What advantage does sub-surface irrigation provide over surface irrigation?

Sub-surface irrigation offers distinct advantages, particularly in reducing both evaporation and weed growth. This irrigation method delivers water directly to the root zone of plants through buried pipes or tubes, significantly minimizing water loss due to evaporation that is common with surface irrigation. By keeping water below the surface, the moisture directly benefits the plants and is less susceptible to being lost to the atmosphere.

Additionally, because the watering occurs below the surface, it creates less favorable conditions for weeds, which generally thrive when water is available on the surface. Consequently, this not only conserves water but also reduces the need for herbicides and other weed management practices, leading to a more efficient and environmentally friendly irrigation solution.

This effectiveness in managing water usage and plant health contrasts with the other choices, which may not fully capture the advantages of sub-surface irrigation. For example, while it might have different costs associated with maintenance or usage of water, the primary benefit of reduced evaporation and weed growth stands out as a critical advantage in effective irrigation practices.