In this article, you'll learn the history of crop rotation, as well as best practices and tips for how to work crop rotation into your own sustainable home garden.
It’s fascinating to see how far back we can trace crop rotation.
We are able to trace crop rotation back thousands of years ago to Mesopotamia (source) and China (source).
Around the 1600’s, the practice fell out of favor and instead a “fallow year” where a field was laid to rest with no cultivation started to be practiced (source).
During the mid-17th century in Britain, a system called Norfolk four-course rotation gave farmers a way to tend to the land, restore the soil, and have more food to harvest at the same time. This was inspired by work done in then-Flanders which showcased that adding in a forage crop year of turnips and cover supported the land more than a fallow year (source).
Dr. Washington Carver was a soil chemist who noticed that decades of monocropping cotton was stripping the soil of nutrients, and advocated for a combination of crop rotation and cover cropping as a way to restore the fields (source).
The benefits of crop rotation that farmers practiced over the last several millennia still holds true today.
The Leopold Center for Sustainable Agriculture at Iowa State University studied crop rotation from 2006 - 2014 and found that longer rotations of 3+ years gave the soil a boost in organic matter, microbes, and nutrient availability.
They also found that compared to a 2 year rotation system, a 4 year rotation had 40% less soil erosion, higher crop yields, and far less disease.
We’ve seen the benefits the soil health has on the environment in the past, so improving soil health with crop rotation is one of the ways that your garden can become a more eco-friendly system.
But there are more ways that crop rotation reduces the environmental impact of gardening, homesteading, and farming.
First, Iowa State University found that a 4 year crop rotation system used 92% less fertilizer. Less inputs overall means less emissions from transportation and application, less nitrous oxide emissions from the nitrogen fertilizer(source), and also less run-off into our waterways. In fact, compared to a 2 year crop rotation, a 4 year crop rotation resulted in 59% less fossil fuel expenditure.
Additionally, Iowa State found that 97% less herbicide needed to be applied to agricultural lands when they practiced a 4 year crop rotation.
Less disease, insect, and weed issues means that less chemicals are applied over all, and less crops are lost (source).
It’s interesting to note that crop rotation has been shown to increase the carbon sequestration rate of the land (source). For example, in Brazil, crop rotation paired with no-till farming sequestered .41 tonnes of soil organic carbon/hectare in 1 year (source).
Studies have shown that the soil and plant health benefits of crop rotations gives plants a better chance of surviving hurricanes and heavy rain events (source).
As we’ve seen in the past years with fertilizer shortages, another point for crop rotation is that less nitrogen is needed, and there’s more phosphorus absorption overall by the plants.
As climate change can also bring about increased pest pressure, disease, and less rainfall, crop rotation would help plants during these situations as well.
The idea of rotating crops is simple - it’s the execution and planning that can be difficult.
I’m a total nerd for record keeping in the garden, and crop rotation systems is one time where I think everyone should keep records. While i have a general idea of what I planted where 4 years ago, having it written down for reference really helps.
In my research, it seems like all of the written recommendations are based on years instead of plant cycles, but I have heard some gardeners on Youtube count a cover crop as 1 rotation, and each planting in a growing season as a rotation (example).
So for example, if you have 1 garden bed and fill it with peas in the early spring, and then follow those peas with a quick crop of beets, and then plant a buckwheat cover crop, that would be three plantings of different families in 1 year.
Some folks might say that you’d still need to wait 3-4 years before you plant peas or legumes in that bed, while others might say that you could plant legumes in that bed after just one more crop family being there.
We know that cover crops can help reduce soil erosion, suppress weeds, and improve soil fertility, provides nutrient sourcing, increases soil microbiota, and increases water retention (source).
This suggests that cover cropping can provide similar benefits to a crop rotation. But again, I could not find any studies done on systems where a cover crop was counted as a crop rotation.
I think that at the end of the day, as with anything, it comes down to your own needs, preferences, experiences, and observations. If you implement a system where 1 planting = 1 rotation, and don’t have any issues with disease or pests, then that does give you a lot more flexibility in what you plant where.
Another thing that doesn’t seem to have a clear answer is a system for those that intercrop. For example, I have one bed right now that is 4 x 12. In that bed are 2 short rows of garlic, 3 broccoli plants, some soy beans and pole beans, some left over potato onions, and a couple of just-planted squashes. While I won’t grow plants in exactly the same locations next year, I might grow the same crops in the same bed, just in different locations on that bed.
I think that in theory, a heavily inter-cropped bed is much less prone to disease and pest issues than a strictly mono-cropped bed. So for myself, I infer that the crop rotation can be a little more flexible in instances such as this.
If you haven’t read any of Ruth Stout’s books, I highly recommend reading some of them as her sense of humor and no-nonsense tone is endearing, even if you don’t plan on working with her method of growing.
In her book Gardening Without Work, she theorizes that if she is always renewing the ground with mulch (in her case, spent hay, but this can be done with organic straw as well), that crop rotation isn’t necessary (source).
If you’re not practicing cover cropping, intercropping, and/or no-till methods of gardening, then crop rotation is something to definitely look at.
Crop rotation has been practiced for thousands of years and has been shown to provide numerous benefits, such as giving the soil a boost in organic matter, microbes, and nutrient availability, reducing soil erosion, decreasing herbicide and fertilizer use, increasing carbon sequestration rates, and increasing climate change resiliency.
If you are practicing cover cropping, intercropping, and no-till methods of gardening, and are working with multiple sowings in 1 year, then you may want to look at crop rotation from a different perspective than a large farm monoculture.
The environmental benefits here are where I think it’s worth it. If we practice all four methods - cover cropping, interplanting, no-till, and crop-rotation - we are maximizing our soil health and minimizing our environmental impact.
