Soil Profile Terminology: The Solum
The question asks to identify the upper part of the soil profile showing significant modification due to soil-forming (pedogenic) processes.
Pedogenic Processes Defined
Pedogenic processes refer to the natural processes of soil formation, including weathering, decomposition, eluviation (leaching), illuviation (accumulation), and biologic activity, which transform parent material into distinct soil horizons.
Identifying the Solum
The Solum is the section of the soil profile that includes the horizons most significantly affected by these pedogenic processes. It typically comprises the upper horizons (like A, E, and B) where soil development is evident.
- It represents the true soil, developed from the parent material.
- It shows clear signs of alteration through weathering and biological activity.
Why Other Options Are Incorrect
The other terms refer to different geological or landscape features:
- Catena: A sequence of soils of similar parent material and age but differing in drainage and topographic position, occurring across a landscape.
- Talus: Loose rock debris accumulated at the base of a cliff or steep slope.
- Grus: Residual, weathered rock material, often disintegrated granite, that has not been transported significantly.
Only the Solum accurately describes the altered upper soil profile shaped by pedogenic processes.
Important Questions from Formation Of Soil
- A grassland soil that contains dark and thick mineral surface horizon, abundant humus and basic cations, and remains soft after drying is known as:
- Read the following statements and identify the corresponding soil forming processes
I. It is the process of removal of constituents in suspension or solution by percolating water from upper to lower layers.
II. It is the process of deposition of soil material in the lower layers The production of organic acids accelerates leaching in the soil horizon
Read the following statements about clay particles and choose the CORRECT answer
$\text{I}$ : Clay particles are platy. Therefore water tension acts on their large surface area to cause cohesion.
$\text{II}$ : Clay particles have electrically charged surfaces. Charges on the clay attract opposite charges on other particles, holding them together.From which horizon of the given soil profile is the maximum solute flux released?
