Question

Which one of the following minerals is the source of P in soils?

• A. Apatite
• B. Calcite
• C. Gypsum
• D. Magnetite

Hint:

Apatite is the primary mineral source of phosphorus ($P$); Feldspar and Mica are primary sources of potassium ($K$).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Soil primary and secondary minerals serve as geological parent sources of essential macro- and micronutrients.

Step 2: Detailed Explanation:
Apatite ($[\text{Ca}_5(\text{PO}_4)_3(\text{F},\text{Cl},\text{OH})]$) is the primary phosphate-bearing mineral found in igneous and sedimentary rocks, serving as the ultimate geological source of phosphorus in soils.
Calcite ($\text{CaCO}_3$) supplies calcium, gypsum ($\text{CaSO}_4\cdot 2\text{H}_2\text{O}$) supplies calcium and sulfur, and magnetite ($\text{Fe}_3\text{O}_4$) is an iron oxide mineral.

Step 3: Final Answer:
Therefore, apatite is the mineral source of phosphorus in soils.