Subsurface Drip Irrigation- Types, Advantages & Installation

Sub-Surface Drip Irrigation (SDI)

Date: 03-9-2021

What is SDI (Sub-Surface Drip Irrigation)?

The application of water through a Drip Irrigation System by placing the Inline below the soil surface is called a ‘Sub- Surface Drip irrigation System’. Here, the inline is installed around 4” to 12” below the soil surface with the help of an agricultural implement.

Usually, it is the tendency of water to travel 2/3 below soil surface by infiltration and 1/3 above the soil surface by capillary movement. Also, depending on the soil type the water movement can be vertical as well as horizontal. This concept has played a vital role in designing the Sub-Surface Irrigation Systems built by Kothari Group Drip Irrigation Manufacturers and Suppliers in India.

The major factor contributing to the water requirement of plants is Evapo-transpiration. Transpiration through plant leaves is a non-controllable factor. Hence, Evaporation has a major impact on the water requirement of the plant; to avoid this water loss Sub-Surface Drip Irrigation Systems are the best solution.

Types of SDI

Shallow Burial SDI:
  • Shallow Burial SDI is installation of SDI less than 4”, below the soil surface. This type of Shallow Burial System is used for low wall thickness inline. The thin wall inline is usually blown by wind and a high depth burial cannot sustain the soil pressure. Hence, the option of Shallow Burial SDI solves both the problems.
  • Also, the Inline can be easily removed and disposed after the season. This type of SDI is used only for single season crop like vegetables, watermelon etc.
Deep Burial SDI:
  • Deep Burial SDI refers to the installation of SDI that is from 4” to 12”, below the soil surface. This type of Burial System is used for high wall thickness inline. The thick wall Inline is used for burial of high depth as it can sustain the soil pressure.
  • This type of SDI is used for all types of crops like tomato, sugarcane, cotton etc. This system facilitates the Drip Irrigation Systems to be used for as many as 10 years. It has more life compared to the Drip Irrigation Systems on ground.

System and Installations

  • With a proper plot survey, the design of the SDI system can be made considering all the field parameters like water and power availability.
  • A SDI system includes all the components that are needed for a regular Drip Irrigation System. Here, the header unit must include a sand filter, a secondary filtration (Screen or Disc Filter), fertigation systems along with all safety valves like NRV, Air Valve, Pressure gauges, PRV etc.
  • In the Field unit along with main, sub-main, Inline, Control Valve, Air valve, Inline end caps are used instead of individual inline and flushing manifold is installed with a single valve to facilitate immediate inline flushing. The main, sub-main & flushing manifolds are buried at desired depths.
  • For the Drip Irrigation Systems and Equipments to work properly it is important to use good quality trustable materials from Kothari Group Drip irrigation Systems Manufacturers and Suppliers in India.
  • The Inline used is usually the PCND (Pressure Compensating No Drain) or PCAS (Pressure Compensating Anti Siphon) that ensures that the systems do not choke and are long lived.
  • The installation requires specially designed tractors, operated implement to bury inline in the desired depth below the soil surface. Even the dripper discharge is less compared to the on ground regular Drip Irrigation Systems. This system is usually installed before the actual plantation.
  • The system is flushed properly before its operation.


  • The SDI system has the highest water use efficiency, which goes up to 95%
  • The water loss is reduced by 20% -25% compared to the regular Drip Irrigation Systems as water loss due to evaporation is avoided.
  • The soil health and due to which the crop health as reducing the wet-zone/humidity above the soil surface in crop canopy area is maintained.
  • The formation of weed is also reduced that tremendously decreases the cost of inter-cultivation.
  • Since, the Plant roots are chasing the water; a very healthy root structure has been developed leading to growth in the yield.
  • The quantity of pesticides, fertilizers that needed to be applied reduces by SDI which decreases the costing involved.
  • The damage of inline due to movement of human & animals has been reduced in SDI compared with surface drip system.


  • Operating the system on a regular basis is necessary to avoid choking of the system.
  • Key maintenance includes flushing of the Inline with the help of flushing manifold on a daily basis.
  • The chemical flushing of the system on periodic basis depends upon the water quality, which is important for extending the life of the system.

- Sandeep Deshpande
AGM- Sales & Marketing