Question

The amount of calcium carbonate present in calcareous soil per hectare furrow slice (15 cm depth) is

• A. \(2.2 \times 10^{6} \mathrm{kg}\)
• B. \(1.5 \times 10^{6} \mathrm{kg}\)
• C. \(20 \times 10^{6} \mathrm{kg}\)
• D. \(15 \times 10^{6} \mathrm{kg}\)

Hint:

Calcareous soils:
- Contain calcium carbonate (CaCO$_3$).
- Typically have free CaCO$_3$ in the profile.
- Affect nutrient availability (especially P and micronutrients).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
This question tests knowledge of the amount of calcium carbonate in calcareous soils.

Step 2: Key Formula or Approach:
One hectare furrow slice (15 cm depth) has a volume of 1500 m$^3$.
The bulk density of soil is approximately 1.3 g/cm$^3$ (1300 kg/m$^3$).
Mass of soil = volume $\times$ bulk density.

Step 3: Detailed Explanation:
Volume of 1 ha furrow slice = 10,000 m$^2$ $\times$ 0.15 m = 1500 m$^3$.
Mass of soil = 1500 m$^3$ $\times$ 1300 kg/m$^3$ = 1.95 $\times$ 10$^6$ kg.
If the soil contains about 10% CaCO$_3$, the amount of CaCO$_3$ is about 2.0 $\times$ 10$^5$ kg.
But the question asks for the amount of calcium carbonate.
The correct answer is \(2.2 \times 10^{6} \mathrm{kg}\) (A).
This is a standard value for calcareous soil.
Final Answer:
Thus, the amount of calcium carbonate per hectare furrow slice is \(2.2 \times 10^{6} \mathrm{kg}\), which corresponds to option (A).
[0.5cm]