A Bench Mark Soil is a reference point which is adequately characterised in terms of its properties and environmental conditions. The information about Bench Mark Soils can be extended to other soils closely related in classification and geography. The Bench Mark Soils are selected from among the existing and established soils that represent typical range of characters based on Major Land Resource Areas or Agroecological Zones. The Bench Mark soil list helps the research community to focus their investigative efforts on key soils that have the greatest potential for applying new technology across a large area, and also for transferring new technologies to similar soils, thereby optimizing cost-benefit ratios.  The criteria for grouping a soil as Bench Mark Soil, standardised by the United Sates Department of Agriculture are extent, key soils, unique soils, existing data etc.

                  Eighty two Bench Mark soils have been identified in the 27 different Major Land Resource Areas of Kerala for which soil monoliths were collected. A Bench Mark Soil is one that is widely extensive, holds a key position in the soil classification system and is of special significance to farming, engineering or other uses. The basic objective of Bench Mark Soil is to focus attention on extensively occurring soils and their agronomic concepts for wider acceptability of interpretations and for extrapolation of research data. The Bench Mark Soils are selected from among the existing and established soils that represent typical range of soil conditions within the state and having extensive coverage. It is the representative of the most extensive soils in major land resource area or agro ecological zone of the state and/or holding a key position in Soil Taxonomy. The selected soil should have large amount of research data for making transfer of agro technology feasible. Studies of Bench Mark Soils helps in soil correlation, standardization of legends, prediction of soil behaviour, agro technology transfer and planning further research in allied disciplines. District wise GIS maps of bench mark  soils are listed below:

(Source: Department of Soil Survey and Soil Conservation, Kerala)