…seminar…Barkatullah University Institute of Technologyon Presented by: Shivam Tiwari Mech Engg. III sem.
Soil is the unconsolidated coverWhat on the surface of the earth. Soil is made up of mineral is particles, organic particles, air, and water.soil? Soil is capable of supporting plant growth.
Whatis aSoilProfile?• A soil profile is a view of a cross section of soil.
Functions of agricultural soils • Anchor plant roots • Supply water to plant roots • Provide air for plant roots • Furnish nutrients for plant growth • Release water with low levels of nutrients
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?
RockRock is solid and made of minerals
SandSand is tiny grains of worn down rock. It doesn’t hold water or have many nutrients.
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
CLAY Clay holds water well. It is sticky and can be shaped when it is wet. But, it is very hard when dry.Clay has many nutrients. Clay is used for adobe or brick houses.
HumusHumus is made of leaves, twigs, small animals, or other decayed substances.Humus adds many nutrients to the soil.Humus is in the topsoil.
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
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
Supplying Plant Nutrients Nutrients 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)
Where do plant nutrients come from?• Decaying plant litter• Breakdown of soil minerals• Addition by humans – Commercial fertilizer – Manure – Lime – Other
Recycling plant nutrients
Breakdown of soil minerals Water Acid Zn Ca K Ni Mg Cu
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
Characteristics of the Soil Horizons• 0 Horizon-located on surface, mostly O.M.• A Horizon-Called Topsoil, good amounts of O.M. and minerals.• B Horizon- Known as Subsoil, Less O.M.• C Horizon- Mostly parent material, does little for plant growth.