irrigate

Irrigate is the act of supplying water to land or crops to promote growth, yield, or the restoration of moisture in the soil. The practice encompasses the deliberate and controlled application of water to soil, usually through engineered systems rather than relying on natural rainfall. Irrigation is a key component of agriculture in arid and semi-arid regions and can also support landscapes and soil rehabilitation.

There are several irrigation methods. Surface irrigation distributes water over the land by gravity, including flood, furrow, and border strip techniques. Sprinkler irrigation uses pressurized water delivered through pipes and distributed by sprinklers, which can cover large areas with adjustable patterns. Drip or micro-irrigation applies water directly to the plant root zone through emitters, minimizing evaporation and runoff. Subsurface or subirrigation delivers water below the soil surface. Irrigation can use fresh water or treated wastewater, depending on water quality requirements and environmental considerations.

Effective irrigation relies on planning, measurement, and timing. Scheduling often depends on crop water requirements, soil moisture, and weather data, with technologies such as soil moisture sensors, evapotranspiration estimates, and computerized controllers. Efficiency is affected by losses to evaporation, deep percolation, runoff, and wind drift; hence the choice of method, emitter spacing, and management practices is important. Environmental concerns include water scarcity, salinization, drainage issues, and impacts on groundwater. Water rights and governance shape irrigation programs in many regions.