Here is a term paper on ‘Drip Irrigation’ for class 7, 8, 9, 10, 11 and 12. Find paragraphs, long and short term papers on ‘Drip Irrigation’ especially written for school and college students.
Term Paper on Drip Irrigation
Term Paper Contents:
- Term Paper on the Definition of Drip Irrigation
- Term Paper on the Types of Drip Irrigation
- Term Paper on the Components of Drip Irrigation System
- Term Paper on the Design of Drip Irrigation System
- Term Paper on the Installation of Drip System
- Term Paper on the Operation and Maintenance of Drip Assembly
- Term Paper on the Advantages of Drip Irrigation
- Term Paper on the Disadvantages of Drip Irrigation
- Term Paper on the Extent of Drip Irrigation
Term Paper # 1. Definition of Drip Irrigation:
Drip irrigation is an advanced method of application of water to the crops. This micro irrigation system has found greater acceptability not only world over but also in our country among the progressive farmers in recent years, especially in water scarcity areas like arid lands and deserts. As the name suggests, in this system water is applied directly through nozzles at the roots of the plants at a very slow rate drop-by-drop or in trickles. Therefore, it is also called trickle irrigation.
In this method water is conveyed to the field through small diameter tubings, (diameter may be say 1 to 2 cm) fed from larger size feeder tubes. The nozzles are attached to tubings which are laid at the roots of plants either on surface or underground suitably. Fertilizers, pesticides etc., are added to the irrigation water before the water trickles down at plant roots.
Since the water is applied in the root zone of a crop, water soaks into the soil before it is lost by evaporation or wasted as run-off. Therefore these losses are absolutely negligible. Also since the water is applied drop-by-drop it is sufficient to just meet crop water needs and therefore, percolation loss is also are minimum. It makes this system of irrigation very useful in desert soils as well as saline soils.
Drip irrigation helps in keeping surrounding water content of the plants in the soil mass in optimum range which could be nearly somewhat like field capacity. Depending upon type of system used, drip irrigation saves 25% to 60% water.
It is estimated that efficiency of drip irrigation system is as high as 90 percent. For this reason drip irrigation is a preferred method of irrigation in desert areas of Israel and U.S.A. and other developed countries. Under drip irrigation increases in yield of about 60 to 70 percent on an average have been reported. Also, input cost of fertilizers, weedicides, pesticides, power and water have also been found to decrease by as much as 30 percent.
In short, drip irrigation performs three functions:
(i) It minimizes irrigation water loss by preventing evaporation and percolation on fields.
(ii) It increases crop yield; and
(iii) It economises in use of fertilizers, weedicides and pesticides.
Term Paper # 2. Types of Drip Irrigation:
Manufacturers claim drip irrigation is easy to install, easy to design, can reduce diseases associated with high level of moisture and therefore useful almost anywhere. In the market there are various systems useful for growing apples, tea, coffee, mango, as also for crops like sugarcane, cotton. Flowers, vegetables, grapes are known to be suitable for receiving irrigation by drip system. In fact farmers have been successfully using drip irrigation for horticulture crops such as grapes, pomegranate, mango, banana, guava, coconut, amla and cash crops such as sugarcane.
From the variety of crops to be irrigated by drip irrigation it is clear that requirement of crops cannot be fulfilled by a single drip assembly uniformly. Based on detailed study of inter relationship among soil-water-crop, land terrain and related agro-climatic conditions a suitable and economically viable system to deliver a measured quantity of water at the root zone of each plant at regular intervals has to be designed.
This ensures that the plants do not suffer from too less or over-watering. There are, therefore, various types of drip assemblies in existence ranging from simple bucket kit system to automated drip irrigation system.
Some of the drip irrigation systems in practice are:
(i) Bucket kit drip irrigation system.
(ii) In-door drip irrigation system.
(iii) Gravity drip irrigation system.
(iv) Lawn drip irrigation system.
(v) Automatic drip irrigation system.
(vi) Farm drip irrigation system.
Each farmer has to select a particular type of drip system to suit his irrigation needs.
Term Paper # 3. Components of Drip Irrigation System:
A drip irrigation system basically requires flexible micro-tubings as well as poly-tubings and PVC pipes suitably fitted with nozzles to deliver water to individual plants. Also needed are filter and pressure regulator to clean the water of suspended impurities and a device to maintain desirable head to permit flow of water respectively.
Arrangement to mix fertiliser, pesticides, weedicides and control application of water is also necessary. Depending upon status of the assembly clockwork, valves, backflow prevention assembly, automation devices are included in a particular drip system. In short a drip assembly can be said to consist of head-work, water conveyance network and control system.
Since each drip system is designer type to suit farmer’s requirement there can neither be standard components kit nor a rigid or predetermined arrangement of the components in the drip assembly. In other words drip irrigation system is a customized product to suit individuals’ needs. A list of the components that make a drip system and their functions is mentioned.
(a) Head Work:
(i) A pump to lift water or a hydrant to force water and to create pressure.
(ii) Head tank to store water as well as to create water pressure. Water head may vary according to requirement of a farmer.
(iii) Fertilizer, weedicide and pesticide mixing arrangement. It ensures that irrigation water contains appropriate doses of these nutrients.
(iv) Filter, Irrigation water passes through filter which removes suspended impurities from the water. With provision of filter, nozzles which have small perforations do not get clogged.
(v) Pressure regulator; it regulates pressure of the flowing irrigation water.
(b) Water Conveyance Network:
(i) Mains and Sub-Mains or Pipes and Tubings:
Mains are P.V.C. pipes of appropriate diameter which convey water from the source of water supply to the drip irrigation area. Sub-mains or poly-tubings divert water in different directions in the field. These pipelines or tubings are made of P.V.C. (Polyvinyl chloride) or polyethylene or alkaethylene material. They are laid on the surface or underground.
(ii) Laterals or Trickle Lines:
These flexible poly-tubings are 10 to 13 mm diameter tubes made of polyethylene material and branch off from Sub-mains. They carry water along the row of crop or trees or plants. They are usually 50 metres in length and are fitted with flush or end cap. Their spacing on the sub-mains is so adjusted that for each row of crop or trees a lateral runs alongside.
(iii) Nozzle or Emitter and Micro-Tubings:
An emitter has perforations to release water at the plant’s root zone drop-by-drop and water released may vary from 2 to 10 litres per hour depending upon requirement of a crop.
The emitters are fixed on the laterals at appropriate intervals to supply the water at the root of the plants or crops to be grown. Sometimes a smaller micro-tubing can be attached to the lateral or tubing which run out to the individual plants. At the end of each micro-tubing an emitter is attached which regulates the water flow.
(iv) Valve or Discharge Regulator:
It is provided on the sub-main at a junction from where a lateral takes off. Capacity of the valve is fixed in accordance with the size and number of emitters or nozzles used on a lateral. The automatic valve at the head of the lateral is adjusted to deliver a measured quantity of water and supply stops automatically thereafter.
(v) End or Flush Cap:
It is fitted at the end of laterals to prevent wastage of water or to flush the pipe network.
(c) Control System:
(i) Irrigation clock.
(ii) Electric control valve.
(iii) Back flow prevention device.
(iv) Programmable timer.
(v) Tensiometers.
Above mentioned components of control system may be installed to regulate automated operation of a drip system as per requirement of a customer.
Term Paper # 4. Design of Drip Irrigation System:
Design of a drip irrigation system is very important aspect in adoption of the system not only because irrigation schedule depends upon it but also because it is customized to suit land topography, soil type, type of water source, desired cropping pattern and agroclimatic conditions. In short, it is something like turn-key irrigated agricultural development scheme desired by a farmer.
In India there are manufacturers which not only supply drip irrigation kits but also offer agronomic and extension support in addition to after sales services and technical support to enable a farmer to reap bumper crop in most economic manner. “Jain Irrigation Systems Ltd” of Jalgaon, Maharashtra state is one such name who specializes in manufacture and installation of drip irrigation systems.
While designing a drip irrigation system, in addition to selection of components of a proposed drip irrigation assembly, following aspects need careful consideration:
(a) Type of plants or crops to be grown and their watering needs.
(b) Topography of Land:
It will decide how to lay the network of pipes whether over-ground or underground. Even if a part of the network is to be buried it is useful to lay the pipe line above ground initially to ensure that selection of alignment is most suited for the given topography. Then while installing the drip assembly required part of pipe line can be buried.
(c) Type of Soil:
While in clayey soils more pressure is to be maintained, in sandy soils pressure has to be less to avoid deep percolation. It will decide choice of related components.
(d) Water Requirements:
It will decide locations of joints and connectors and types of emitters to be used.
Term Paper # 5. Installation of Drip System:
Schematic diagrams of drip irrigation system are given at Figs. 12.1 and 12.2 which illustrate the system lucidly for a field crop and gardens respectively.
Various steps involved in installation are the following:
(i) From a source of water lay a PVC pipeline of appropriate size to the irrigation area.
(ii) Locate a back flow prevention assembly immediately below the source on the pipeline to stop back flow of chemically laden water into the source. Irrigation water in drip system contains chemical fertilizers, weedicides and pesticides which are harmful to human beings.
(iii) Take the pipeline to valve box or pump house.
Valve box includes valves, filter and pressure regulator. It may be above ground or buried underground as per site conditions.
If pump is used to pump water into a storage tank for creating head, from an elevated tank water is taken through fertilizer mixer assembly. Thereafter water is taken through filter to eliminate suspended impurities from water to avoid clogging of emitters.
(iv) Along the already decided alignment dig trenches starting from valve box as required after taking soil type and slope of land into consideration. The trenches may be 10 cm deep unless soil is sandy. Backfill the trenches to give protective cover to pipes and tubings and electrical wiring. However, it is necessary to keep drip emitters above the ground so that chances of getting them clogged by minute soil particles, is avoided.
(v) PVC pipes (1/2 inch or 1.3 cm dia), polyethylene tubings and laterals may be laid above ground or buried as considered necessary.
(vi) Attach irrigation clock on the main or bury it in the valve box. The wires from irrigation clock to valves can run along with the sub-mains in the trenches. The valves are provided on the sub-mains to control discharge of water into lateral tubings or on the main as per requirement.
(vii) Emitters are connected appropriately to poly-tubings or laterals and where necessary to micro tubings to take water to individual plants.
(viii) According to irrigation needs of crops select number and type of emitters. Also make sure that joints and connectors are appropriately placed to enable proper watering of crop roots.
(ix) At the end of laterals provide end or flush caps.
Term Paper # 6. Operation and Maintenance of Drip Assembly:
The operation of drip assembly is governed by watering schedule of a crop. Number of days drip system has to work at a stretch and the frequency thereof depends on the type of soil and the crops to be watered. The number of nozzles (emitters) to be placed on each valve depends upon the rate of flow of watering system.
During operation if the plants seem to be drooping, subsoil moisture has to be checked. The flow of water then accordingly increased. On the other hand if soil appears to be wet then the plants may have received over watering. In such a situation flow through nozzles need adjustment.
If the soil is seen to be dry there is likelihood that some nozzles are clogged. To avoid such problems during operation of the system, pipe network as well as filter should be flushed every-time irrigation schedule is changed. During flushing, end or flush caps fitted on laterals or poly-tubings have to be removed to flush sediment out of the drip assembly.
Term Paper # 7. Advantages of Drip Irrigation:
Drip irrigation has following advantages:
(i) Drip irrigation is the most efficient method of irrigation. It is found that drip irrigation has about 90% efficiency.
(ii) The high efficiency of the system is a result of two primary advantages. Firstly, evaporation losses or run-off is the minimum. Secondly, percolation losses are also the minimum as compared to other methods of irrigation.
(iii) Drip irrigation enables supplying optimum quantity of water, which is very close to field capacity, to the crops.
(iv) By adopting this system nearly 60% to 70% extra yield is possible than the average yield.
(v) Since just sufficient water is supplied to root zone of crops there is no chance of land getting waterlogged.
(vi) In the absence of superfluous flow of irrigation water weed growth is minimum. It results in saving of farm labour charges.
(vii) With the water saved by using drip irrigation, extra land can be brought under irrigation with the allocated water supply to a farmer.
(viii) In drip system of irrigation there is nearly 30% economy in use of fertilizers, weedicides and pesticides.
(ix) The problem of land erosion is totally avoided.
(x) It is most preferred method of irrigation on saline and desert soils.
(xi) In this method rate of application of water can be changed anytime during the crop period to suit crop water requirement.
(xii) The watering is done in a scientific manner in contrast to other traditional surface irrigation methods.
(xiii) It makes possible to grow cash crops and fruits and flowers in a controlled environment thereby increasing productivity of a farmer.
Term Paper # 8. Disadvantages of Drip Irrigation:
Drip irrigation has following disadvantages:
Every system has some constraints. Drip irrigation has following disadvantages:
(i) Initial procurement and installation cost is high. Therefore, for poor farmers with small land holdings, it is difficult to get this system installed on their fields.
(ii) There are number of loose parts and they need very careful and meticulous maintenance.
(iii) This system is not as robust as other methods of irrigation. With change in crop or in different crop seasons, the position of laterals and emitters, have to be changed. Frequent change or handling of parts may cause them damage.
(iv) There is likelihood of development of shallow roots in horticultural crops. In such a situation the plants have less anchorage in the soil. It may result in felling of trees or plants during hailstorm or high winds.
Term Paper # 9. Extent of Drip Irrigation:
Out of estimated 69 million hectares (Mha) net irrigated area in the country at the beginning of the XI Plan (2007-12), drip irrigation covers only 0.5 Mha or five lakh hectares. Maharashtra State leads the list of users of drip irrigation system. Starting from mere 16,000 hectares at the end of VII Plan (most of which was in Maharashtra State) the country has reached 5 lakh hectare mark at the end of X Plan.
Everywhere similarly advanced drip system is not in use. Drip irrigation methods range from simple bucket kit systems for small farms to automated drip systems, linking releases of water to soil moisture conditions measured continuously by tensiometers.
Realizing that micro irrigation has the potential to transform Indian Agriculture, Central Government is giving thrust to extend micro irrigation system in the country and has impressed upon the State Governments to consider and enforce various suggestions made by the task force on micro irrigation. One of the impressive suggestions is to make it compulsory to allocate 10% of command area in a project for adoption of micro irrigation method.