Bone is used as a fertilizer because it contains the following plant nutrient :

Question

Accepted Answer

Bone is used as a fertilizer primarily because it contains phosphorus, which is a vital nutrient for plant growth. Phosphorus plays a crucial role in various plant processes, including energy transfer, photosynthesis, and nutrient movement within the plant. It is a component of ATP (adenosine triphosphate), which is essential for energy transfer in cells, and is also a part of DNA and RNA, which are necessary for genetic information and protein synthesis. Phosphorus helps in root development, flower and fruit production, and overall plant vigor, making it an indispensable nutrient in agriculture and gardening.

Now, let's examine why the other options are incorrect:

1. **Oxygen**: While oxygen is essential for plant respiration and photosynthesis, it is not a nutrient that is supplied through fertilizers. Plants obtain oxygen from the air and water, not from soil amendments like bone meal.

2. **Sodium**: Sodium is not considered a primary plant nutrient. In fact, high levels of sodium can be detrimental to plant growth, leading to soil salinity issues. Therefore, sodium is not a reason for using bone as a fertilizer.

3. **Carbon**: Carbon is a fundamental element for all life forms and is a major component of organic compounds. However, plants primarily obtain carbon from carbon dioxide in the atmosphere through the process of photosynthesis, not from fertilizers. Thus, carbon is not the nutrient provided by bone meal.

In conclusion, phosphorus is the key nutrient found in bone that makes it valuable as a fertilizer, supporting Option 4 as the correct answer.