Final answer:
Four irrigation methods are Flood, Drip, Center pivot, and Subsurface irrigation. Strategies to reduce water waste include improved irrigation scheduling, rainwater harvesting, mulching, and using drought-resistant crops. These methods are applicable in both more- and less-developed countries.
Step-by-step explanation:
Describing four irrigation methods, we have: Flood irrigation which involves flooding an entire field with water, allowing it to soak in evenly; Drip irrigation, which delivers water directly to the base of each plant through a network of tubes and emitters, greatly reducing water waste; Center pivot irrigation, where equipment rotates around a pivot, irrigating a circular area with sprinklers; and Subsurface irrigation, where water is supplied below the surface of the soil directly to the root zone.
To reduce water waste in irrigation, some strategies that can be employed in both more- and less-developed countries include: improved irrigation scheduling to deliver water only when crops need it; rainwater harvesting to store rain that can be used during drier periods; mulching to maintain soil moisture; and the use of drought-resistant crops that require less water.
In more developed regions like Israel and California, the use of advanced techniques such as fertigation and materials that reduce transpiration helps conserve water. In less developed regions, focusing on improving water quality and accessibility may take precedence, though efficient irrigation methods still play a significant role in reducing water usage.