In the "Irrigation and Drainage" chapter of the handbook, different methods of watering crops are discussed. Farmers have used gravity to water fields for a long time, but now they can also use engines and sprinklers to mimic rainfall. Microirrigation is becoming more popular in areas with little water, high crop values, and practical technology. Despite this, surface irrigation is still the most common way to water crops worldwide. In some regions, sprinkler irrigation is being used more and more. Tables provide estimates of the total land area irrigated and the percentage of different irrigation methods used in different areas. Asia has the most land irrigated, mostly using surface irrigation.