2.1-2.7 and 3.5-3.10 cultural operations to produce food

Question 1

Describe:

Single and double digging and rotary cultivation

Answer 1

Single: Turning the soil over to one spade depth

Double: Digging out a trench to one spit depth and forking in well rotted OM to the depth of another spit

Rotary cult.: use of a machine which chops and turns over the top soil

Question 2

Cultivation - timing

Answer 2

‘Cultivation window’ dependant on local climate and soil texture

Clay soils - in early autumn. Not too wet or too dry. Breaks up soil enabling frost to break up up large clods

Lighter sandy/silty soils - can be cultivated any time but avoid warm, dry conditions to avoid moisture loss, wind erosion and wet weather when rain can also lead to erosion and or capping. Light soils usually cultivated in spring prior to sowing/planting

Question 3

Advantages of ‘no dig’

Answer 3

soil organisms not disturbed

weed seeds not brought to the surface

moisture loss is reduced (not lost through cultivation and retained through mulching)

Saves work and time

Less risk of soil pans, caps and soil erosion

Question 4

Disadvantages of ‘no dig’

Answer 4

Pests/ eggs are not brought to the surface (eg slug eggs)

Perennial weeds may build up in the soil

Slow to remedy existing poor soil structure

Hard to apply to large-scale mechanised production

Question 5

Cultivation window

Answer 5

Dependant on soil type, weather and local microclimates

clay soils - autumn, avoid when wet

sandy/silty soils - usually spring, but avoid dry sunny days to avoid erosion and moisture loss. Rain can also lead to erosion and capping

Question 6

Advantages of ‘no dig’

Answer 6

Soil organisms remain undisturbed

weed seeds are not brought to the surface

Moisture loss is reduced (mulching and not exposing wet soil to evaporation)

Less work and time required

Avoids risk of soil erosion, cultivation pans and capping

Question 7

Disadvantages of ‘no dig’

Answer 7

Pests/eggs are not brought to the surface

Perennial weeds may build up in the soil

Slow to remedy existing poor structure

Does not lend itself to large scale mechanised production

Question 8

Define a bed system

Answer 8

Site is divided into narrow beds separated by paths, so beds are cultivated with no need to walk on them

Question 9

Bed system - dimensions

Answer 9

Can be raised to a height of 15cm with wood, bricks or concrete blocks (or more informally, soil thrown up from paths in between beds in mounds)

Beds can be any shape but are typically 1.2m (max 1.5m) wide x 3m

Paths: minimum of 0.5m

Question 10

Advantages of bed system

Answer 10

Lends itself to crop rotation

Avoids the need to walk on beds

Enables closer spacing of crops increasing yield

Can provide deeper top soil and improves drainage

Use of cloches and crop covers is easier (can also help warm soil)

Increases the cultivation window as plot is not walked on

Compost, manures and fertilisers can be applied to just areas where crops are planted

Lends itself to the no dig system

Question 11

Disadvantages of bed system

Answer 11

cost and time in building and maintaining edging

Cannot use machinery

Not practical for mass production

The layout and use of plots is less adaptable

Perennial weeds and pests such as slugs can be hidden under edging and paths (difficult to remove)

Question 12

Using greenhouses and cold frames

Benefits

Answer 12

Extends season by allowing for earlier sowing or extending growing season

Protects seedlings from pests and disease at a vulnerable stage

Early or late sowings of not fully hardy veg can be made in cold frames, GHs or later or earlier harvests

Also avoids pests and diseases (eg early carrots avoid carrot fly at the end of March through to May)

Growing early crops inside and others inside ensures continuity of supply (lettuce in GH for harvest in winter and spring and in situ from Spring for summer and autumn harvest)

Question 13

Using low tunnels and cloches

Answer 13

These temporary structures can be used to warm up soil allowing for earlier sowing

Can provide some frost protection early and late in the season and securing earlier/later harvests (extends by 2 weeks at both ends of the season)

Additional warmth will speed up growth

Question 14

Floating mulches

Define

Benefits

Example

Answer 14

Lightweight material temporarily laid over growing crop. Usually light and transparent - as crops grow the plants push up the material

Provide frost protection

Reduce cooling effects of wind

Can advance and extend harvest at both ends of growing season

Perforate polythene creates a greenhouse environment - protects from wind and traps heat from the sun. Edges secured by burying

Question 15

Enviromesh

Define

Benefits

Answer 15

Very fine netted plastic

Benefits

A barrier for pests such as carrot root fly

Can also provide some protection against frost and wind

Question 16

Mulches

examples and benefits

Answer 16

Dark coloured plastic polythene or ‘myex’ absorb heat and can be used to heat the soil prior to planting/sowing

Organic mulches also insulate the soil

Question 17

Propagation methods

Answer 17

In situ - direct slowing in drills/ trenches and thinning

Sowing in situ is best for plants such as root crops that do not transplant well (carrots, beetroots - drills potatoes - trenches

Station slowing (runner beans)

Transplanting

A seed bed can be used for plants that transplant well, to maximise successional use of space (leeks, brussel sprouts)

Sowing under cover

This is appropriate for tender plants before outside conditions are suitable, and for plants or cultivars that crop better with higher temperatures, such as some tomatoes and cucumbers

Sowing into modules, seed trays, pots or blocks and hardening off (pots - courgettes)

Broadasting (green manures)

Question 18

site options for sowing vegetables

3 options

Answer 18

Seed bed

A seed bed can be used for plants that transplant well, to maximise successional use of space

Under cover

This is appropriate for tender plants before outside conditions are suitable, and for plants or cultivars that crop better with higher temperatures, such as some tomatoes and cucumbers

In situ

Sowing in situ is best for plants such as root crops that do not transplant well

Question 19

Successional sowing

Answer 19

1. Sowing same variety at intervals to allow for longer harvest (radish)
2. Sowing early and late varieties of a crop (pots, carrots)

Question 20

intercropping

Answer 20

Growing a quick maturing crop in between slow growing cops eg, lettuce between brassicas or radishes between parsnips

Space so as not to deplete the main crop of resources

Question 21

catch crop

Answer 21

Quick maturing crops that will be required for a later main crop eg, Radish, lettuce. Green manures can be used to enrich soil and keep it covered

Question 22

Strip cropping

Answer 22

Cloches are moved between two or three strips of adjacent land so they cover three or four different crops at critical growth stages

Question 23

Irrigation - critical timing

Answer 23

At the seedling stage

At flowering and fruiting

At transplanting

At regular intervals for root vegetables and leafy plants

Question 24

Container types

Answer 24

seed tray - small/medium seeds for crops that cope with being transplanted (lettuce)

Modules - avoid root disturbance and space efficient

Pots - for plants with long propagation stage and for plants that are large when transplanted (courgettes)

Blocks - compressed coir - avoids root disturbance for large seedlings

Question 25

Spacing - impact and optimum

Answer 25

Spacing influences size of crop and yield

Optimum spacing allows for:

1. uniformity of growth
2. maximum yield
3. ease of management for grower

Question 26

Spacing considerations

Answer 26

1. Whether open plot or bed system (bed allows closer planting)
2. Desired space of cops for eg onions, beets and carrots
3. Soil quality - close crops suited to better quality soils with good reserves of nutrients and OM
4. Availability of irrigation
5. Weed competition - allow space to hoe on weedy plots
6. Ability to control P&D or tolerance of P&D (faster spread among closely spaced crops

Question 27

Factors significant to sowing

Answer 27

Timing

Preparation: digging, OM and fertilising

pH

Mulching

P&D protection

Irrigation

Spacing