To irrigate means to bring water to crops or land through artificial systems like pipes, canals, or sprinklers. Instead of depending entirely on rain, farmers can irrigate their fields to make sure plants get the water they need to grow.

Irrigation transformed human civilization. Ancient farmers discovered they could dig channels to carry river water to their fields, allowing them to grow food even during dry seasons. The ancient Egyptians irrigated crops using water from the Nile River. The ancient Mesopotamians built complex canal systems thousands of years ago. These irrigation systems let people settle in one place, grow surplus food, and build cities.

Today, farmers irrigate using various methods: some flood entire fields, others use rotating sprinklers, and some use drip systems that deliver water directly to each plant's roots. In dry regions like California or Arizona, irrigation makes farming possible where crops couldn't otherwise survive.

A doctor might also irrigate a wound, meaning to flush it with water or a medical solution to clean it. But most commonly, irrigation refers to watering farmland to help feed the world's population.