What is crop rotation
Crop rotation is the practice of growing the cabbage family, root crops and other crops such as peas and beans in succession on each part of a vegetable patch in a three-year cycle.
Purpose of crop rotation
It has two main purposes. First, since each type of crop makes different demands on the soil, changing crops each year ensures that the soil does not become exhausted of particular nutrients, and gives it a chance to recover its balance during the two years it is used for other crops. Second, moving crops discourages the build-up of pests and diseases which feed on one crop, and which starve without it.
Advantage of Crop rotation in modern small plots
Neither of these two purposes has nearly as much importance as it once had. Modern fertilizers – organic or artificial – can keep any patch of soil well stocked with all the necessary nutrients even if the same crop is grown year after year, as it often is on modern farms and modern pesticides can successfully keep most predators at bay.
Moreover, in a small garden, crop rotation won’t stop pests and diseases from following their favourite crops around the vegetable patch. Some pests can make their own way across the few meters involved others will get a lift on garden tools or your boots. Nevertheless, crop rotation does still have some value for the home gardener with a small patch, though not the traditional value.
By carving up the vegetable patch into three plots, it makes the annual chores of manuring, liming and fertilising seem less daunting – and encourages many gardeners to do a more thorough job.
How to do crop rotation
When planning a crop rotation system, think of vegetables in three groups: brassicas (the cabbage family, which includes some root vegetables such turnips): roots; and pulses (peas and beans) others. There is also a permanent group which remains in its own ground undisturbed by rotation. The main crops in each group are listed below, along with the order in which the as crops should be grown in each part of your patch and and how to prepare the soil for each group.
Crop rotation chart
|HOW TO GROUP VEGETABLES|
|Permanent crops||Brassicas||Roots||Pulses and others|
|Rhubarb Globe artichoke Asparagus||Brussels sprouts Cabbage Cauliflower Kale Savoy Sprouting broccoli Kohlrabi Radish Swede Turnip||Beetroot Carrot Chicory Jerusalem artichoke Parsnip Potato||Peas Beans Celery Onion Leek Lettuce Peppers Spinach Sweet corn Tomato Marrow|
|HOW TO PREPARE THE GROUND|
|For permanent crops||For brassicas||For roots||For pulses and others|
|Dig the soil thoroughly in autumn or spring, adding as much compost as you can afford.||Rake in general fertiliser. Add lime on all but chalky soils.||Don’t apply any manure before sowing root crops, except for potatoes in poor soil. Also avoid lime, but rake in a general fertiliser about two weeks before sowing or planting.||Dig in rotted manure or compost during the winter before planting. Or dig in peat and apply general fertilizer in the spring. Lime should not be needed once a rotation is established.|
|WHAT TO GROW WHERE|
|Plot one||Plot two||Plot three|
|1st year||Brassicas||Roots||Puises and others|
|2nd year||Roots||Pulses and others||Brassicas|
|3rd year||Pulses and others||Brassicas||Roots|