1.seminarBarkatullah University Institute of Technologyon Presented by: Shivam Tiwari Mech Engg. III sem.

2. Soil is the unconsolidated coverWhaton the surface of the earth.Soil is made up of mineral is particles, organic particles,air, and water.soil? Soil is capable of supporting plantgrowth. 3. Whatis aSoilProfile? A soil profile is a viewof a cross section of soil. 4. Functions of agricultural soils Anchor plant roots Supply water to plant roots Provide air for plant roots Furnish nutrients for plantgrowth Release water with low levels ofnutrients 5. There are five components of soil: 1. Rock 2. Sand 3. Silt 4. Clay 5. Humus Can you match each type of soil to its picture? 6. RockRock is solid and made of minerals 7. SandSand is tiny grains of worn down rock. It doesnthold water or have many nutrients. 8. SiltSilt is very small, broken pieces of rock. It is larger than clay, but smaller than sand. It is powdery when dry.Sand ------------Silt---------------Clay 9. CLAYClay holds water well. It is sticky and can beshaped when it is wet. But, it is very hardwhen dry.Clay has many nutrients. Clay is used for adobe or brick houses. 10. HumusHumus is made of leaves, twigs, small animals, or other decayed substances.Humus adds many nutrients to the soil.Humus is in the topsoil. 11. TYPES OF SOIL Indian Council of Agricultural Research ( ICAR ) has divided Indian soils into eight major groups :1.Alluvial Soil2.Black Soil3.Red Soil4.Laterite Soil5.Forest Soil6.Desert Soil7.Saline Soil8.Marshy Soil 12. Soil StructureThe arrangement of sand, silt, and clay particles toform larger aggregates. Organic matter is the glue that holds the aggregates together Large pores (spaces) between aggregates are filled with air in a moist soil. Small pores are filled with water in a moist soil. Even smaller pores inside the aggregates (not shown) are also filled with water.1/10 inch 13. Supplying Plant NutrientsNutrients that plants obtain from the soilMacronutrients:Micronutrients:(needed in large amounts)(needed in small amounts) Nitrogen (N) Chlorine (Cl) Phosphorus (P) Cobalt (Co) Potassium (K) Copper (Cu) Calcium (Ca) Iron (Fe) Magnesium (Mg) Manganese (Mn) Sulfur (S) Molybdenum (Mo) Nickel (Ni) Zinc (Zn) 14. Where do plant nutrients comefrom? Decaying plant litter Breakdown of soil minerals Addition by humans Commercial fertilizer Manure Lime Other 15. Recycling plant nutrients 16. Breakdown of soil minerals WaterAcidZnCa K Ni Mg Cu 17. Nutrient additions by humans Commercial fertilizers Nutrients are in a form that is available to plants Dissolve quickly and nutrients go into soil water Lime Dissolves slowly as it neutralizes soil acidity Releases calcium and magnesium Organic nutrient sources Manure, compost, sewage sludge Decay and nutrient release is similar to crop litter 18. Characteristics of the SoilHorizons 0 Horizon-located onsurface, mostly O.M. A Horizon-CalledTopsoil, good amountsof O.M. and minerals. B Horizon- Known asSubsoil, Less O.M. C Horizon- Mostly parentmaterial, does little forplant growth.