BLACK SOIL Also known as Regur or Black Cottonsoil. Dark grey to Black in color. High claycontent. Highly moist retentive. Develops cracksin summer. Covers 5.4 lakh sq. km. Highly suitablefor cotton. Rich in iron, lime,calcium,Magnesium,carbonates, and alumina.
RED SOIL Formed dueto weathering of oldcrystalline rocks.More sandy and lessclayey. Rich in iron,small amount ofHumus. Poor inphosphorus, nitrogenand lime. Slightlyacidic and do notretain moisture. 3.5lakhs sq.km area.Porous and Friable.
LATERITE SOIL Latin word meaning brick. Formed under high temperature and rainfall with wet and dry spell. Silica is leached due to high rainfall.Remnants of iron and aluminum oxides left behind isknow as Laterite. Brown to Yellowish color. Becomeshard when exposed to atmosphere. Used as buildingmaterial.
MOUNTAIN SOIL Found in hill slopes. Formed bydeposition of organic matter from forest. Rich inhumus. Poor in Potash and Lime. Areas: Assam,Kashmir, Sikkim & Arunachal Pradesh. Crops: Tea,Coffee, Spices & Tropical Fruits.
SALINE & ALKALINE SOIL Contains saltslike Sodium, Magnesium, Calcium.Infertile, unfit for cultivation. Sandy toloamy in texture. Areas: Parts of Gujarat,Rajasthan, Punjab, Haryana, U.P &Maharashtra.
PEATY AND MARSHY SOIL Occur in Humid region.Formed by accumulation of organic matter.Black in colour. Highly acidic and heavy. Areas:Kottayam & Alleppey in Kerala, Coastal Orissa,Sundarbans of W.B
A sticky soil, such asclay or silt; its shearstrength equals abouthalf its unconfinedcompressivestrength.Soil in which theabsorbed water andpartical attraction actsuch that it deformsplastically at differentwater Contents areknown as Cohesive soilsor clays. These soilspossess higher plasticity. e.g. clays & plastic silt.
Residual soils are those that remain at the place oftheir formation as result of the weathering of theparent rocks. The depth of residual soils dependsprimarily on climatic conditions and the time ofespouser. In temperate zones residual soils arecommonly stiff and stable. An importantcharacteristics of residual soil is that the sizes ofgrains are indefinite.
ALLUVIAL soil is formed when a soil-carrying stream gradually loses its carryingcapacity with decreasing velocity. In slowingdown, a river does not have sufficient power to keep the largeparticles of soil suspended; these particles settle to the riverbed. Furtherdecrease in velocity causes smaller particles to settle. These particlesare deposited, finally, at the mouth of the river, where they form DELTASof fine-grained soil.
MARINE soil is formed from materials carried into theseas by streams and by material eroded from thebeaches by the tidal action of thewaves. Part of the material is carried out anddeposited in deep water; part is heaped upon thebeaches along the coast
A type of soilthat istransportedfrom one placeto another bythe wind.e.gsanddunes,loess.
Loam is soil comp osed of sand, silt, and clay in relatively even concentration (about 40-40-20% concentration respectively). Lo am soils generally contain more nutrientsand humus than sandy soils, have better infiltrationand drainage than silty soils, and are easierto till than clay soils. Loams are gritty, moist, andretain water easily.
Clay is a naturally occurring aluminium silicate composed primarily of fine- grained minerals. Clay deposits are mostly composed of clay minerals, a subtype ofphyllosilicate minerals, which impart plasticity andharden when fired or dried; they also may containvariable amounts of water trapped in the mineralstructure bypolar attraction. Organic materials whichdo not impart plasticity may also be a part of claydeposits.
Glaciers carry with them soils varying insize from fine grained to huge boulder. Soilget mixed with the ice and aretransported far away from their originalposition. Drift is a general term used for thedeposits made by glaciers