Soil

Soil

Alluvial soilRed soilBlack soilLateritic soilMountainous soilDesert soilSaline alkaline soilMangrove soil

Soils of India

Covers 42% of Indian soilDeposition of riversMost fertileRich in organic material, micro-nutrients, well-drained Lacks PhosphorusAlluvial soilNorthern Plains, east coast, GJ except KathiawarFrom East to west:Fertility + Rainfall decreaseBut Productivity + technological advancement increaseAlluvial soil

East India: high potential for 2nd Green revolution Provide Irrigation + modern agro-practiceRJ plains: vulnerable to desertification, seepage from canal - salinityAlluvial soil

Covers 25% of Indian soil areaMost wide-spreadFormed due to erosion of granite and Gneissic rocks having iron and NickelBest-drained soil-least susceptible to water-logging

Red soilRich in lime, phosphate, iron, Potash, humusBut lack in Nitrogen and PhosphorusIt can support maximum crop-diversityImportant for food security and nutrition balanceRed Soil

But most vulnerable to soil-erosionArid regions drought prone= povertyLand fallowingBrick-making loss of top soil

Red SoilPrelims2010Q. When you travel certain parts of India, you will notice red soil. What is the main reason for this colour?Abundance of MagnesiumAccumulated humusPresence of ferric oxideAbundance of phosphate

Ans. C)UPSCQuestion

Covers 15% of Indian soilWeathering of lava rocks of Deccan plateauRich in Ferro-magnesium-silicate, lime and potashLack Nitrogen and Phosphorus

Black soil

Unique property:High clay contentCracks when dry and sticky when wetCracks allow air to reach into depthHigh water retentivity: good for cotton cultivationBlack SoilAreas:MH plateau, Kathiawar, Vindhyan, Kaimur hillsNorthern part KN uplands Black Soil

SoilPosseslacksAlluvial SoilNitrogen, Potash, humusPoor in PhosphorusBlack soilPotash and HumusPoor in Nitrogen and PhosphorusRed soilPotashN, P and humusLaterite soilPotash and Iron in excessN, P and CalciumArid soilHigh CalciumN, humusSalineSodium, Potassium in excessNMinerals in Indian soilCovers 4.5% areasAlternate wet-dry weatherLaterite = brick

Latosol (lateritic soil)

Leaching of silica iron remain in the top layerThick iron pans PetlandsAcidic soilQuickly eroded on deforestation, mining and plantation

Latosol (lateritic soil)

Not suitable agricultureBut suitable for sp. Crops like Tapioca and cashew nutsRich in iron support tea, coffee and rubber plantation with fertilizers

Lateritic soil: agriculture

Rich in BauxiteEastern Ghats, Telangana and KN plateau

Latosol (lateritic soil)Prelims2013Q. Which of the following statement regarding laterite soil of India are correct?They are red in colourThey are rich in nitrogen and PotashThey are well developed in RJ and UPTapioca and Cashew nuts grow well on these soilUPSCQuestionPrelims20131,2 and 32,3 and 41 and 42 and 3

Ans. C)UPSCQuestion

Very thin layer of soilUnder-developed soil horizonSoil at steep gradient cannot support agricultureCan support grassed of scrubsMountainous soil

Podzolic soilUnder cold humid climateLeaching of iron silica remain at top soilNot good for agriculture but good for forestry - lumbering

Mountainous soilChelation = Leaves of coniferous trees covered with cheating agent hard to degradeCold climate slow bacterial processHumus content is high

Mountainous soil

Sandy, loose and friable soilCoarse texture, low water holding capacityLow nutrient, low fertilityCannot support agriculture

Desert Soil

Indian desert soil is uniqueIts made up of alluvium, fine loessic depositsGood in micro-nutrientsSupport agriculture under irrigationVulnerable to salinity and desertification

Desert soil

Along tidal region of coastal areasGleying processSwampy-peaty soilBluish-green colour due to sulphideNot suitable for agriculture but support mangroves

Mangrove soilSoil problem areasBad drainage in arid areasOver-irrigationCanal areasWest RJ, PN-HN, terai belt, Deccan region

Saline Alkaline soil

2 stages:Calcification: moderate aridity conditionCalcium salts in upper layerSaline soil: extreme arid conditionSodium and Potassium salts in upper layerSaline Alkaline soilSoil

Total geo area = 328 ml haTotal reported area = 305 ml haIndia 17% of world population on 2.4% of land9 different ways of land use in India (Dept. Land resource)

Land use pattern in IndiaLand typeUsage in % of total reported areaForest23% -25%Net sown area46%Land not available for agricultureDevelopmental landWasteland15%Fallow land12.5%Pasture land3.5%Trees and grooves