It might feel counterintuitive, but the more varieties of vegetables, plants, and insects that are included in a garden, the less vulnerable any single crop becomes. Mans Lanting of ETC Foundation India wrote in LEISA Magazine in 2007 that the best method of approaching pest control is to learn to live in harmony with pests instead of trying to fight them. By harnessing the natural state of vegetation and pests, a farmer can create “a system in which no component can easily dominate” and in which soil and crop quality is greatly improved.
By mimicking the diversity that takes place in nature, farmers can create a garden that relies on natural systems to provide nutrients as well as pest and disease control. (Bernard Pollack)
In other words, the tendency for traditional farming to give preference to specific crops, to plant in clean rows, to weed out any invasive plants, and to use chemicals to prevent pests and disease is actually creating a need for these pesticides and fertilizers. Soil fertility decreases when crops are harvested, and growing a single crop means that the soil is further stripped of nutrients with each season, requiring the use of inputs that, according to Lanting, lead to an imbalance in plant nutrition and increase vulnerability to pests and diseases. This introduces the need for pesticides, which cost more money and create toxic runoff that can damage the local environment.
The result is a self-perpetuating war against infertile soil and a burgeoning pest population.
Instead, Lanting recommends taking an alternative approach, mimicking the diversity that takes place in nature and creating a garden that relies on natural systems to provide nutrients as well as pest and disease control.
Farm biodiversity can be improved by integrating border crops, trees, and animals. Farmers can also include trap crops—crops that attract insects away from the main crop—which include Indian mustard, sunflower, marigold, soybeans, and French beans, as well as crops that promote insect predators such as pulses for beetles, okra for lace wing, and coriander, sorghum, and maize for trichogramma (small wasps). Visual barriers can be used to help “hide” crops from pests. The diamond backed moth, for example, has to be able to see cabbage in order to find it—and destroy it before a harvest.
Nourishing the Planet saw some of these techniques being implemented at Enaleni Farm, a demonstration farm run by Richard Haigh in Durban, South Africa. Haigh cultivates traditional maize varieties that are resistant to drought, climate change, and disease, and he practices push-pull agriculture, which uses alternating intercropping of plants that repel pests with ones that attract pests in order to increase yields. He also applies animal manure and compost for fertilizer. Haigh likes to say that his farm isn’t organic, but rather an example of how agro-ecological methods can work. (See Valuing What They Already Have)
Using these methods, a farmer will have a garden with at least 10 crops, creating an ecosystem that resembles one found in nature. The soil is more fertile, and the insects and diseases are distracted and preyed upon so that their impact is less concentrated. In a sense, a farmer needs to let the garden get wild in order to protect it from the wild.
To read more about chemical-free farming practices see: In Botswana, Cultivating an Interest in Agriculture and Wildlife Conservation, Malawi’s Real Miracle, Emphasizing Malawi’s Indigenous Vegetables as Crops, and Finding ‘Abundance’ in What is Local.