Major Soil Types and Classification

Abstract

The chapter is an effort to understand soil types of India and further classifying them since time immemorial from the start of civilization itself. Derived from a wide range of rocks and minerals, a large variety of soils exist in the Indian subcontinent. Soil-forming factors like climate, vegetation and topography acting for varying periods on a range of geological formations and parent materials have given rise to different kinds of soil. The National Bureau of Soil Survey and Land Use Planning, Nagpur, as a premier soil survey institute, has been consistently using benchmark soil series to understand the rationale of the soil taxonomy, keeping in view the soil genesis from different rock systems under various physiographic locations in tropical India. The NBSS & LUP has developed a database on soils with field and laboratory studies over the last 50 years. This has generated maps and soil information at different scales, showing area and distribution of various soil groups in different climatic zones or agro-ecological sub-regions. The 1:250,000 scale map shows a threshold soil variation index of 4-5 and 10-25 soil families per m ha for alluvial plains and black soil regions, respectively. Progress in basic and fundamental research in Indian soils has been reviewed in terms of soils and their formation related to various soil-forming processes. More than 50 years ago, the US soil taxonomy was adopted in India. However, India should have its own system of soil classification at least for the purpose of correlation with international and universal systems.