The role of heterogeneous agricultural landscapes in the suppression of pest species following random walk dispersal patterns

The contribution of a heterogeneous agricultural landscape (in terms of field layouts of diversified crop ages) towards pest suppression is considered in this study. The population dynamics of a pest species is modelled for a number of different mosaic configurations of differently aged agricultural crops across a spatial domain, where the harvesting of these fields occurs at different points in time. A reaction-diffusion model (with constant diffusion coefficients) of the pest species' growth and dispersal within a temporally variable and spatially heterogeneous environment is utilised to perform simulations. The primary objective is to establish whether or not there exist certain field configurations of differently aged crops in which average infestation levels are a minimum. It is found that more diversified field configurations (in terms of crop age) with the total length of boundaries shared between differently aged crops at a minimum, yield lower average infestation levels.