Planning based on agro-ecological zoning aims at scientific management of regional resources to meet the food, fibre, fodder and fuel wood requirements without adversely affecting the status of natural resources and environment. An attempt has been made to map the agro-ecological units for Vellore district of Tamil Nadu and derive the crop-zone map for the four major crops namely, paddy, sugarcane, groundnut and millets. The basic theory of FAO framework for Land Evaluation was adopted to define the suitability of crops. Land quality details necessary for evaluating the agro-land suitability of crops and for delineating the agroecological units include the terrain, soil and climatic characteristics. Agro-ecological units map was generated by overlaying the agro-edaphic and agroclimatic map layers in GIS. The agro-land suitability map was generated by matching the crop requirement details with the land qualities. The results of the suitability evaluation, when compared with the current land use statistics of these crops showed that area cultivated is less than the area suitable for these crops.
