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KENDRIYA VIDYALAYA NO.4
NAME-SANVEG DINKARCLASS-10TH “A”
ROLL NO.1032
GUIDED BY:- RUPA MAM
TOPIC
SOIL THE BASIC & MOST IMPORTANT RESOURCE
DIFFERENT SOIL TYPES DEVELOP IN DIFFERENT
CLIMATES.
Soils-4-1
Image: T. Loynachan
TUNDRA SOILS FORM IN ARCTIC ENVIRONMENTS, HAVE A DARK ORGANIC-RICH UPPER LAYER, AND A MINERAL RICH LAYER OVER FROZEN GROUND.
Soils-4-7Images: Travis Hudson, Alaska/Yukon Society of Professional Soil Scientists
ORGANIC SOILS ARE DARK COLORED, RICH IN DECOMPOSED ORGANIC MATTER, AND FORM IN POORLY DRAINED LOWLANDS SUCH AS SWAMPS AND WETLANDS.
Soils-4-5
Images: Bruce Molnia, Soil Classifiers of Michigan
TROPICAL SOILS ARE REDDISH AND IRON-OXIDE RICH, DEPLETED IN NUTRIENTS, AND FORM IN HUMID AND WARM REGIONS.
Soils-4-4Images: National Cooperative Soil Survey, University of Nebraska
FOREST SOILS HAVE A LIGHT GRAY UPPER HORIZON, A HORIZON RICH IN ALUMINUM AND/OR IRON, AND FORM IN WARM TO COOL HUMID REGIONS WHERE CONIFEROUS FORESTS GROW.
Soils-4-3Image: Bruce Molnia
Image: Soil Classifiers of Michigan
PRAIRIE SOILS HAVE A DARK SURFACE LAYER (HORIZON), ARE RICH IN MINERALS, AND FORM IN GRASSLANDS WIDESPREAD ACROSS EARTH’S MIDDLE LATITUDES.
Soils-4-2
Images: NRCS
Where does soil come from?
•Rocks•Minerals
•Organic Matter
oA
E
B
C
R
TOP SOIL
SUBSOIL
Sagebrush-Cold Desert
WHAT ARE THE MAIN COMPONENTS OF SOIL?
Mineral Matter Air
Water Organic Matter
SOIL COMPONENTSidealized soil
SOIL SOLIDS
WATER FILLED PORES
AIR FILLED PORES
50 %
25 %
25%
Soil Components (volume basis)
Note: clays are microscopic in size !
Soil separate particle diameter (mm)____________________________
Sand . . . . . . . . . 2.0 - 0.05
Silt . . . . . . . . . . 0.05 - 0.002
Clay . . . . . . . . . . <0.002
SAND
SILT CLAY
Clay mineralsphotographedwith an electronMicroscope.
Note: they are plateor flake like andare stacked on topof each other.
They are electricallycharged and act likemagnets that attractand hold plantnutrients.
What causes soil erosion?
WaterWind
No Vegetation
For agriculture soil is important
What are the FACTORSthat make SOIL?
TIME1000’S TO 10,000’S OF YEARS
LAY OF THE LANDTOPOGRAPHY
LIVING ORGANISMSANIMALS AND PLANTS
CLIMATEHOT/COLD, WIND/RAIN
PARENT MATERIALROCKS AND MINERALS
Physical land features
How can we manage soil??Soil Management, the basis of all scientific
agriculture, which involves six essential practices:
proper tillage; maintenance of a proper supply of organic
matter in the soil; maintenance of a proper nutrient supply; control of soil pollution; maintenance of the correct soil acidity; and control of erosion.
WHAT ARE SOME PERACTICES OF SOIL
CONSERVATION?Terracing
Strip CroppingContour Plowing
TillingWind Breaks
Ground Covers
Contour Farming