Polycultures consist of cultivating two or more crops (or animal species) on the same piece of land. Polycultures are often grown in groupings that either complement their nutritional needs or growing habit. Though polycultures have long been practiced in traditional farming systems around the world, the development of farm machinery, synthetic fertilisers and pesticides and a preference for simpler, more intensive systems that lend themselves well to economies of scale led to the displacement of polycultures in many contexts. Polycultures are associated with agroecology, regenerative agriculture and organic farming and are favoured for their role in enhancing biodiversity, improving soil health and reducing the need for chemical inputs.