Soil conservation is the practice of protecting and preserving the soil from degradation, erosion, and other forms of damage. It involves adopting various methods and techniques to prevent soil erosion, improve soil fertility, and maintain its overall health. A synonym for soil conservation is "protection."

Explanation:
b) Protection

Soil conservation aims to protect the soil from erosion, degradation, and depletion, ensuring its long-term productivity and sustainability. Here's a detailed explanation of why "protection" is the correct synonym for soil conservation:

1. Soil conservation prevents erosion: Erosion is the process of soil particles being carried away by wind or water. By implementing soil conservation practices, such as contour plowing, terracing, and mulching, the soil is protected from erosion caused by rainfall, wind, or human activities.

2. Soil conservation improves soil fertility: One of the primary goals of soil conservation is to maintain and enhance soil fertility. This involves adding organic matter, such as compost or manure, to the soil to improve its nutrient content. By protecting the soil from erosion and nutrient loss, soil conservation practices contribute to the overall protection and enhancement of soil fertility.

3. Soil conservation protects against degradation: Soil degradation refers to the decline in soil quality and productivity, often caused by factors like deforestation, overgrazing, and improper land use. By implementing soil conservation techniques, such as crop rotation, agroforestry, and cover cropping, the soil is protected against degradation, preserving its structure, texture, and nutrient content.

4. Soil conservation maintains soil health: Soil health is essential for the growth of plants and the overall sustainability of ecosystems. Soil conservation practices help maintain soil health by minimizing compaction, improving water infiltration, promoting beneficial soil organisms, and reducing the use of harmful chemicals. By protecting the soil from degradation, erosion, and other forms of damage, soil conservation contributes to the long-term health and productivity of the soil.

In conclusion, "protection" is an appropriate synonym for soil conservation as it encompasses the various practices and techniques aimed at safeguarding the soil from erosion, degradation, and nutrient depletion.