Select the incorrect statement.

Options

A. NPK fertilisers are insoluble in water and rich in nitrogen, phosphorus and potassium salts.
B. Compost is made by burying all available organic materials in a pit and is rich in organic nutrients.
C. Pongal and Bihu are celebrated at the time of harvesting of crops.
D. Granaries are large buildings where grains are stored inside gunny bags.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Statements:**
- We need to evaluate four statements related to crop production and management to identify which one is incorrect.

2. **Evaluating the First Statement:**
- The first statement claims that "NPK fertilizers are insoluble in water and rich in nitrogen, phosphorus, and potassium salts."
- **Analysis:** NPK fertilizers are indeed rich in nitrogen, phosphorus, and potassium, but they are soluble in water. This solubility is essential for plants to absorb these nutrients. Therefore, this statement is incorrect.

3. **Evaluating the Second Statement:**
- The second statement says, "Compost is made by buying all available organic material in a pit and is rich in organic nutrients."
- **Analysis:** Compost is made from organic waste materials like vegetable peels and tea leaves, which are placed in a pit to decompose. This process enriches the soil with organic nutrients. Thus, this statement is correct.

4. **Evaluating the Third Statement:**
- The third statement mentions, "Pongal and Bihu are celebrated at times of harvesting of crops."
- **Analysis:** Pongal is celebrated in Tamil Nadu, and Bihu is celebrated in Assam, both during the harvest season. This statement is also correct.

5. **Evaluating the Fourth Statement:**
- The fourth statement states, "Granules are large buildings where grains are stored inside guinea bags."
- **Analysis:** Granaries are indeed large structures designed for storing grains, ensuring protection from moisture and pests. This statement is accurate as well.

6. **Conclusion:**
- After evaluating all four statements, the first statement about NPK fertilizers being insoluble in water is the only incorrect statement.

**Final Answer:**
The incorrect statement is: "NPK fertilizers are insoluble in water and rich in nitrogen, phosphorus, and potassium salts."

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