Ranks Country/Region

Ranks	Country/Region	Irrigated land (km²)
1	China	690,070
2	India	667,000
3	United States	264,000
4	Pakistan	202,000

The earliest known systems of irrigation began in 6000 BC in Egypt and Mesopotamia.

Surface irrigation

Water is distributed over and across land by gravity, no mechanical pump involved.

(It is normally used when conditions are favorable: mild and regular slopes, soil type with medium to low infiltration rate, and a sufficient supply of surface or groundwater. Surface irrigation is widely utilized and therefore a well-known system which can be operated without any high-tech applications)

Localized irrigationgf

Water is distributed under low pressure, through a piped network and applied to each plant.

Localized irrigation is a method of applying water that results in wetting only a small area of the soil surface and sometimes only part of the root zone. Water is applied near the base of the plant so that the application is concentrated in the root zone.

Drip irrigation

A type of localized irrigation in which drops of water are delivered at or near the root of plants. In this type of irrigation, evaporation and runoff are minimized.

Drip irrigation is a type of micro-irrigation system that has the potential to save water and nutrients by allowing water to drip slowly to the roots of plants, either from above the soil surface or buried below the surface. The goal is to place water directly into the root zone and minimize evaporation