Vegetable Crop Rotation

A crop rotation plan is essential for preventing eventual problems from soil-borne pests and diseases. By making certain that no one crop is grown on the same spot more than once in three years, pests and diseases are deprived of their host plants for at least two seasons, time enough, one hopes, for them to die of starvation.

In a three-yearly crop rotation system, vegetables can be divided roughly into three groups: brassicas (cabbage, brussels sprouts, etc.), root crops (onions, carrots, parsnips, etc.), and potatoes plus legumes (peas, beans, etc.). Although not ideal, it is a practical approach when only one or two rows of potatoes are grown.

The main reason why crop rotation is so necessary for continuous successful vegetable growing on a plot is that no two groups of plants take up nutrients and trace elements from the soil in the same ratio; so without a change of crop the soil nutrient levels are liable to become unbalanced. Another factor, perhaps not fully understood, is the difference in excreted waste from plant to plant. The more serious soil pests and diseases are related to individual groups of plants and do not attack vegetable plants outside the group. Potato eel- worm, for example, is confined to potatoes and tomatoes, both members of the same family. And clubroot, which attacks brassicas, often results from the neglect of crop rotation. Section A: root crops i.e. carrots, parsnips, etc.

Divide the vegetable growing area in to roughly three equal- sized sections. Having established the measurements of the plot, the plant develops as follows: - cabbages, etc.

In the fourth year it is hack to the cropping plan as for the first year.

There is scope here for variations and additions. Thus a row of quick-maturing ‘Fortune’ lettuce can be squeezed in alongside the first row of early peas; and there will be room for a few radishes in the brassica section, particularly as they are members of the same family. And when the early peas are cleared there will be a gap for more lettuce such as ‘Little Gem’. Take advantage of empty spaces but do not overcrowd or break crop rotation rules.