3.3. Sub-surface Irrigation

▪ It is also called sub irrigation method or underground irrigation.
▪ It is the practice of applying water to soils directly under the surface of soil.
▪ Moisture reaches the plant root through capillary action of water.
▪ Either trenches are constructed or underground porous pipelines are installed for sub-surface irrigation.
▪ Water is discharged into trenches or porous pipes.
▪ Water moves laterally and upward to moisten the root zones.

Advantages of sub-surface irrigation:

▪ Soil can be maintained at suitable moisture condition.
▪ Evaporation loss from soil surface is minimized.
▪ Can be used for soil with low water holding capacity.

Disadvantages of sub-surface irrigation:

▪ High risk of clogging.
▪ Salt may accumulate especially if saline water is used.
▪ Emitters can be damaged or blocked by root hairs.
▪ Growth of algae may occur.
▪ Suspended organic matter and clay may damage the system.
▪ Rodents and mice may chew the pipes which results in lot of repair work.
▪ Heavy materials and equipments may damage the pipeline.