Question

The soil with more than 20 Kg/ ha Phosphorus are rated as

• A. Low in P
• B. Medium in P
• C. High in P
• D. Very low in P

Hint:

Standard soil fertility ratings for available Phosphorus (P):
- Low: \(< 10 \text{ kg/ha}\)
- Medium: \(10 - 20 \text{ kg/ha}\)
- High: \(> 20 \text{ kg/ha}\)
Knowing these standard values helps you solve soil test interpretation questions quickly.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Soil testing is essential for evaluating soil fertility and determining fertilizer recommendations for crops.
The available phosphorus content in soil is commonly extracted using Olsen's method (for neutral to alkaline soils) or Bray's method (for acidic soils) and is classified into fertility ratings: Low, Medium, or High.

Step 2: Detailed Explanation:
In India, the standard fertility rating limits for available phosphorus (\(P\)) in soil, expressed in kilograms per hectare (kg/ha), are categorized as follows:
Low available Phosphorus: Less than \(10 \text{ kg P/ha}\).
Medium available Phosphorus: Between \(10\) and \(20 \text{ kg P/ha}\) (some systems use \(10\) to \(25 \text{ kg P/ha}\)).
High available Phosphorus: More than \(20 \text{ kg P/ha}\) (or more than \(25 \text{ kg P/ha}\)).
Let us analyze the options:
- Option (A) Low in P: Corresponds to soils containing less than \(10 \text{ kg P/ha}\).
- Option (B) Medium in P: Corresponds to soils containing \(10\) to \(20 \text{ kg P/ha}\).
- Option (C) High in P: Corresponds to soils containing more than \(20 \text{ kg P/ha}\).
- Option (D) Very low in P: Typically defined as less than \(5 \text{ kg P/ha}\).
Therefore, a soil with more than \(20 \text{ kg/ha}\) of available phosphorus is rated as High in P.

Step 3: Final Answer:
The correct option is (C).