Fundamentals of Soil Science (1+1)

Soil

Soil

• As early as 5000BC, the Vedas and Upanishad as well as other Indian literature mentioned soil as synonymous with land – the Mother – supporting and nourishing all life on earth.
• For a laymen it is the dirt and dust on the surface of the earth.
• To the farmer, soil is that portion of the earth’s surface which he can plough and grow crops to provide him with food and fiber for his own needs and that of animals, to the poor man.
• For a mining engineer soil is debris covering the rocks
• For engineers soil is any unconsolidated material removed in excavations and used for filling or provide foundation structure
• Definations:
  

Whitney (1892) : Soil is a nutrient bin which provides all the nutrients required for plant growth.

Hilgard (1892): Soil is more or less loose and friable material in which plants , by means of their roots , find a foothold for nourishment as well as for other conditions of growth.

Dokuchaiev (1900): Father of soil science- Soil as a natural body composed of mineral and organic constituents, having a definite genesis and a distinct nature of its own.

Joffe (1936): Soil is a natural body of mineral and organic constituents differentiated into horizons of variable depth, which differs from the material below in morphology, physical makeup, chemical properties and composition and biological characteristics”.

Jenny (1941): Soil is a naturally occurring body that has been evolved due to combined influence of climate and living organisms acting on parent material as conditioned by relief over a period of time .

Simonson (1957): The soil is three dimensional body having length, breadth and depth which form a continuum over the land surface and differ gradually from place to place.

Soil Science Society of America (1970):
(i) The unconsolidated mineral material on the immediate surface of the earth that serves as a natural medium for the growth of plants
(ii) Soil is the unconsolidated mineral matter on the surface of the earth that has been subjected to and influenced by genetic and environmental factors viz. parent material, climate, macro and microorganisms and topography, all affecting over a period of time and producing a product, that is “SOIL” that differs from the material from which it is derived in physical, chemical, biological and morphological properties and characteristics.