Production of outdoor veg. & fruit rotations Flashcards
Fundamental aspect of organic gardening/growing
It is the growing of vegetable crops in a fixed succession to avoid the same plant families being grown in the same place year after year.
Benefits of rotation
Soil structure can be maintained by growing crops that have different cultivation requirements.
- Good management of soil fertility. Avoids over-depletion of nutrients and makes the best use of the application of organic matters and fertilisers.
- Avoids pest and, particularly, disease build-up. Soil-borne pathogens will increase if hosts are present at all times.
- Reduces weed problems. Some crops suppress weeds. Different cultivation techniques take out different weeds e.g. potatoes and perennial weeds. Regularly cut leys / green manures can suppress annuals.
Limitations of rotation
Most pests are unaffected since they are mobile.
Not very effective in small areas.
Requires record-keeping.
Grouping of plants in their families can make them a bigger target for pests and make it easier for pathogens to transfer between plants.
Plant families
Beetroot Family (Amaranthaceae) - also includes Spinach & Chard
Squash Family (Cucurbitaceae) - also Cucumber, Pumpkin, Courgette
Carrot Family (Apiaceae) - also Celeriac, Celery, Fennel, Parsley, Parsnip.
Cabbage Family (Brassicae) - lots inc. Radish, Turnip, Swede.
Pea & Bean Family (Papilionaceae)
Lettuce Family (Asteraceae) - also Chicory, Endive.
Onion Family (Alliaceae) - Garlic, Leek, Shallot.
Potato Family (Solanaceae) - also Aubergine, Pepper, Tomato.
Sweet corn Family (Poaceae)
An example of a 4 Course Rotation
A 4-course rotation (also known as a 4-year rotation) would have 4 blocks. If this has been chosen, then the 9 families would have to be double-up.
- Potato family
- Pea and Bean family, and Lettuce.
- Cabbage, squash, and sweet corn family.
- Carrot, beetroot, and onion families.
Feeding requirements of the different families
Normally, grouping would be of families with similar requirements.
Also, to make the most of nutrients, a block of heavy feeders would be followed by medium feeders the following year. The year after that, plants with a low nutrient requirement could be grown in that space. The above example groups families’ feeding requirements in the sequence: high, low, high, medium.
A green manure could follow block 4 as a low requirement: green manure leys are a rest for the soil and a chance to rebuild fertility and improve soil structure. They can take up a whole block (making a 5 course rotation) or be fitted in between crops.
Quantities have a big bearing
Beds and raised beds
The growing area is kept distinct, permanently, from the paths - the beds are never walked on and all procedures are carried out from the paths.
A typical bed would be 1.25m wide (1-1.5m) with paths a minimum of 30cm (30-60cm). The length of a bed can vary considerably
Theoretically, the improved conditions should give a higher yield / m².
SEEDS & SOWING
Many can be sown directly in the ground, others would benefit from being sown indoors. A third alternative is a nursery seedbed – a small area of well-prepared land possibly with a protective structure e.g. a cold frame. – where the seeds are sown directly and the resulting plants moved to their final positions later.
Sowing indoors can be in trays, cells / modules (individual little compartments in a tray, like an egg box) or blocks. Blocks consist of special compost that can be formed into cubes and they are treated like cells, though without the plastic.
- The Benefits of Protected Cropping
1) Winter Crops - E.g. Autumn-sown Oriental Greens, Rocket etc. to over winter: will continue to grow given protection apart from the coldest days.
2) Early Crops - i) Carrots sown in February in a polytunnel, ready in May.
3) Unusual or Intolerant Summer Crops. E.g. Basil loves any extra heat.
4) Extended Growing Season - E.g. Tomatoes in a cloche continue cropping & ripening beyond outdoor types.
5) Frost Protection - E.g. Early-flowering fruit could be protected by fleece in spring.
6) Ripening - E.g. Windrowed Onions dry off under ventilated cloches.
- The Benefits of Protected Cropping
7) Quick Germination - Clear or black plastic put down before sowing warms the soil & can start up an early crop sooner.
8) Earlier Harvesting - Plantings made at the usual time can be advanced by using protective coverings.
9) Wind Protection - Strong winds stress plants: suck moisture from the leaves giving slow growth. Also the ’wind chill factor’.
10) Soil Protection - By covering the soil, deterioration of the soil structure can be prevented.
11) Pest and Disease Control - E.g. i) Tomato Blight: plants under cover are often less affected.
Protected Cropping Alternatives
Windbreaks: plants or artificial barriers used to reduce wind speed over plants
Soil Coverings: mulches protect the soil structure from the effects of heavy rain, retain moisture in the soil and suppress weed growth
Floating Mulches: sheets of material laid over the crop, preferably weeded beforehand, & held down around the edge by pegs, bricks or sometimes soil.
Cloches: effectively the same as the mulches but on a framework
Garden Frames; Cold frame, like low-level mini greenhouses
Cropping Continuity / Successional Cropping
One aim of vegetable cultivation is to extend availability for as much of the year as possible. This can be done using a mixture of techniques
Choice of cultivars these have different maturing times
Successional sowing repeat sowing at regular intervals e.g. lettuces
Propagation with protection sowing and raising plants indoors
Shading this can slow down growth and extend cropping
Protection at the beginning and end of the season to extend the cropping time
Seed chitting getting seeds to start germinating before sowing outside
Repeat picking by harvesting frequently the plants produce more crop
Intercropping
This is where one crop, usually smaller growing but with rapid growth, is raised between plants of a larger, slower crop.
Also of importance is the rotation and trying to match up families (e.g. radish or rocket between young Brussels sprouts) or plants can be used that don’t have their own block (e.g. lettuce between squash).
Green manures can be used in a similar way, being sown at the same time (or later) as planting of the crop. The green manure may be left in to occupy the land when the main crop has been harvested and removed.
Catch Cropping
Often confused with intercropping, this more commonly refers to the practice of growing a quick maturing crop on land available when one major crop has been harvested yet before the next one has gone in. For example, early potatoes could be harvested completely in July, and onions or broad beans sown / planted in October: the time in between could be used to grow a crop of lettuce.
Alternatively, a short term green manure could be sown to fill the gap.
Site Selection factors
Soil - Depth, texture is hard to change.
Aspect - Which direction land faces effects temperature and light levels.
Climate / Microclimate - Area, exposure, frost pockets, rain fall.
Access - Access and rights of way
Acreage - A suitably-sized plot should be selected
Root Stock
Used to improve limiting factors of space available, size of tree, soil type, P & D resistance
