What main component does the center pivot irrigation system utilize for water delivery?

The center pivot irrigation system is primarily designed around a wheeled system that rotates around a central point. This unique setup allows for an efficient and effective method of distributing water over agricultural fields. The central pivot is anchored at a specific point and utilizes long segments of pipe that support sprinkler heads, which then deliver water in a circular pattern as the system rotates.

This design allows for a uniform distribution of water, ensuring that crops receive adequate moisture while minimizing waste. The wheels permit the structure to move seamlessly across the field, adapting to various soil structures and plant layouts. The rotating mechanism is pivotal in maintaining efficiency as it requires less labor and can cover large areas with minimal energy input.

In contrast, the other options do not accurately describe the center pivot system. Straight pipes would not provide the flexibility and coverage needed for large fields. Underground reservoirs might serve as water sources but do not play a role in the irrigation method itself. Gravity-fed channels typically rely on slope for water movement and are less suited for the design and operational flexibility that center pivot systems offer.