Crop rotation involves rotating the planting of different crops, each with different nutritional needs, in succession in the same space. Urban farmers can use crop rotation to maximize productivity and simultaneously improve soil fertility, as well as to help protect against plant diseases and pest infestation.
A sample crop rotation, as suggested by Thomas J. Fox in Urban Farming: Sustainable City Living in Your Backyard, in Your Community, and in the World (Hobby Farm Press, 2011), might be:
- Follow a heavy feeder (such as fruiting crops) with a light feeder (such as root vegetable crops);
- Follow a light feeder with a nitrogen fixer you plan to eat (such as peas);
- Follow a nitrogen fixer you plan to eat with a nitrogen-fixing cover crop (see below); and
- Return to the beginning and plant a heavy feeder.
Because urban farmers traditionally have small land bases, however, crop rotation can be difficult on urban farms, and requires careful and detailed planning.
For more information on crop rotation, see Crop Rotation on Organic Farms: A Planning Manual, a Natural Resource, Agriculture, and Engineering Service (NRAES) publication edited by Charles L. Mohler and Sue Ellen Johnson, 2009, available for free download or purchase at http://www.sare.org/Learning-Center/Books/Crop-Rotation-on-Organic-Farms.