Ever wondered what 'crop rotation' involves? It may not be applicable to community gardens but the concept is key to healthy planting. Some information for "edible edification"!
Why rotate vegetables?
First off, crop rotation moves different types of vegetables through the same garden bed. Crop rotation maintains plant health by reducing nutrient loss and helps plants to grow strongly. Different types of plants use different nutrients in the soil. If you continually grow the same crop in the same garden bed, over time this will result in nutrient deficiencies in the soil (unless fertility is maintained another way). When a different crop is planted in the following growing season, this reduces the probability of nutrient overuse/depletion. Another reason to rotate vegetables is to avoid plant disease, as rotating vegetables in a garden bed reduces infection of plant diseases carried in the soil.
There are two different types of crop rotation. The first method is crop rotation by plant type, and the second method is crop rotation by plant family. Each method produces the same results.
The four-bed crop rotation system:
The four-bed rotation by plant type is the simplest way to learn about crop rotation.
1. Prepare the soil for planting by either the no-dig method, sheet mulch, double-dig, or bio-intensive method. Ensure soil is loose so air and water are able to move through it. Also ensure plenty of compost is added to provide nutrients.
2. Plant a bed of legumes, then leafy green, then fruiting vegetable, then root crops in four separate beds. In the following season these crops will be moved into the following bed by moving the last crop type to the bed at the other end of the garden.
Garden Bed 1: Legume vegetables
Legume vegetables are the pod of which we eat, such as beans, broad beans, and peas. The soil will need average fertility. These crops will leave traces of nitrogen in the soil which will be used by the crops.
Garden Bed 2: Leafy green vegetables
Leafy green vegetables include lettuce, silverbeet, chard, cabbage, celery, chicory, endive, spinach, and Chinese greens. These greens need high levels of nitrogen for prime growth.
Garden Bed 3: Fruiting vegetables
Fruiting vegetables produce edible fruits and require a soil with balanced fertility that is humus-rich. These crops include tomato, chili, capsicum, corn, cucumber, eggplant, squash, pumpkin, and melon.
Garden Bed 4: Root vegetables
Root vegetables produce edible roots, or the underground parts of a plant including tuber or rhizome. Potato, radish, onion, carrot, beetroot, turnip, swede, oca, and yacon are all root vegetables. Less nitrogen is required, but more potassium is needed for good root growth.
Thanks to Australian City Farms & Community Garden Networks (ACFCGN).