Crop Rotation

What is crop rotation? 

According to the Rodale Institute, crop rotation is the practice of planting different species of crops sequentially on the same plot of land to improve soil health, optimize soil nutrients, and combat pest and weed pressure. The focus is to ensure that crops of the same species/family are not grown repeatedly without interruption on the same field.

Foundational, different crop families will utilize different quantities of soil nutrients, this is because they have different nutritional requirements. Repeated planting of the same family of crops in the same location year after year will make those crops vulnerable to pathogens, pests, and will overtime deplete the soil nutrients for that family of crops. As a consequence there will be a reduction in yield, quality, increased pest pressure and disease.

In certified organically managed operations, it is required to select and implement tillage and cultivation practices to maintain or improve the physical, chemical, and biological condition of the soil, thus developing a good crop rotation plan is an integral part of that requirement. It has been well established that proper crop rotation maintains and preserves soil fertility. (§205.205 Crop rotation practice standard)

The crop rotation can include sod, cover crops/green manures that function to maintain and/or improve soil organic matter, manage pests in annual and perennial crops, and manage nutrient deficiencies or nutrient excesses while providing erosion control.  

Crop rotation is not a new idea or practice, in fact the Morrow plots at the Illinois Agricultural Experiment station has more than 100 years of observed effects of crop rotation, yields and soil composition.

How to set-up an effective Crop Rotation?

The short answer is, it depends on your farm's needs.  Your farmʻs crop rotation will depend on what you want to grow. Once you have settled on what you want to grow and how often, 

1. Separate the crops by family (Solanaceae, Asteraceae, Brassicaceae etc.). 

2. Then group them into light and heavy feeders. 

3. Based on your plots, plan how you want to plant them. There are a few good illustrations to show how the crop rotation plan can be organized. 

For the first year, it may not be critical to maintain the original crop rotation plan, which is a good time to make changes to your crop selection. After the first year or when the crop selection has been finalized, that is the time to implement your planned crop rotations.

Break crops, provide effective control of pests and diseases. Typically one year is sufficient to provide a break in the life cycle of pests, weeds, and disease depending on the environmental conditions.

The benefits of green manuring is gained from storing the organic matter and nutrients in the soil by improvement crops (i.e. cover crops, green manures etc.) and releasing nutrients by decomposition of the organic matter when they are the most beneficial to the following crop. 

Keep in mind that crop rotations will be specific to every farm, therefore, what one farms rotation plan is, may not work for another.