Source: Boucher, D. H. 1986. High-input polyculture: an analysis of resource competition in agriculture. Field Crops Res. 14:105-115.

A mathematical model has been developed to find out whether or not the advantage of polyculture over monoculture increases when high levels of inputs are added. This model provides statistical information as to whether polyculture or monoculture is more sustainable in various situations. The paper begins with a discussion of previous conflicting theories on polyculture. Boucher discusses views of Nicol (from 1935), Kurtz (from 1952), Cunard (from 1976), and Kass (from 1978) that polycultures are adapted to poor soils and low inputs. He then addresses Hutchinson (from 1978), Vandermeer (from 1981), and Willey's (from 1979) theory that polycultures have more of an advantage over monocultures in fertile soils and with high inputs. Boucher points out that all of these theories are based on qualitative assumptions. A mathematical model that could be used to determine how inputs affect the advantage of polyculture over monoculture was not developed by those earlier workers. Boucher derives his mathematical model, basing it on the crop yields (Y), crop prices (P), and inputs (x), for both the monoculture and the polyculture crops. Boucher then puts his model to work, testing it with published research data. His model showed that both increases and decreases can occur in the difference between the polyculture and monoculture yields when high amounts of resources are added. The advantages of polyculture tend to increase with higher inputs, but Boucher concludes that more data are needed to determine the details of the polyculture advantage.

Abstract author: Lawrence Klecha, 18 October 1995.

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