Drip irrigation, also known as trickle irrigation or microirrigation is an irrigation method which minimizes the use of water and fertilizer by allowing water to drip slowly to the roots of plants, either onto the soil surface or directly onto the root zone, through a network of valves, pipes, tubing, and emitters.
Modern drip irrigation has arguably become the world's most valued innovation in agriculture since the invention of the impact sprinkler in the 1930s, which replaced flood irrigation. Drip irrigation may also use devices called micro-spray heads, which spray water in a small area, instead of dripping emitters. These are generally used on tree and vine crops with wider root zones. Subsurface drip irrigation (SDI) uses permanently or temporarily buried dripperline or drip tape located at or below the plant roots. It is becoming popular for row crop irrigation, especially in areas where water supplies are limited or recycled water is used for irrigation. Careful study of all the relevant factors like land topography, soil, water, crop and agro-climatic conditions are needed to determine the most suitable drip irrigation system and components to be used in a specific installation.
Advantage / Disadvantages of Drip Irrigation
The advantages of drip irrigation are:
Minimized fertilizer/nutrient loss due to localized application and reduced leaching.
High water application efficiency.
Leveling of the field not necessary.
Ability to irrigate irregular shaped fields.
Allows safe use of recycled water.
Moisture within the root zone can be maintained at field capacity.
Soil type plays less important role in frequency of irrigation.
Minimized soil erosion.
Highly uniform distribution of water i.e., controlled by output of each nozzle.
Lower labour cost.
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 thus reducing the risk of disease.
Usually operated at lower pressure than other types of pressurised irrigation, reducing energy costs.
The disadvantages of drip irrigation are:
Expense. Initial cost can be more than overhead systems.
Waste. The sun can affect the tubes used for drip irrigation, shortening their usable life. Longevity is variable.
Clogging. 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 fertilizers need sprinkler irrigation for activation.
Drip tape causes extra cleanup costs after harvest. You'll need to plan for drip tape winding, disposal, recycling or reuse.
Waste of water, time & harvest, if not installed properly. These systems requires 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.
Germination Problems. In lighter soils subsurface drip may be unable to wet the soil surface for germination. Requires careful consideration of the installation depth.
Salinity. High application efficiency often results in a failure to meet the leaching requirement, therefore salts build up in the root zone. This is a significant problem in areas where seasonal rainfall is not sufficient to drain salts from the profile.
