Which of the following is NOT a type of microirrigation system?

The classification of irrigation systems is crucial for understanding their efficiency and application in various agricultural contexts. Microirrigation systems are designed to deliver water directly to the root zone of plants, minimizing water loss and maximizing effectiveness. The systems listed as drip, subsurface, and bubbler are all types of microirrigation systems.

Drip irrigation involves delivering water through a network of tubing and emitters, allowing for precise and efficient watering of plants. Subsurface irrigation is similar, but it involves burying the system underground, which can further reduce evaporation and surface runoff. Bubblers work by providing a larger volume of water to a limited area, typically suitable for trees and shrubs.

In contrast, flood irrigation is a conventional method that involves inundating an entire field with water. This method does not effectively concentrate water at the root zone and often leads to substantial water wastage through evaporation and runoff. Therefore, flood irrigation does not fit the definition of a microirrigation system, making it the correct answer for this question.

Understanding these distinctions is essential for selecting the right irrigation method to ensure efficient water use and crop health.