Division of Soil Resource Studies, National Bureau of Soil Survey and Land Use Planning, Amravati Road, Nagpur, 440 010, Maharashtra
Three benchmark Vertisol pedons pertaining semi-arid (moist), semi-arid (dry) and arid regions of India were studied for the depthwise distribution of smectite in different soil size fractions. Smectite content is more in semi-arid (moist & dry) soils comparing with arid soils and its content increased with depth and in BC horizon it decreased. Smectite dominates the clay fraction of Bss horizons and the depth distribution of smectite indicates illuviation of fine clay smectite in the studied soils.
