Why Crop Rotation is Important

Pest Prevention

Crop rotation is very important to organic gardeners who grow crops in the same plot of land year after year. Crop rotation is practiced for pest and disease control. Plants within the same taxonomic family tend to have similar pests and pathogen threats. When you rotate crops, pests and pathogens that might have overwintered in the soil will not have their preferred food crop right at their fingertips allowing them to thrive the next year. In short, you have interrupted the pests’ life cycle and habitat. A good example of this is the Colorado potato beetle. The Colorado potato beetle likes to eat potato plants, but will also happily devour tomatoes, and eggplants. These beetles overwinter in the soil. If you plant eggplant in a spot where potatoes were grown the previous year, you could potentially devastate your yield when these little pests decide to come forth and multiply

Soil Nutrition

Additionally, by rotating crops you can help manage your soil fertility, as well as, build your soil structure. Different crops have different soil requirements and have varying effects on your soil. Some, like corn and tomatoes are heavy feeders that can quickly deplete soil of nitrogen and phosphorous. If you are continuously planting these same plants in the same location year after year the soil will run low on these nutrients. By changing the location that these plants are grown each year you can renew the plot where it grew the previous year, keeping the soil in balance. Legumes such as peas, beans are light feeders and actually add nitrogen to the soil. The general rule of thumb for balancing soil nutrition is to avoid planting crops of the same taxonomic family in the same place two years in a row. Longer crop rotations may be necessary. Sometimes waiting even as many a 3-4 years to grow the same plant in the same location is needed. Doing this can drastically reduce the number of problems incurred while growing, and thereby increase your rate of successful yields.

Quick Rules to Rotate By

  • Keep families together when planting, then rotate them together in successive years
  • Do not follow vegetables with other vegetables in the same family in successive years
  • Practice at least a three to four year rotation throughout your entire garden
  • Follow heavy feeders by light feeders
  • Follow shallow rooted plants by deep rooted plants

 

Successive Cropping

Successive cropping is when you follow one crop by another in the same season. The most important factor to consider with successive cropping is days to maturity and climatic conditions under which the second crop will mature under. In our Rocky Mountain growing season you can plan on a frost by mid-September. So if your first crop is harvested in August, this will give you time to get a crop in that matures in about one month and can stand up against a lite frost such as a transplanted leafy green or lettuce varietal.

Relay cropping

This is a type of successive cropping where the second crop is sown directly with a crop that is at its reproductive stage before harvesting.