AGROCLIMATIC ZONES FOR DRYLAND WINTER-WHEAT PRODUCING AREAS OF IDAHO,WASHINGTON, AND OREGON

There is a need to develop a series of "zones" to facilitate technolog y transfer within the Intermountain Northwest. Six agroclimatic zones have been delineated based on three climatic and soil parameters impor tant in growing winter wheat: soil depth, mean annual precipitation, a nd cumulative growing degree from 1 January through 31 May. Thus each zone, regardless of the state in which it is located, has similar soil and climatic conditions. There are uncultivated areas within each zon e that are not identified but if farmed would be farmed like other par ts of the same zone. The zones provide a common basis for identifying areas where successful exchange of practices, experience, and knowledg e between and among producers, researchers, extension, and Soil Conser vation Service personnel will most likely occur. Management decisions that produce desired results in one zone in one zone in one state will probably succeed in that same zone in any other state. Conservation p ractices and erosion control techniques should be similar within but n ot between zones.