Question

The process of cycling of nutrients from soil to the plant and back to the soil is called ________.

• A. Nutrient pumping
• B. Nutrient absorption
• C. Mineralization
• D. Nutrient cycling

Hint:

Deep-rooted trees in agroforestry systems are highly valued because they help close the nutrient loop, making nutrient cycling more efficient and reducing the need for chemical fertilizers.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
This question focuses on biogeochemical pathways and the movement of essential chemical elements through different components of an ecosystem.

Step 2: Detailed Explanation:
Let us examine the environmental terms listed:
1. Nutrient absorption:
This is the physiological process where plant roots take up dissolved inorganic nutrients from the soil solution.
It represents only the upward movement of nutrients.
2. Nutrient pumping:
This is a specific agroforestry term.
It describes how deep-rooted trees absorb nutrients from deep soil layers and bring them to the surface, making them available to shallow-rooted crops via leaf litter.
3. Mineralization:
This is the biological process where decomposers convert organic nutrients bound in dead organic matter back into inorganic, plant-available forms.
4. Nutrient cycling:
This is the complete, circular ecological pathway.
It includes:
- Plant absorption of nutrients from the soil.
- Incorporation of those nutrients into plant tissues.
- Return of organic matter to the soil via leaf litterfall, root turnover, and plant decay.
- Decomposition and mineralization processes that restore the nutrients to the soil.

Step 3: Final Answer:
The complete cycle of nutrients between the soil and plants is called Nutrient cycling.
Thus, Option (D) is correct.