Rahul Bajpai M.tech Remote sensing & GIS RSACUP
- 1. ““... the Latin name for man, homo, derived from humus, the stuff of life in the soil.” --- Dr. Daniel Hillel By:Rahul Bajpai
- 2. . TOPICS •Introduction to Soil •Soil Genesis •Types of Soil •Properties of Soil •Soil Survey •Soil Mapping And Classification •Soil Plant Relationship •Soil Erosion •Spectral Response •Soil Management
- 3. Introduction To Soil Traditional definition: Material which nourishes and supports growing plants; includes minerals, humus, water and air. Geologic definition: Loose surface of the earth as distinguished from solid bedrock. Civil Engineering: Soil is the earth material that can be disaggregated in water by gentle agitation. Agronomy definition: Soil consists of the thin layers of the earth’s crust formed by surface weathering that are able to support plant life.
- 4. Components of Soil The percentage of composition of soil may vary with the variety of soil
- 5. Soil Forming Processes Decomposition Translocation Leaching SOIL PROCESSES Weathering
- 6. parent rock Weathering breaks the rock into smaller and smaller pieces soil Freezing and thawing of water Wind with sand Running water Heat and cold Ice Physical Weathering Chemical Weathering Acids Water sand silt clay
- 9. A soil with small soil peds or crumbs and high porosity leading to free drainage and active leaching Leaching
- 10. Soil Profile A series of horizontal layers of different chemical composition, physical properties, particle size, water content and amount of organic matter. Horizon Each recognizable layer of the profile.
- 12. O. It's about an inch thick and is made up of dead plants, animals and some humus A. The A horizon called topsoil is made up of humus (decomposed organic matter) mixed with mineral materials. E. This layer, between the A and B Horizons is light in color and made up mostly of sand and silt. B. It contains clay and mineral (such as iron, aluminum oxides, and calcium carbonate). C. consists of broken-up bedrock that is only slightly weathered . R. Layer R is the unweathered rock (bedrock) layer that is beneath all the other layers.
- 13. • Alluvial soils •Black soils •Red soils •Laterite soils •Desert soils •Mountain soils •Saline and Alkaline soils Major types of Soil according to Indian Council of Agricultural Research (ICAR). Types of Soil
- 14. ALLUVIAL SOIL • Formed by deposition of alluvium by rivers. • Contribute greatly in agricultural development. •Light to dark in colour. • Rich in Potash & Humus. • Poor in Phosphorous and Nitrogen. • Highly fertile, good for all crops (kharif & rabi). •Crops: Rice, Wheat, Sugarcane, Cotton, Jute. • Areas: •Punjab, Haryana, U.P, Bihar, W.B, Assam, Parts of Orissa, delta regions of S.India
- 15. BLACK SOIL •.Also known as Regur or Black Cotton soil. • Dark grey to Black in colour. •High clay content. • Highly moist retentive. • Highly suitable for cotton. • Rich in iron, lime, calcium, Magnesium, carbonates, and alumina. •Poor in Phosphorous, Nitrogen and Organic matter. • Areas: Deccan Trap which includes: Maharastra, M.P, Parts of A.P, Karnataka, Parts of T.N and Rajasthan. •Crops: Cotton, Sugarcane, Groundnut, Millets, Rice, Wheat, Oilseeds.
- 16. RED SOIL • Formed due to weathering of old crystalline rocks. • More sandy and less clayey. • Rich in iron, small amount of Humus. • Poor in phosphorus, nitrogen and lime. • Slightly acidic and do not retain moisture. •Area : Tamil Nadu, Southern Karnataka, parts of Madhya Pradesh, Maharashtra, West Bengal, Eastern Rajasthan, North eastern States. • Crops : Ragi, Groundnut, millet, Tobacco, Potato, Rice, Wheat, Sugarcane.
- 17. 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 is know as Laterite. • Brown to Yellowish colour. •Becomes hard when exposed to atmosphere. •Used as building material. •Rich in Iron Poor in Lime, Potash, & Magnesium. •Areas: Parts of Assam, Karnataka, T.N, A.P, M.P, Kerala. • Crops: Tea, Coffee, Cashew, Rubber and Coconut.
- 18. DESERT SOIL •Contains soluble salts. • Originated by Mechanical disintegration & wind deposit. • Porous and coarse. • 90% sand & 5% clay. • Rich in Nitrates & Phosphates. • Poor in Nitrogen & Humus. •Friable, sandy & low moist content. •Areas: Arid and Semi arid regions of Rajasthan, Haryana, Punjab, Gujarat. •Crops: Drought resistant crops like millets and barley.
- 19. MOUNTAIN SOIL •Found in hill slopes. • Formed by deposition of organic matter from forest. •Rich in humus. •Poor in Potash and Lime. •Areas: Assam, Kashmir, Sikkim & Arunachal Pradesh. • Crops: Tea, Coffee, Spices & Tropical Fruits.
- 20. SALINE & ALKALINE SOIL •Contains salts like Sodium, Magnesium, Calcium. •Infertile, unfit for cultivation. •Sandy to loamy in texture. •Areas: Parts of Gujarat, Rajasthan, Punjab, Haryana, U.P & Maharashtra.
- 21. Properties of Soil Soil Physical properties •Soil texture •Soil Colour •Soil Structure •Soil Porosity Chemical Properties •Soil pH •Cation exchange capacity (CEC) •Nutrient Availability
- 22. Physical properties Soil Texture Soil Separates particle size groups of sand, silt, and clay Soil Colour White colors commonly salts or lime deposits are present Mottles (rust colors) – soil may have periods of inadequate aeration Gleying (bluish, grayish, greenish) – sub soils, prolonged periods of water logging Darker colors – higher levels of organic matter
- 23. Soil Structure A. Granular B. Blocky C. Prismatic or Columnar D. Platy E. Structure less(Single grain)
- 24. • portion of the soil not occupied by mineral or organic solids Often referred to as the soil matrix •Typically occupied by: air, water, living roots •Irregular shape, size, & direction to pores Soil Porosity
- 25. Chemical Properties Soil pH •This gives a measure of the acidity or basicity of a soil. • 0-7 = acidic; 7-14 = basic. •Acidity is measured by determining the concentration of Hydrogen (H+) ions in the soil. •Higher concentration of H+ ions = high acidity, higher concentration of OH- ions = high basicity. •In general, the ideal pH for plant growth is about 5.5 in organic soils and about 6.5 in mineral soils.
- 26. Cation Exchange capacity The total number of cations a soil can hold or its total negative charge is the soil’s cation exchange capacity Most commonly held cations – Ca, K, Mg, H, Na, Al, NH4
- 27. Nutrients Availability • The primary nutrients are Nitrogen , phosphorus and Potassium • The intermediate nutrients are Sulfur,Magnisium and calcium.
- 28. SOIL EROSION • Removal of top soil by different agents. CAUSES •Deforestation • Overgrazing. •Faulty method of Agriculture. •Erosion by rivers. • Removal of top soil (for bricks, pots, tiles etc) •Shifting cultivation.
- 29. Types of Erosion Wind Erosion Water Erosion Types of Erosion are based on the agents of erosion
- 30. Soil surveys are the primary references available to help land managers determine the potentials and limitations of the soils. Soil surveys are a compilation of maps and interpretive data. oil Survey Purpose of a Soil Survey Soil Survey • Determine characteristics of the soils • Classify the soils according to a standard system of classification, • Plot boundaries of the soils on a map, and • Make predictions about the behavior and best management of the soils (Interpretations).
- 31. Some of the applications of soil survey are given below. •Sediment Yield Prediction •Soil Erosion Modeling •Soil Quality •Crop Suitability •Hydrology • Global Change and Monitoring •Soil and Water Conservation • Ecological Model Land Use •Environmental Quality •Watershed management
- 32. Soil Mapping Why would we want to map soils? Communication of geographic information Tools for land management and planning Steps in mapping the soil of a given area 1. Define the scale and level of detail that is required. 2. Study existing information regarding the soil, geology, topography, vegetation of the area. 3. Define soil units to be mapped. 4. Compile information about the nature of each soil. 5. Mark boundaries of where each soil unit occurs.
- 34. Class I Soils Can be used continuously for intensive crop production good farming practices Class II Soils More limitations than Class I land for crop production 2-5% slope is main difference Class III Soils Severe limitations Requires more special conservation practices than Class II to keep it continually productive Can have shallow soil Slopes 6-10% Shallow water tables
- 35. Class IV Severe limitations for cropping use Greater intensity of conservation practices for cultivated crops that Class III Recommend permanent crops (e.g. pastures) Slope 12-18% Class V Boulders, wetness, problems impractical to correct Not necessarily erosion risk Can’t be cultivated Use for pasture, range, woodland, wildlife habitat Class VI Slope 18-30% Same limitations as Class V soils, except more need for sustainable management practices
- 36. Class VIII Very severe limitations Steep slopes, rock lands, swamps, etc. Can only be used for wildlife, recreation, watersheds, aesthetic appreciation Class VII Severe limitations Extreme care to protect the soil Even using grazing, wildlife, timber Slope >30%
- 37. A. Anchorage – soil acts to provide a firm support as roots grow throughout the soil. B. Water – soil provides nearly all of the water used by plants. Water is absorbed through the plants’ roots. C. Oxygen – nearly all organisms need oxygen. Roots don’t have ample supplies, so they need good soil aeration to allow gas exchange. D. Nutrients – of the 16 nutrients considered to be essential for plant growth, 13 are obtained from the soil. Root hairs absorb the nutrients dissolved in soil water. Soil - Plant Relationship
- 38. Spectral Signature of Soil
- 39. Soil Management •Reduced Erosion •Balanced pH •Reduced Leaching •Increased Nutrient •Organic Manures Increased productivity
- 40. THANK YOU