The "Irrigation, drainage, and salinity" international source book discusses how to manage water in agriculture. It talks about techniques to help plants grow by providing the right amount of water and removing excess through drainage. The book also looks at dealing with salt in the soil, which can harm crops. The researchers share ideas from all over the world to see what works best. They compiled this information into a helpful guide for farmers and land managers. Overall, the book aims to help people understand how to water their crops effectively, maintain good soil conditions, and improve their harvests.