Gardeners Can Learn A Lot From Intercropping, The Practice Of Growing Two Or More Crops Together, Practiced By Some UK Farmers Seeking To Reduce Reliance On Chemicals And Potentially Boost Yields.
Table of Contents
This article explores the benefits and challenges of intercropping, addressing some frequently asked questions from a UK farming AND gardening perspective.
Why is Intercropping?
Intercropping is a form of polyculture where two, or more, crops are grown together to produce better crops. An example many gardeners read about is the Three Sisters cropping of maize, cucurbits and legumes. Farmers and gardeners have undertaken these forms of mixed cropping for thousands of years. Crops may be mixed together or grown in alternate rows.
The advantages today are many and are listed below.
Reduced chemical use: Intercropping can help suppress weeds and diseases, potentially reducing the need for herbicides and pesticides.
Improved yields: While the yield of each individual crop might not increase, the total yield per unit area often rises when combining the outputs of both crops.
Financial benefits: In England the Sustainable Farming Incentive offers a payment for companion cropping, making intercropping financially more attractive.
What Is Temporal Intercropping?
Temporal intercropping uses the practice of sowing a fast-growing crop with a slow-growing crop, so that the fast-growing crop is harvested before the slow-growing crop starts to mature. A gardening example would be where we use radish as row markers for slower growing crops such as carrots. The radish crop vey quickly and can be harvested leaving the carrots to come later.
Orchards can also use a form of temporal intercropping. Grass between the trees can be harvested by grazing livestock before the crop of fruit is ready for harvest.
And if you think laterally the grazing of grass between solar panels in fields provides grazing and a “crop” of energy. though whether this is true temporal intercropping is open to debate. I would answer by saying, does it matter if you get two “crops” from one piece of land?
The History Of Intercropping
Intercropping is still used today in countries like Ethiopia, Eritrea, and Georgia.
In medieval England, farmers grew oats and barley together, called “dredge corn,” for livestock feed. Similarly, French peasants mixed wheat and rye for “pain de méteil” or mixed grain bread. However, the ease of harvesting and changing market demands led to the dominance of single-crop fields.
Dredge Corn wasn’t just medieval farming practice. It was discussed in parliament quite a lot over the years, it was that important. There was a long debate about not in 1917 and in 1949 The Dredge Corn (Great Britain) Order, 1949 was order of the day.
What are the challenges?
Selecting crops: Choosing compatible species that mature around the same time is crucial. Trials this year showed peas and barley performed well together, while beans and oats had issues due to differing harvest times.
Harvesting: Combining different crops like small grains and larger beans requires careful combine setup. The crops can be sold separately or as a combined product, particularly useful for animal feed.
Separation: Separating crops post-harvest is an additional step, dependent on size differences. Existing farm cleaners might require adjustments for proper separation.
Intercropping Yields
Intercropping often produces higher yields, for reasons I will discuss later. And this is a fact acknowledged and recorded in many paces as the next quotation from Hansard details.
Sir John Spears asked the President of the Board of Agriculture if he is aware that much dredge corn is grown in the South of England, that much larger yields are procured than is the case with any other grain, while the straw is more valuable for fodder, and the grain good for cattle and human consumption, if necessary; and will he say what proportion of the quota of corn to be grown on farms can be devoted to dredge corn this year?
Sir John Spears
Of course it isn’t just about dredge corn. The example I gave earlier of radish being grown with carrots is another example. A good crop of both veg are possible if grown with attention to detail.
How Does Intercropping Affect Pests And Diseases?
Reduced pest problems: The diversity of crops makes it harder for pests and diseases to spread quickly. Trials revealed intercropped beans suffered less bruchid beetle damage compared to monocrops.
Healthier soil: Intercropping can lead to healthier soil, potentially making plants more resilient to pests and diseases.
Does intercropping reduce fertiliser use?
Legumes as nitrogen fixers: Legumes like beans can fix their own nitrogen, reducing the need for artificial fertilisers. Trials showed higher soil nitrogen reserves following cereals grown with beans.
Reduced nitrogen leaching: Intercropping with legumes, such as peas and beans, may decrease nitrate leaching, and water pollution.
Lessons for Gardeners from Intercropping
Here are some lessons gardeners can draw from the above information on intercropping:
Plant Selection and Timing
Choose compatible crops: Select plants that have similar growth rates and harvest times.
Consider plant height and spacing: Taller plants can shade shorter ones, affecting growth and yield. Therefore put taller plants at the back of a mixed cropped area.
Stagger planting: Planting different crops at different times can extend the harvest season and reduce pest and disease pressure.
Soil Health and Fertility
Legumes as nitrogen fixers: Incorporate legumes into your garden to improve soil fertility.
Diverse plantings: A variety of plants can attract beneficial insects and improve soil structure.
Natural pest control: Intercropping can attract beneficial insects that prey on pests.
Reduced disease pressure: Diverse plantings can dilute the spread of diseases.
Resistant varieties: Choose disease-resistant varieties to further reduce the need for chemical treatments.
Water Conservation
Efficient water use: Intercropping can help conserve water by creating a microclimate that reduces evaporation.
Mulching: Mulching can help retain soil moisture and further reduce the need for frequent watering.
Practical Tips for Home Gardeners
Here are a few other techniques that are vaguely related to intercropping.
Companion planting: I have mixed feelings on companion planting, But, where practiced it sometimes works. The Three Sisters is one such example. And tagetes can be used to reduce pest pressure on some crops.
Succession planting: Plant crops in succession to maximise space and harvest time. Ideally grow polycultures and plant up spaces as soon as harvesting gaps appear.
Vertical gardening: Utilise vertical space to grow more plants in a smaller area.
Experimentation: Don’t be afraid to try different combinations and learn from your experiences.
put seed potatoes in tubs in unheated green house in november 30th covered in 2 layers of fleece 3 potatoesin each tub all taken know 10 ins tall all well so far
put seed potatoes in tubs in unheated green house in november 30th covered in 2 layers of fleece 3 potatoesin each tub all taken know 10 ins tall all well so far