Are you growing the same crops in the same spots year after year with diminishing returns? If so, this article is for you. Find out all about crop rotation and its benefits here.
Following a crop rotation plan will allow you to maximise your yields while minimising the occurrences of pests in your garden [Photo: Phil Darby/ Shutterstock.com]
Over time, cultivated soil loses its productivity. You will find that your crops do not produce the same yields, in addition to pest occurrences being more frequent and more severe. The good news is that this is all avoidable with crop rotation. Read on to learn about the basics of crop rotation and get advice on how to come up with a crop rotation plan for your own garden.
What is crop rotation?
Crop rotation is a system of gardening whereby you rotate the crops that you grow in a certain area in a certain season or year. This is done for a multitude of reasons, the most important being to avoid monocrop agriculture. Monocropping is when the same crop is grown in the same spot year after year, ultimately depleting the soil of nutrients. Some crops consume more nutrients than others, or consume specific nutrients, which will eventually be depleted and lead to deficiencies in the soil. There are three basic classifications of plants based on their nutrient consumption: heavy feeders, moderate feeders, and light feeders. Rotating crops planted in a certain location gives the soil a chance to recover.
Growing the same crop in the same location continuously will deplete the soil’s nutrients and allows pests and diseases to accumulate [Photo: Gabriele Rohde/Shutterstock.com]
Crop rotation also reduces the build-up of pests and diseases. When the same crop is grown in the same location every season, the specific pests and diseases the species is susceptible to will build up in the soil over time. One thing to note is that in order for crop rotation to be successful, you do need adequate space in your garden. Small gardens may not have enough area to distance the crops far enough apart to reduce the build-up of pests and diseases. In this case, plan a cultivation break for species that harbour pests or are susceptible to diseases. These cultivation breaks can last from several seasons to a couple years – as long as it takes for it to be safe to plant the crop again.
Legumes take nitrogen from the air and store it in root nodules in the soil, ultimately increasing the nitrogen content of the soil [Photo: Vadim Zaitsev/Shutterstock.com]
Crop rotation benefits
As already mentioned, there are many benefits to crop rotation. The following is a list summarising the main benefits.
- Higher yields, and yield stability year after year: Rotating crops will keep individual crops producing at their optimum as they are growing in “fresh” soil each year. The overall harvest yields for your garden will become more consistent on a yearly basis as the crops produce better and the pests and diseases do not accumulate in the same location every season and every year.
- More consistent nutrient usage: When you rotate your crops, you can alternate between heavy feeders with light feeders and moderate feeders. You can also at times leave an area fallow and not plant it, or plant it with cover crops that build up nutrients and which you cultivate back into the soil instead of harvesting. This allows the soil to recover and maintain a more consistent nutrient level, resulting in greater soil fertility.
- Fewer diseases or less severe occurrences: Pests and diseases can often persist in the soil, even over winter. If the same crop is consistently grown in the same area, pests that prefer this crop will amass to levels that the crops cannot tolerate, and harvest yields will suffer. Crop rotation makes it so the species-specific or host-specific pests and diseases will die off or vacate the area in the down years when their host crops are absent.
- Reduction in unwanted plant species: Crop rotation can also help reduce“weeds”, or plants that are out of place. Certain crops do a better job at covering the soil than others, for example, cabbage (Brassica oleracea) and potatoes (Solanum tuberosum) grow thick foliage that covers the soil more completely. This can help to stop some unwanted plant seeds from germinating, thereby stopping them from growing in a certain area for a season.
The main downside to crop rotation only comes about when you have insufficient area to garden. Crop rotation requires adequate space for it to be effective. You need to be able to section off your garden into areas where root systems will not intertwine and space things far enough apart where pests and diseases cannot easily transfer to the different locations.
Dividing your garden into sections helps to keep crop rotation organised and efficient [Photo: Josef Hanus/ Shutterstock.com]
Vegetable crop rotation chart
As was mentioned earlier, crop rotation requires sectioning off your garden space. Creating a crop rotation chart either on paper or electronically will help you keep tabs on which crop is planted where each year. You can develop a 3-year crop rotation chart or a 4-year crop rotation chart depending on which crops you intend to grow. The 4-year plan is more important if you focus one section of your garden on a crop that requires more space, such as alliums or legumes. The 4-year plan can also be useful when including a green manure cover crop in your rotation schedule.
Once you have sectioned off your garden, group your intended crops first by their family, then second by their nutrient consumption level, and third by their space requirements. This will allow you to take advantage of pest and disease reduction as well as nutrient-balancing aspects of crop rotation. Partition your garden plot or allotment off into enough sections to accommodate the crops you wish to grow. This includes flowers and perennial crops like strawberries (Fragaria × ananassa) and rhubarb (Rheum × hybridum). Each year, shift your crops to the next plot over, so that heavy feeders follow legumes, legumes follow light to moderate feeders, and light to moderate feeders follow heavy feeders. There is no one perfect way to rotate your crops, as all gardens are unique. Just do what works best for you and your space! The table below lists some crops and their families from high to low based on how many nutrients they consume.
| Family | Crop | Nutrient consumption |
|---|---|---|
| Composites (Asteraceae) | Lettuce Jerusalem Artichokes Salsify Chicory |
Moderate
Low |
| Umbellifers (Apiaceae) | Carrots Celery Parsnips Fennel |
Moderate |
| Brassicas (Brassicaceae) | Broccoli Cauliflower Brussels sprouts Kale Kohlrabi Swedes Turnips Radishes Mustards |
High
Moderate Low |
| Legumes (Fabaceae) | Bush beans French beans Broad beans Runner beans Peas |
Low |
| Alliums (Amaryllidaceae) | Leeks Garlic Onions |
High Moderate Low |
| Nightshades (Solanaceae) | Tomatoes Potatoes Peppers Aubergines |
High |
| Cucurbits (Cucurbitaceae) | Pumpkins Courgettes Cucumbers Melons |
High |
| Beet family (Amaranthaceae) | Beetroot Chard Spinach |
Moderate |
Tip: Even if you practice intercropping and companion planting, you can still also practise crop rotation. Intercropping and companion planting are very similar. They rely on planting multiple crops in the same area that grow well together and benefit one another. Keep in mind which plants you group together and change their location to a different section each year. Allow three to four years between planting the same groups in the same location.
The goal of crop rotation is healthy soil; healthy soil grows health plants [Photo: TanaCh/ Shutterstock.com]
Crop rotation also works with permaculture systems. Learn more about permaculture in our in-depth article on the subject.