Soil Science Concepts and Techniques
6) Eluviation/Illuviation Process
Luvisols vs. Podzols
Eluviation is the leaching or removal/transport of suspended or dissolved soil components to underlying horizons. This includes:
- Degradation (removal of soluble salts)
- Illimerization (removal of clay)
- Podzolization (removal of Fe and Al oxides and organic substances, leading to E horizon formation)
Illuviation is the accumulation of substances removed from the overlaying horizon (eluviation), leading to the formation of argic/spodic/natric horizons.
Plate Tectonics, Solar System Origin, and Life’s Genesis
Plate Tectonics
Continental drift and seafloor spreading unite in a more complete theory known as plate tectonics. Under this theory, the rigid outer layer of the Earth is over a weaker region called the asthenosphere. The lithosphere is divided into several pieces called plates that are moving and continually changing in shape and size. The plates move and deform along their edges.
When the plates separate, mantle material rises, creating new ocean floor. When the plates collide, mountain ranges
Read MoreEfficient Irrigation Methods and Fertilizer Use for Crop Production
Irrigation Systems for Optimal Crop Growth
The sprinkler system artificially incorporates water into the soil to meet plant needs, unlike natural rainwater, where incorporation is often less efficient.
Objective of Irrigation
The primary objective of irrigation is to maintain optimal groundwater levels and soil moisture. This is crucial for economic crop production, especially when considering the resources invested. When crops show signs of water stress, artificial irrigation becomes necessary.
Irrigation
Read MoreUnderstanding Wood: Properties, Protection, and Uses
Wood: An Overview of Properties and Uses
Wood’s strength and flexibility depend on the direction of its fibers. As an organic material, its lifespan is shorter compared to other materials.
- Advantages: Easy to use, suitable for temporary structures, easy to transport, low density, easy to work with, lightens structures, provides thermal and acoustic insulation.
Disadvantages: Susceptible to fungi and insects, not an inert material, swells with water, prone to premature aging, can rot and is vulnerable
Read MoreUnderstanding Plate Tectonics: Pangea, Continental Drift, and Plate Boundaries
Understanding Plate Tectonics
The global theory of plate tectonics explains the cause of phenomena occurring in the geosphere, including mountain formation, volcanoes, and earthquakes.
Pangea and Panthalassa
Pangea was a supercontinent where all continents were united. The unique ocean surrounding it was called Panthalassa.
Theory of Continental Drift
Alfred Wegener developed the theory of continental drift based on cartographic, geographical, and paleontological data. This theory posits that continents
Read MoreAtmosphere: Composition, Structure, and Climate Dynamics
Atmospheric Composition
The atmosphere consists of major and minor constituents, including reagents and non-variable elements.
Structure and Function of the Atmosphere
The sun emits ultraviolet, visible, and infrared electromagnetic radiation (shortwave, visible, and longwave). Radiation from the center of the spectrum penetrates atmospheric layers most easily, primarily as visible light. Short wavelengths have high energy and penetrating power. Longer wavelengths are emitted by the Earth and used
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