Some of the best quality farmland has been lost due to the growth of cities. This urban sprawl is mainly caused by new housing developments, but new industry, out of town shopping centres and multi-lane ring roads and by passes all contribute.

One solution is to build within the city in brown-field sites, although these places are not always popular as they have traffic congestion problems and lack of room for expansion. Another is to use a green belt - an area around a city where development is meant to be restricted by law. Such schemes have only had limited success.