Correct Option: A. Mapping land boundaries Detailed Explanation: Farm surveying is a critical practice in agriculture that involves measuring and mapping land to understand its dimensions, boundaries, and topography. The primary purpose of farm surveying is to map land boundaries accurately. This is essential for several reasons:

1. Legal Clarity: Knowing the exact boundaries of a farm helps in establishing legal ownership and preventing disputes with neighboring landowners. Clear boundaries ensure that farmers know where their land ends and where someone else's begins, which is crucial for maintaining good relationships and avoiding legal issues.
2. Land Use Planning: Accurate mapping allows farmers to plan their land use effectively. By understanding the layout of their property, farmers can make informed decisions about where to plant crops, build structures, or allocate resources. This planning is vital for maximizing productivity and ensuring sustainable land management.
3. Resource Management: Farm surveying helps in identifying the best areas for different agricultural practices. For instance, certain parts of a farm may be more suitable for specific crops based on their location, soil type, and drainage. By mapping these features, farmers can optimize their operations.
4. Infrastructure Development: When planning for infrastructure such as irrigation systems, roads, or storage facilities, having a detailed map of the land is essential. Surveying provides the necessary data to design these systems effectively, ensuring they are placed in the most advantageous locations.
5. Environmental Considerations: Understanding the topography and boundaries of a farm can also help in assessing environmental impacts. For example, knowing where water flows can inform decisions about erosion control and conservation practices.

Why Other Options Are Weaker:

• B. Determining soil fertility: While soil fertility is crucial for agricultural productivity, it is not the primary focus of farm surveying. Soil fertility assessments typically involve soil testing and analysis rather than surveying techniques. Surveying may provide some context for soil types across a farm, but it does not directly measure fertility.
• C. Assessing crop yield: Crop yield assessment is a separate process that involves evaluating the amount of produce harvested from a given area. This is typically done after crops have been planted and harvested, using methods such as sampling and weighing. Surveying does not directly assess yield; it may help in planning for yield assessments but is not its primary purpose.
• D. Identifying pest infestations: Identifying pest infestations is a critical aspect of crop management but is not related to the surveying of land. Pest identification usually involves visual inspections, traps, and monitoring techniques rather than surveying methods. While surveying can help in understanding the layout of fields where pests may be present, it does not directly identify infestations.

Summary:

• The primary purpose of farm surveying is to accurately map land boundaries.
• Accurate boundary mapping is essential for legal clarity, land use planning, resource management, infrastructure development, and environmental considerations.
• Other options like determining soil fertility, assessing crop yield, and identifying pest infestations are important but not the main focus of farm surveying.