Published in the Journal: October 2019
Drip irrigation delivers water directly to the root zone, allowing for precise application of water and fertilizers. However, effective drip irrigation requires careful maintenance of its main components, including main pipes, filters, venturi systems, and lateral pipes with emitters. If any of these parts malfunction, the system’s efficiency declines.
Cleaning the System
To clean drip irrigation systems, hydrochloric acid (32% concentration), sulfuric acid (93% concentration), or phosphoric acid (85% concentration) can be used. Since sulfuric acid is highly toxic, it is rarely used. Phosphoric acid should be avoided if water has high calcium content, as it may form calcium phosphate deposits.
Preventing Carbonate Deposits
To prevent carbonate build-up, acids should be regularly introduced into the water during irrigation, especially if carbonate levels are high. Deposits are difficult to remove once they harden, as they clog emitters. Acid should be added to maintain water at a pH of 7. To determine the required amount, use pH strips to measure water quality regularly, as it can vary.
Removing Blockages
Hydrochloric acid is commonly used to dissolve blockages. The system should operate at a pH of 4 for the acid to be effective. To start, run the system before adding the acid to prevent it from sitting idle in small pipes or fittings. Acid-treated water should flow continuously for 30-40 minutes, after which the system should be flushed with clean water.
PVC and Lateral Pipe Maintenance
Tiny sand particles may pass through filters and reach PVC pipes and emitters. To remove this, end caps on lateral pipes should be opened every 8-15 days to release debris.
Cleaning the Sand Filter
Sand filters trap dust and particles, preventing them from entering the irrigation lines. Clean the sand filter weekly using one of these methods:
- Backwash Method: By reversing the water flow, debris rises to the top, clearing the sand filter.
- Chemical Method: Chlorine or hydrochloric acid can be used to dissolve carbonates and iron deposits. The amount of chemicals depends on water quality.
Disk Filter Maintenance
Like screen filters, disk filters should be cleaned daily. If the disk wears out, replace it to maintain filtration efficiency.
Dr. P. Veeramani, Agricultural Science Center, Virinjipuram, Vellore – 632 104
