What is Crop Rotation in Farming?
Many regenerative farming methods are based on traditional, pre-industrial agricultural practices, and crop rotation is no different. These days, however, we have more information and technology at our disposal to optimise and modernise the farming techniques used by our ancestors. Crop rotation has been used for centuries to improve crop yield and soil health. It forms an integral part of any transition to regenerative farming.
Our Managing Director, Justin Platt, remembers the ‘’old days’’ (1960-2000) when farmers were always very excited to plant into virgin soil because the reduced disease pressure and end result were so much more satisfying. The reason for this could largely be attributed to the natural harmony of the numerous species being in balance in the virgin soil. The second crop planted on the same land was also considered easier to manage, But from there on, the land would become unbalanced mostly from the tillage, monocropping, inorganic fertiliser and pesticides—and hopping onto the treadmill of trying to fix the impact of inputs with more inputs! The simple alternating of one crop to another the next year (preferably a monocot such as maize) to a dicot (such as soya, which also fixes Nitrogen) has similar benefits, but the virgin soil effect is considerably amplified by a multi-species cover crop, every two to three years.
What is crop rotation?
Crop rotation involves planting different crops in the same field in a systematic and planned manner rather than planting the same crop year after year on the same piece of land. Merriam-Webster’s definition of crop rotation: “the practice of growing different crops in succession on the same land chiefly to preserve the productive capacity of the soil.”
What are the benefits of crop rotation?
“The benefits of crop rotation and cover crops are so well documented that most farmers should not have to dwell too long on managing these.” – Justin Platt, RegenZ Managing Director
In today’s industrial agriculture, lands are often planted with a single crop year after year; this is known as monocropping. Monocropping leads to soil degradation and increases the risk of disease and pest outbreaks. A regenerative model, on the other hand, incorporates the wisdom of including crop diversity, cover cropping and crop rotations. Rotating crops across many fields encourages the restoration of healthy soil ecosystems. There is significant potential for crop rotation in farming to provide beneficial outcomes for the climate and beyond.
The role of crop rotation in soil improvement
An apple a day may keep the doctor away, but imagine you only ate apples? Sticking to one food can lead to deficiencies and health problems. Just as your body needs a variety of nutrients to stay healthy, so does the soil need a variety of crops to maintain its fertility. If you continue to plant the same crop year after year, you’ll end up depleting the soil of essential nutrients. Rotating crops ensures that the soil gets a balance of nutrients to improve its overall health.
Crop rotation helps farmers reduce the loss of soil nutrients by adding nutrients back into the soil, reducing soil erosion, and increasing soil organic matter. For example, crops like beans and peas (legumes in general) are known to fix nitrogen in the soil, which can help to improve soil fertility and increase crop yields, especially for crops like cabbage, cauliflower and kale, which benefit from the nutrient-rich conditions.
Creates a diverse environment for microbes to thrive
Because different crops have different requirements, they support different populations of microbes. As discussed, legumes have a symbiotic relationship with nitrogen-fixing bacteria, so these bacteria will thrive when plants such as beans and peas are grown. A new crop supports new microbes, leading to a more diverse and resilient microbial population in the soil. In turn, this microbial diversity helps reduce pests and diseases and improves overall soil fertility and health.
Reduces pest and disease pressure
Different crops are vulnerable to different pests and disease pressures. When the same crop is grown year after year, pests and diseases are able to establish themselves and build up in the soil. This can lead to poorer crop yields and increased use of pesticides. By rotating crops, farmers can disrupt the lifecycle of pests and diseases and make it more difficult for them to establish themselves in the environment.
Reduces the need for petrochemical-based fertilisers and pesticides
Modern agricultural methods create a vicious cycle of input application. Soils become degenerated due to monocropping, which means that plants need synthetic fertilisers and pesticides to grow and ward off pests since they’re not getting the nutrition they need from the soil.
Human health benefits
By reducing the need for synthetic chemicals and pesticides, farmers are able to grow crops more naturally and organically, resulting in fewer chemicals being ingested by consumers and more nutrient-dense crops for healthy diets and increased food security. Growing crops with fewer inputs also reduces chemical drift and the contamination of surface and groundwater.
Example crop rotations
There are many different types of crop rotation, depending on the crops planted, the environment, and the needs of the farmer. Common crop rotation examples include the three-year rotation system and the four-year rotation system:
Planting a different crop each year for three consecutive years, e.g.:
- Year one: cereal crop (such as wheat or barley)
- Year two: legume crop (such as peas or beans)
- Year three: root crop (such as potatoes or carrots)
A four-year rotation involves planting a different crop each year for four consecutive years. Farmers who grow a wide variety of crops use this system to rotate different crops in more complex and diverse ways.
How to implement crop rotation
To start a crop rotation cycle, farmers need to plan ahead and consider the specific needs of each crop:
- Length of the growing season
- Nutritional requirements
- Susceptibility to pests and diseases
Taking the needs of each crop into consideration, farmers can create a crop rotation plan that ensures that the right crop is planted in the right place at the right time.
Why is crop rotation important?
At RegenZ, we support farmers in their transition to regenerative farming. Crop rotation is one of the first steps they can take to improve soil health and fertility, and thus crop yields. It is a sustainable, regenerative and long-term approach to help farmers increase the productivity and profitability of their farms as costs and environmental stressors increase. Want to learn more about regenerative farming and crop rotation in South Africa? We’d love to hear from you!
About the Author: Justin Platt
Justin is the Founder & CEO of Zylem and RegenZ. Justin has a BSc in Plant Pathology and Botany from UKZN. He has been involved in the agricultural services industry since graduating in 1979. Justin has a passion for regenerative agriculture.