LAND EVALUATION MODELING TO ASSESS THE EFFECTS OF CLIMATE-CHANGE ON WINTER-WHEAT POTENTIAL IN ENGLAND AND WALES

The effects of climate change on crop suitability in England and Wales were estimated by systematically adjusting agroclimatic data inputs to a land evaluation model. Mean temperature rises of 1 and 2 degrees C increased drought risk and reduced the length of time when soil was at held capacity over-winter by raising potential evapotranspiration. In eastern England, this change had a detrimental effect on the potential for cultivating winter wheat because of drought stress. In northern and western England and Wales, drier conditions promoted greater opportunities for soil tillage, especially when temperature rises were associated with decreased precipitation. The effect of increased temperature was offset by increased precipitation. The magnitude of the drought stress and length of field capacity periods are similar to current mean conditions when a +1 degrees C temperature change is coupled with a 10% increase in precipitation. This demonstrates that winter wheat suitability in England and Wales is affected more by changes in precipitation than by changes in temperature. The local limitations of soils and relief notwithstanding, it appears that the northern and western areas of England and Wales are most likely to gain from a warmer, drier climate.