Polyculture: Letting Nature Do the Work — Contribution from Andrew Flachs

As gardening season comes to an end, many of us are coming to terms with an unwelcome competition for our fruits and vegetables. As much as we love a good tomato or cabbage, there are plenty of creatures who love them even more than we do. The fight against insect and other animal pests is a defining feature of agriculture – animals love our food crops so much that some archaeologists think that the origins of agriculture were as much about eating the animals visiting our gardens as they were about the gardens themselves! Unless you’re a hunter or insectophile, this thought might offer little comfort. A casual search of Amazon or a visit to your local home and garden store offers dozens of chemical solutions to your animal pest needs, including pesticides, traps, and other insect doomsday devices. But as with many problems of modern life, this is something that humans have dealt with for a long time. While chemical solutions are effective for many people dealing with gardening woes, there is another low-tech solution that requires a different approach:  rethinking how we plant our crops.

Much of our modern world is defined by monocultures. Our lawns are kept clear of dandelions or oniongrass; our farms are renowned for their uniform crops and straight lines; our grocery stores sell that food in discrete chunks of color and shape. The political scientist James Scott called this way of interacting with the environment “legibility” – our need to impose order on the natural world – and highlighted our frequent failure to get it right. The problem with these legible orders is that they aren’t very practical in environmental life. That’s because through the processes of evolution and environmental change, plants, animals, and environments have developed ways of working together. Take out those symbiotic elements, and we open ourselves up to a new set of problems.

Consider the agricultural monocrop. A field containing only one species is efficient and useful from a narrow perspective: it is easy to plant, it looks neat and legible, one can spray herbicides that don’t affect the crop, and it is easy to harvest with a machine built to harvest that particular plant. This is easy and efficient in the sense that all the tools can be specialized and all the work happens in one place – just like a factory is efficient for bringing together workers and divisions of labor. But in addition to this being a non-low-tech version of agriculture because it requires so much specific technology, this kind of farming is hard to keep up. Plant the same crop in the same field year after year and the plants ultimately require the same demands on the soil and attract the same pests year after year.  Rotating crops can mitigate some of these effects, but people all over the world use an even more low-tech solution.

By mimicking naturally occurring systems and planting different kinds of crops in a field, polycultures and illegible agricultures solve this problem on their own. When interspersed in the field, mixtures of plants that enrich soil by drawing atmospheric nitrogen down into their roots or drop a heavy volume of nutrient-rich leaves each year ensure that the same compounds are not continually stripped from the soil and obviate the need for chemical fertilizers; a combination of strategically placed plants that attract pest-killing insects and birds, or draw target pests away from valuable plants, can work as effectively as pesticides; agriculture planted in lumps or mounds can take advantage of the natural landscape’s microclimates of water drainage or plant structure as crops reach  up to the sun. This kind of farming usually requires a lot more human labor and plant knowledge because so few of these methods are things you can buy, like a fertilizer or pesticide package. However, this kind of knowledge-intensive polyculture is a foundational part of sustainable design systems like Permaculture and it underlies alternative agricultural work where I do research in India.

In our own backyards, we can apply a few of these methods in practical ways on a small scale. Here are three of the easiest intercrops: strategically placing marigold flowers will repel insects from your tomatoes, nasturtium is an excellent trap plant for aphids, and an earth mound called an herb spiral can take advantage of the different sun and water requirements of your herbs without taking up a lot of space.  These are solutions to common gardening problems that require knowledge and labor, but don’t require new kinds of technology. Instead, we can look to cultural and natural systems around us and take advantage of the best-tested low technology there is.

Andrew Flachs is an environmental anthropologist working to understand alternative farming practices around the world.  He earned his PhD in anthropology at Washington University in St. Louis and currently works in Germany, where he studies biotechnology and organic agriculture in India.  His scientific writing, photography, and writing for National Geographic can be found at: www.andrewflachs.com.  A firm believer in doing too much, Andrew is an avid cyclist, cook, and musician whose work has been featured on the NPR tiny desk concert contest.