A soil is said to be fertile when

Options

A. It is rich in organic matter
B. It has capacity to hold water
C. It has a capacity to hold nutrients
D. It holds water `&` all essential nutrienets in a definite proportion.

Answer

### Step-by-Step Solution:

1. **Definition of Fertile Soil**: A soil is considered fertile when it supports healthy plant growth. This means it must provide essential nutrients and have good physical properties.

2. **Rich in Organic Matter**: Fertile soil is rich in organic matter, which improves soil structure, enhances nutrient availability, and increases water retention.

3. **Water Retention Capacity**: Fertile soil has the ability to hold water effectively. This is crucial for plant survival as water is necessary for various physiological processes.

4. **Nutrient Availability**: Fertile soil contains a balanced proportion of essential nutrients required for plant growth. Key nutrients include nitrogen (N), phosphorus (P), and potassium (K), which are vital for plant health.

5. **Presence of Micronutrients**: In addition to macronutrients, fertile soil should also contain adequate amounts of micronutrients such as boron, chloride, copper, cobalt, iron, manganese, magnesium, molybdenum, sulfur, and zinc. These minerals play important roles in various plant functions.

6. **Good Soil Structure**: Fertile soil has a good structure that allows for proper drainage and aeration. This promotes root growth and overall plant health.

7. **Microorganism Diversity**: Fertile soil contains a variety of microorganisms that contribute to nutrient cycling and organic matter decomposition, further supporting plant growth.

8. **Top Soil Presence**: Fertile soil typically has a significant amount of topsoil, which is the uppermost layer of soil rich in organic matter and nutrients.

9. **Conclusion**: Therefore, a soil is said to be fertile when it holds water and all essential nutrients in a definite proportion.