We are all beneficiaries of the farmed crops that keep us fed, but how often do we think about the ways in which they’re produced? For those of us living in towns and cities, somewhat disconnected from farmland, the answer is probably not very often.
Yet the way we grow crops is vital to both our economy and our environment. In the global north, we have spent a century industrialising and optimising the economic output of agriculture but, in recent decades, have begun waking up to the environmental damage these practices have wrought.
One such destructive practice is what’s known as monocropping. Monocropping is when just one crop species is grown continuously on a piece of land over a sequence of seasons. This creates a monoculture.
Benefit and detritment
In the short term, monocropping is very efficient. It enables farmers to focus on growing the most valuable crop available to them, which can be done with less equipment and a narrower set of knowledge and skills. That means less upfront investment and more profit. Ideal, right?
Well, not exactly. The problem with monocropping is that it’s risky and quite shortsighted. In the long term, there are several disadvantages. For the consumer, it can limit the diversity of foods available to them, with fruits, vegetables and grains that could be available instead deemed not profitable enough by monoculture-focused farmers.
But it presents a long-term problem to farmers as well. Maintaining a monoculture across multiple seasons means transferring pests, diseases and weeds from season to season too. This tends to result in a gradual decline in both harvest yields and crop quality over time, as well as eroding soil quality. The long term implications of that can be devastating, turning large swathes of land infertile over time, which take years to recover from.
There’s a reason why nature doesn’t create monocultures.
Monocropping can also result in idle fields during the off season, which means many farmers prefer a system known as sequential cropping. This means continuing to grow one main cash crop, but rotating in another between its most productive seasons. This secondary crop can actually take more time to grow and ideally needs to be quite hardy (able to grow in less productive seasons), unattractive to the other crop’s pests, and able to reintroduce nutrients – particularly nitrogen – to the soil.
But a better solution, certainly from a sustainability perspective (read: not just good for the environment, but good for long-term economic output), is the more historic method that continues to be used in much of the global south. Namely, multicropping.
Types of multiple cropping
Multicropping means growing two or more crop species on the same piece of land – in other words, a polyculture. Generally, these crop species have overlapping growth cycles. But there is a method of multicropping known specifically as intercropping, which involves growing multiple crops on the same land within the same growing seasons.
Multicropping systems are particularly common on small farms where the goal is as much to feed the family or community that works the farm as it is to trade crops outside of it. Such systems depend on locally improved cultivars (also known as landraces), as well as seasonal rainfall and naturally occurring nutrients from the soil, crop residues, and domestic animals.
While this might not be so profitable across a limited number of harvests, in the long run it can be more efficient. Land is never left idle as crops that thrive in different seasons are constantly overlapping, but also interacting, benefitting from the nutrients produced by their neighbouring plants.
Done well – though dependent on which crops can grow on the land and how much market demand there is for them – this can potentially be more profitable that monocropping in the short term too. But it’s also less risky. If one crop fails in a monocropping system, that’s a disaster. A famous example of this happening is the Irish potato famine, where a single water mould (combined with incompetent colonial administration from the British) was able to ravage an entire country that had become economically dependent on just one crop.
In contrast is the practice of Baranaja in the Garhwal Himalaya of India – one of the more extreme forms of multicropping. Baranaja involves sowing 12 or more crops on the same plot of land, including many grains and pulses, which are then harvested at different times to feed communities throughout the year.
Higher functioning agricultural system
Ultimately, multicropping and crop diversity means a higher functioning agricultural system that’s more productive in the long term, protected from crop failure, and somewhat self-regulating, meaning it’s less dependent on inorganic fertilisers and pesticides.
That’s not to say it’s not without disadvantages. Some pests and weeds can thrive in more diverse environments, which is one reason to use intercropping instead. That entails harvesting multiple crops at once, so that pests and weeds can be managed prior to planting another selection of crops.
Another solution is companion planting, which really illustrates what a wonderful system multicropping can be at its best. Companion planting is essentially optimising the combination of cultivated plants in order to make the most valuable crop more productive. A common example of this is growing tomatoes, onions and marigolds together. Not only do they get along quite nicely, but marigolds also repel many of the tomato’s natural pests.
Of course, farmers have to choose the cropping method that works best for them, but it’s worth remembering that industrialised agriculture’s relatively recent economic successes are not sustainable. There are still lessons to be learnt from smaller farmers and traditionally agrarian economies that can benefit not just our environment and food supply, but also their long-term profits.