Soil is a mixture of organic matter, minerals, gases, and organisms that together support life. Soil formation involves weathering and soil development through biological and chemical processes. The type of soil depends on factors like the parent rock material, climate, relief of the land, and time. Soil has a profile of horizontal layers with different physical and chemical properties. Soil conservation methods aim to prevent problems like erosion, desertification, and contamination through agronomical, biological, and mechanical practices.

1. B Y - A R T I S I N G H
Soil and its types

2. Content
 What is soil?
 Soil formation
 Weathering
 Soil development
 Factors influence soil
formation
 Soil Profile
 Soil composition
 Physical properties of
soil
 Soil texture
 Types of soil and
comparison
 Chemical properties
 Humus
 Soil Water
 Soil Air
 Soil reaction
 Soil Organism
 Problems regarding soil
 Conservation of soil

3. What is soil?
 It is originated from Latin word ‘solum’.
 It is basic natural resources.
 Soil is a mixture of organic matter,
minerals, gases, liquids, and organisms that together
support life.
 The study of soil is called pedology or edaphology.

4. Soil formation

5. Soil formation
It can be divided into two major stages-
1. Weathering
2. Soil development

6. 1. Weathering
This process performed by three methods-
Physical Weathering
Chemical Weathering
Biological Weathering

7. 2. Soil development
 It is also called Pedogenesis or Soil Maturation.
 Organisms such as bacteria, fungi, algae, lichens etc.,
help in this process.
 A mixture of Organic and Inorganic substances is
formed by humus. This is called Soil.

8. Factors
influenced soil
formation
1. 1.Parent rock
2. 2.Climate
3. 3.Relief
4. 4. Time
5. 5. Flora, fauna
and Micro-
organism

9. Soil profile
 A vertical section of soil in which many horizons of soil
are seen is called Soil Profile.
 Horizon-A (Top Soil)
o O1 Horizon
o O2 Horizon
o A1 Horizon
o A2 Horizon
 Horizon-B (Sub-Soil)
 Horizon-C (Parent Rock)
 Horizon-D (Bed Rock)

11. Soil composition

12. Physical properties of soil
1. Soil Colour
It can be different colour in different places but soil colour does
not affect their working system.
2. Porosity
Empty spaces are present among soil particles those have soil
water and soil air.
3. Soil Permeability
The power of soil to allow water to pass through it.

13. 4.Soil texture
Particle size-
Gravel = >5.000mm in diameter.
Fine Gravel = 2.000-5.000mm
Coarse sand = 0.200-2.000mm
Fine sand = 0.020-0.200mm
Silt = 0.002-0.020mm
Clay = <0.002mm

14. Types of soil

16. Chemical properties
 Mineral matter or inorganic matter
o Macronutrients
o Micronutrients
 Organic matter or humus

17. Humus
 It is dark organic matter that forms in
soil when dead plants and animal matter
decays.
Types of Humus-

18. Soil water
It is the most significant factor because the absorption of
minerals and organic matter through roots takes place by
water only.
Soil water balance

19. Types of soil
water-
1.Chemically
combined water
2.Hygroscopic water
3.Capillary water
4.Gravitational water
5.Atmospheric water

20. Soil air
The air present in soil.
Following activities of plant performed by soil air-
 Water absorption
 Growth of roots
 Formation of new root hairs
 Respiration by roots
 Seed germination

21. Soil reaction
 The soil may be neutral, acidic or basic.
 pH of soil varies from 3-9.
 The value of pH the effects the concentration and
availability of other minerals.
 The plant growth is good between 6 to 7.5 pH.

22. Soil organisms
 Soil organisms are commonly
divided into five arbitrary
groups according to size, the
smallest of which are
the protists—including bacteria,
actinomycetes, and algae.

23. Problems of soil
 Soil erosion
 Desertification
 Salinisation and Alkalisation
 Impact of Intensive
Agriculture
 Urbanization and
Contamination

24. Conservation of soil
There are three main methods-
1.Agronomical measures
• Contour farming
• Strip cropping
• Cover cropping
• Crop rotation

25. 2.Biological methods
 Afforestation
 Trenching
 Ley farming
 Silvi-Pastural Practices

26. 3.Mechanical methods
 Bunding
 Terracing
 Gully control
 Ravine reclamation

27. THANK YOU