the first trench, put the soil aside. The depth only needs to be the same as the spade blade
- Fork over the bottom of the trench. This is where the name ‘double digging’ comes from, as you dig twice the depth of usual, single digging
- Add organic matter, such as garden compost or well-rotted manure, to the base and lightly fork in
- Now measure approximately up the line another 60cm, and use a cane or stake to mark where to dig to
- Dig out the soil and place on top of the first trench (where the organic matter was incorporated)
- Once the soil is moved forward, repeat the process
- Be careful to keep the top surface level. This ensures that the soil isn’t shifted to one end
- Once reached the end of the plot, use a barrow to move the soil dug out at the beginning and pour it in the final trench to fill in the final top layer
4
Q
Describe what is meant by the bed system for growing vegetables
A
- Ground is broken up into number of permanent beds which are approximately <1.5m wide (reach middle from both sides) and 3m long
- Bed separated by paths 35-90cm wide.
- Ideally orientated north to south
- Raised bed is when soil is ‘thrown up’ to form beds with permanent paths separating them
5
Q
Benefits of using the bed system for growing vegetables (compared to open ground production)
A
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Benefits
- Width of bed enables centre to be reached from each side without walking on them
- Cultivation of beds carried out from paths which avoids soil compaction
- Enables intensive planting
- Efficient use of fertilisers (only on beds, not paths)
- greater depth of top soil (on raised beds)
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Compared with open ground
- bed system not walked on therefore soil structure is stable
- no soil compaction with bed system
- rooting zone deeper in bed system
- raised beds warm up quicker in spring than open ground
- More fertiliser and bulky organic matter required for open ground as applied to whole area not just beds
- In open ground plants need to be more widely spaced therefore lower yield per m2
- Wider plant spacing means that there is more competition from weeds.
6
Q
Explain what is meant by no-dig system of managing raised beds
A
- Beds or growing area not cultivated (dug) apart from initial set up. there is no need to dig them
- Preparation of no-dig bed involves removing all weeds and digging over before adding large amounts of organic matter to soil.
- Large amounts of organic matter added to surface only (not dug in), often in autumn so incorporated over winter by soil organisms
- Organic matter/soil improvers and fertilisers are spread over surface and incorporated into soil by organisms
7
Q
Reasons for using no-dig bed system
A
- No compaction of soil
- Allows soil to work in balance with soil organisms
- Soil erosion reduced
- Less disturbance of soil by digging so weed seeds not bought to surface, therefore reduced weeds
- Weeds are hoed off, hand weeded or mulched
- natural cycles of decomposition build up soil fauna
8
Q
Specification for typical raised bed and paths to include dimensions and materials
A
- Constructed from timber or brick
- Height >20cm
- Bed width 1.0-1.5m
- Bed length 1.8-4.0m
- 45-95cm path width to allow access for wheelbarrow or wheelchair
9
Q
Ideal time of year for soil cultivation
A
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Sandy soil
- can be cultivated all year round due to free draining properties, or in spring as dries out quickly
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Clay soil
- normally cultivated in autumn to allow frost to break down the clods
10
Q
Describe methods to extend the growing season
A
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Methods
- Cloches
- Cold frames
- Solid framed structure with glass or twin-walled polycarbonate cladding.
- Low tunnels
- Clear polythene (or fleece) stretched oved metal hoops which is dug into soil or weighted down.
- Black polythene
- Horticultural fleece
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Why
- protect crops from wind
- allow sun to warm the soil
- Frost protection for young plants
- enable earlier sowing/planting of crops
- act as barrier to pests
11
Q
Describe method of direct sowing vegetable crops
A
- Soil cultivated to fine tilth
- V-shaped drill created with back of rake along garden line.
- Base of drill watered
- Seed sown finely and evenly
- Drill backfilled and labelled.
12
Q
Describe tilth production
A
- Secondary cultivation technique to create fine crumb for sowing or planting
- Soil being roughly levelled by raking in two directions to break down large aggregates
- Soil then consolidated using feet to remove large air pockets
- final raking in tow directions to create fine level surface.
- Soil should not be worked when wet.
- remove stones
13
Q
What is meant by term ‘cultivation window’?
A
- ‘cultivation window’ is the optimum times to cultivate any soil type without damaging the structure.
- Cultivation is carried out when the soil is not too wet or too dry
- The ‘cultivation window’ can be very narrow and is ideally optimised before any inclement weather, including winter frosts.
14
Q
Describe a cold frame
A
- Used to extend growing season
- Solid frame constructed from timber or brick with glass/plastic/twin-walled polycarbonate lights
- May be situated directly on soil or solid base
- Crops protected from early frosts and enables crops to be overwintered
15
Q
Describe a cloche
A
- Used to extend growing season
- a solid frame with glass/plastic/twin-walled polycarbonate cladding.
- Glass cloches are usually heavy enough to withstand wind, plastic cloches need to be anchored to the ground
- Protect late crops from early frosts and heavy/damaging wind.
- Can be used to overwinter crops too.
