The development of drip irrigation, the use of driplines underground in the plant root zone offers substantial advantages for permanent crops such as sugarcane, plantation crops, tree crops and certain types of landscaping. To be successful it requires special driplines and system installation and system maintenance and management. PIAL provides products, system design, supply & installation and maintenance & agronomic support for successful SDI installations.
Advantages of SDI
How SDI is Different from Surface Drip
The enemy of controlling water movement in soil is gravity which will always pull water downwards and eventually away from the root zone. The other force is capillary which moves water in all directions but which weakens when soil becomes saturated that is when all pore spaces are full of water. At that point, gravity takes over and moves water downwards. Applying water at the surface means that gravity has to be used to move water into the root zone and some oil will be saturated and deprived of oxygen which is not an ideal state. If water is applied right in the root zone, as in SDI, capillary action can be used to move water throughout the root zone. Irrigation can be stopped before the soil is saturated. Thus SDI works best with frequent but relatively small quantities of water. However, this also requires an accurate delivery system with correct emitter spacing for plant and soil types and each emitter delivering the same amount of water.
Water distribution 10 hours after 1 hour of watering:
System Design, Installation and Maintenance
Design of the SDI system will be provided by PIAL after a site inventory and survey which takes into account topography, soil type and strata, water source, quality and quantity, power availability, crop pattern, crop variety, climate, etc. Special to SDI are correct filter selection, air release/vacuum valve placement, dripline drain manifolds and chemical injection facility.
Driplines for some crops – certainly sugarcane, can be mechanically installed using a machine mounted on a tractor.
Maintenance involves regular filter cleaning or backflushing, acid and other chemical injection, regular field inspection and action in case of rodent or insect infestation. Root intrusion has to be controlled by product features and injection of a herbicide.