Introduction of Soil. Part-II. Dr. P. C. Patel

Soil is not just dirt; it’s a dynamic, life-sustaining matrix that impacts everything from agriculture to ecosystems. Soil, the biologically active, porous medium that has developed in the uppermost layer of Earth’s crust, plays a crucial role in our planet’s ecosystem.
1. Composition and Importance:
o Minerals: Soil is a complex mixture of minerals, water, air, organic matter, and countless organisms. These components interact dynamically, making soil one of our planet’s most vital natural resources.
A. Organic Matter: It contains the decaying remains of once-living organisms.
B. Support for Plant Life: Soil serves as the “skin of the earth,” capable of supporting plant growth. It acts as a reservoir for water and nutrients, facilitates waste breakdown, and participates in global element cycling .
C. Human Impact: Since the rise of agriculture and forestry, practical awareness of soils and their management has become essential. Quantitative science has opened opportunities for improved soil practices .
2. Soil Profile and Horizons:
A. Soil Profile: Imagine slicing through the ground vertically. The resulting cross-section is the soil profile. It consists of distinct layers called horizons.
B. Horizons: Soil has O Horizon, A Horizon, B Horizon, C Horizon and R Horizon (Bedrock)
3. Soil Erosion and Pollution:
A. Erosion: Soil erosion, caused by factors like water, wind, and human activity, threatens soil health.
B. Pollution: Contaminants from chemicals, heavy metals, and improper waste disposal can degrade soil quality .