Soil Science short note
Fundamentals of Soil Science
- Fundamental of Lithosphere
- Father of Soil Science – Dokucheav
- Father of Indian Soil Science – John Walter Leather
- O horizon: Mostly made up of organic materials.
- Humus: Divided into fulvic and humic acids.
- Soil formation is a process known as pedogenesis.
- Essential for cation exchange capacity (CEC) are clay minerals.
- E horizon: Mineral leaching is at its highest point.
- The three main macronutrients are potassium, phosphorus, and nitrogen.
Properties of Soil
- The pH scale quantifies the acidity and alkalinity of soil.
- The ratio of clay, silt, and sand in the soil.
- Clay soil has the highest capacity to store water.
- Amendment: Improving the soil’s structure by adding organic materials.
- Carbon to nitrogen ratio in soil (C:N ratio).
Munsell Colour System
A technique for accurately detecting and expressing colours. In 20th century, Albert H. Munsell created it. Many domains, such as soil research, art, design, and industry, frequently utilize this technique. Where precise color specification is essential.
Important Elements:
Hue: Any of the primary colour families. It including blue, purple, green, yellow, and red. The Munsell system uses letters to represent hues that are arranged in a circle:
- Red (R), Yellow (Y), Green (G), Blue (B), and Purple (P) are the five primary hues.
- YR (yellow-red), GY (green-yellow), BG (blue-green), PB (purple-blue), and RP (red-purple). These are the five intermediate hues.
- Each hue has more subdivisions. which combine to produce a more complex color scheme.
Value: A color’s luminance or darkness. 0 representing black and 10 representing. 0 at the bottom and 10 at the top. An axis of neutral grey is represented by this vertical scale.
Chroma: A color’s saturation or intensity, determined by measuring it radially from the neutral grey axis. Colours with a low chroma are muted or dreary, and colours with a high chroma are bright or pure. The length of chroma scales varies with hue and value.
Colour Notation:
The Munsell colour system identifies each colour with a notation that consists of all three elements in the following order:
Hue Value/Chroma (5YR 5/6, for example)
A sample of soil bearing the marking 5YR 5/6 indicates:
Colour: Red-yellow (5YR)
Value: 5 (lightness of medium)
Chroma: 6 (intensity moderate)
Problems & Procedures with Soil
- Leaching of basic cations is the main cause of soil acidity.
- Factors influencing soil formation: geography, parent material, and climate (NOT human involvement).
- Granular soil structure is the ideal type.
- Soil colloids are essential for aeration, nutrient retention, and water infiltration.
- Excessive irrigation is the cause of salt in soil.
- B horizon: Also known as “subsoil.”
- Erosion is the process by which wind or water carry away soil particles.
Chemistry & Organic Matter
- Fulvic acid: Metal ion chelation capability.
- Porosity is the measure of soil’s pore space with respect to its volume.
Further Reading: Click here
