Drip Irrigation method, also called drop by drop irrigation, and underground irrigation, functions as its name imply. Drop by drop, water is distributed to the active root zone of plants. This method, if managed properly, might be the most water-supply-efficient way of irrigation, because runoff and evaporation reduced significantly.
Drip irrigation in today’s agriculture, is frequently integrated with plastic sheet, further diminishing evaporation, and is also a method of fertilizers delivery to the plants. This process called fertigation (fertilizer + irrigation).
Drip irrigation is most suitable for row crops (vegetables, soft fruit), tree and vine crops where one or more emitters can be provided for each plant. Generally only high value crops are considered because of the high capital costs of installing a drip system.
Here’s why plants are more productive with drip irrigation:
- High availability of water and nutrients
- Doses of water and nutrients tailored to plant’s development needs
- No saturation and good soil aeration
- Avoids high salinity caused by excessive fertilizer application
- No wetting of foliage that can result in fungal diseases
- Fertilizer and nutrient loss is minimized due to localized application and reduced leaching.
- Water application efficiency is high if managed correctly
- Field leveling is not necessary.
- Fields with irregular shapes are easily accommodated.
- Recycled non-potable water can be safely used.
- Moisture within the root zone can be maintained at field capacity.
- Soil type plays less important role in frequency of irrigation.
- Soil erosion is lessened.
- Weed growth is lessened.
- Water distribution is highly uniform, controlled by output of each nozzle.
- Labour cost is less than other irrigation methods.
- Variation in supply can be regulated by regulating the valves and drippers.
- Fertigation can easily be included with minimal waste of fertilizers.
- Foliage remains dry, reducing the risk of disease.
- Usually operated at lower pressure than other types of pressurised irrigation, reducing energy costs.
- Expensive initial cost can be more than overhead systems (commercial system)
- The sun can affect the tubes used for drip irrigation, shortening their usable life
- If the water is not properly filtered and the equipment not properly maintained, it can result in clogging
- Drip irrigation might be unsatisfactory if herbicides or top dressed fertilisers need sprinkler irrigation for activation
- Waste of water, time & harvest, if not installed properly.
Systems require careful study of all the relevant factors like land topography, soil, water, crop and agro-climatic conditions, and suitability of drip irrigation system and its components
- Without sufficient leaching (most drip systems are designed for high efficiency, meaning little or no leaching fraction), salts applied with the irrigation water may build up in the root zone