An Assessment of Soil Properties under Different Landuse Types of the Kallada River Basin, Kerala, India

Abstract

A thin layer of soil covers most of the earth's land surface. This layer varying from a few centimeters to 2 or 3 meters in thickness might appear insignificant relative to the bulk of the earth. On the basis of morphological features and physico chemical properties, the soils of the Kallada basin can be classified into broad six groups (1) Coastal alluviam 2) Riverine alluviam 3) Brown hydromorphic 4) Greyish Onattukara soil 5) Laterite soil and 6)Forest loam (GSI Map). Twenty four soil profiles were collected from the Kallada river basin for analysis, whose 12 profiles are in one cluster distributed adjoining the Western Ghats crest. As many as 12 profiles were under forest, three under grasslands, three under teak plantations, two under mixed tree crops, two under tea plantation and one each from eucalyptus and rubber plantations. Soil is a rich but fragile ecosystem. It is a three-phase system, composed of solid, liquid and gaseous phases.  In most soils, the solid phase makes up the vast majority of the soil mass, and over half of its volume.  It consists of mineral matter derived from the weathering of rocks and organic matter from the decomposition of plants and animals.  The liquid phase is composed predominantly of water, enriched with dissolved solids, the gaseous phase of air, enriched with carbon dioxide from the respiration of soil animals and plant roots. Physical properties of the soil are determined by the character of solid particles and the way in which they are packed together.