Drip Irrigation
From Swikipedia
Introduction
Drip irrigation is an irrigation method which saves 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. This process is also called trickle irrigation or micro-irrigation.
Brief Description
Working of Drip Irrigation System:
Drip irrigation systems consist of emission devices serviced by a water distribution network that includes control zone equipment. At the water source, water is controlled with automatic valves, sometimes amended with nutrients or chemicals, filtered and regulated at levels suitable for the emission devices chosen and plants being grown. From there, water is delivered to each of the emission devices through a network of PVC and PE pipes. The emission device, whether it is drip tape, a drip emitter, jet or micro-sprinkler, then delivers water and nutrients to the soil where plant roots may nourish the plant. All components have attributes that affect performance, and that are traded off with initial, installation, operation and maintenance costs.
Advantages:
• Minimized fertilizer/nutrient loss due to localized application and reduced leaching
• High water application efficiency
• 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
Disadvantages:
• Initial cost can be more than overhead systems
• The sun can affect the tubes used for drip irrigation, shortening their usable life. Longevity is variable
• 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
• 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
• In lighter soils subsurface drip may be unable to wet the soil surface for germination. Requires careful consideration of the installation depth
• Most drip systems are designed for high efficiency, meaning little or no leaching fraction. Without sufficient leaching, salts applied with the irrigation water may build up in the root zone, usually at the edge of the wetting pattern.
References:
http://en.wikipedia.org/wiki/Drip_irrigation
