Final answer:
The subject of this question is Agriculture. The system described involves delivering water at low pressure through buried mains and sub mains, and distributing it to the soil through a network of perforated tubes or emitters.
Step-by-step explanation:
The subject of this question is Agriculture. The described system involves delivering water at low pressure through buried mains and sub mains. It also mentions the distribution of water to the soil through a network of perforated tubes or emitters. This method is much more efficient than traditional sprinkler systems for agricultural irrigation.