Crop rotation is one of the most powerful tools that a farmer has for controlling weeds and maintaining fertility. Because organic farming places such a high priority on a well-designed crop rotation, Section II of this handbook focuses exclusively on this one aspect of farming.

The key to a good rotation is to have a diversity of crops - crops that are from different plant groups, that are seeded at different times and that have different nutrient demands. It is important to understand the principles of crop rotation so they can be adapted to your own farm. Unfortunately, copying a rotation used on a successful organic farm will not necessarily work because every farm is unique.

When choosing a crop to make up your crop rotation design, assess each crop in light of how many functions it can perform. These include:

- economic value as a cash crop

- importance as livestock feed

- role in building up the soil organic matter

- provision of adequate cover to protect the soil from erosion

- contribution or drain on the soil’s nutrient level

- ability to compete successfully with weeds

- inherent pest resistance

- possibility of its labor demands conflicting with other duties on the farm.

Legume crops, for example, can perform many functions. Legume forages are animal feed and can also be a seed crop. They help control weeds and pests and supply nitrogen for the crops that follow. Buckwheat can be grown as a cash crop and is also grown to control weeds and to accumulate phosphorus. Also its high fibre residue improves soil aeration and adds to the soil’s organic matter. Rye can be grown as a cover crop and to provide ample straw for bedding and composting; its allelopathic properties will help control weeds.