The use of models to explore IPM strategies and design pest suppressive landscapes for sustainable agricultural practice

Abstract

In order for agriculture to move from an unsustainable reliance on broad-spectrum chemical pesticides to a more sustainable future, we need make a transition to a 'total system' approach. Agricultural pest problems need to be considered beyond the crop boundary, and we need to understand the role of the landscape matrix for the suppression of pests in crops as well as providing other ecosystem services, such as pollination. We combine field-based survey data with a spatially-explicit simulation model to assess the benefits of integrated pest management strategies at the landscape scale. We explore the features of pest suppressive landscapes for a native insect pest in Australia, the Rutherglen Bug (Nysius vinitor). The model is designed to explore spatially the effects of environmental drivers including temperature, habitat type and habitat quality, on the population dynamics and dispersal of the bug. This drives its landscape pest status for a given season and location. We present scenarios evaluating pest control benefits that are likely to be achieved from managing native remnants by weed removal at multiple spatial scales. Our results indicate that the spatial location of weedy pasture in relation to the crop appears to be highly important in determining the density of N. vinitor within the crop (outweighing the effect of the overall proportion of weedy non-crop habitat in the landscape), and this warrants further exploration. Our approach as illustrated in this paper, using models combined with field data to explore Integrated Pest Management (IPM) strategies and design pest suppressive landscapes, will allow farmers to optimize multiple ecosystem service benefits by i) understanding both the hazards and benefits of non-crop vegetation in the landscape ii) providing a tool to help plan the extent and location of re-vegetation plantings. This work has potential to influence agricultural land use policy in Australia, with further work planned to model the implications of landscape change and non-crop habitat management strategies for multiple ecosystem services.