IMPLICATIONS OF A SIMPLE COMPETITION MODEL FOR THE STABILITY OF AN INTERCROPPING SYSTEM

It is a common view that intercropping systems of agricultural crops p roduce more stable yields than do systems in which the same crops are grown in monoculture. This paper discusses a modelling approach which has been used to support the notion that whether or not intercropping is more stable than monoculture depends on the mode of interaction amo ng crops, i.e. whether two different crops suppress or enhance each ot her. It is shown here that this notion is not supported by the model u sed. We conclude that the relative merits of the two cropping systems depend on the proportion of land allocated to each crop rather than on the mode of interaction. The model suggests that if the optimum alloc ation of land is considered, both systems will be equally stable.