AP Environmental Science

Answer: B - Flood irrigation is a technique that utilizes water that is pumped into trenches that are dug into the fields.

Key Takeaway: Generally, there are three main irrigation techniques used in modern agriculture: spray irrigation, drip irrigation, and flood irrigation.

In spray irrigation, hoses with spray attachments are planted in fields, similar to watering your lawn at home. This requires equipment that can pump and spray the water. Drip irrigation uses pipes with holes in them to route the water. These pipes are laid alongside the crops. This is generally the method that uses the least amount of water. Last is flood irrigation, in which water gets pumped into trenches dug into the fields, allowing the water to flow along the ground to the crops. Although this method is extremely cheap and does not require special equipment, much of the water is wasted, as over half never reaches the crops.