Introduction

It is widely recognised that agriculture plays a pivotal role in managing and maintaining landscapes around the world. However, it is also commonly accepted that both the expansion and the increasing intensity of modern agricultural practices have had a huge impact on the natural environment. In many parts of the world traditional low-input low-output farming systems remain. In order to understand the effects of intensive farming practices on the environment, we need to comprehend the changes and advances that have taken place in agricultural practices, which have transformed many of the traditional farming systems to a system of intensive monocultures. While the causal agents of environmental degradation (such as the increased use of fertilisers and pesticides) are very well known and documented, it is difficult to separate the influences of agricultural policy and new technology as the underlying drivers.

The traditional integrated low-input low-output system

Before the development and widespread use of artificial fertilisers and pesticides and large-scale irrigation and drainage schemes, crop and livestock production was dependent on the productivity provided by natural environmental conditions. Agricultural production was limited by the availability of soil water; the natural fertility of the soil; and pests, weeds and diseases. The level of inputs available to farmers was low and the level of outputs was correspondingly low. Farmers maintained the fertility of the soil and controlled pests and diseases by using a variety of different farming systems.