Water though cherished. is one of the scarce resources required for nutrient grain production in our state. Every attention should be taken to use this resource expeditiously. Choice of an appropriate method of irrigation based on harvest and dirt type is a requirement for efficient use of H2O. It besides helps in heightening and prolonging dirt productiveness in the long tally. Assorted methods of irrigation have been comprehensively discussed in this brochure. Fictional characters of an efficient method of irrigation. factors impacting the suitableness of an irrigation method and cultural patterns for increasing H2O usage efficiency have besides been briefly highlighted.
Dr. K. T. Chandy. Agricultural & A ; Environmental Education.
Water is an of import component of the works organic structure. Plants need H2O to transport on different physiological procedures indispensable to their growing and development. A great trade of H2O from works organic structure is wasted through the procedure of transpiration. Therefore. to counterbalance this loss of H2O. soaking up of H2O from dirt is an of import phenomenon. Soil gets H2O chiefly from two beginnings viz. precipitation and irrigation.
Hence. irrigation is a procedure. other than natural precipitation. which supplies H2O to harvests. groves. grass. or any other cultivated. workss. In the wetting agent parts of the universe where rainfed cultivation is practiced. the farmer’s activities consist of choosing suited land. fixing the dirt for cultivation ; seeding. be givening and reaping the harvests. Natural rainfall provides the H2O needed. But in many other topographic points otherwise favorable for cultivation. natural rainfall does non supply all the H2O needed and. as such. irrigation of harvests is required to do up this lack.
Techniques adopted for transporting H2O from its beginning to the harvest are called methods or manners of application. These are:
1. deluging -wetting all the land surface ;
2. furrows -wetting merely certain portion of land degree ;
3. sprinkler -in which the dirt is wetted in much the same manner as rains ; 4. sub-surface irrigation -in which surface is wetted really lightly. but the sub dirt is to the full saturated ; and 5. localised irrigation -in which H2O is applied at each person works at. a close day-to-day rate.
II. Characteristics of an Efficient Irrigation Method
An efficient method of irrigation should carry through five major aims viz. ( 1 ) distribution of H2O uniformly over the field harmonizing to harvest demand. ( 2 ) storage of maximal fraction of H2O in the root zone for works usage. ( 3 ) harvest growing should non be adversely affected. ( 4 ) dirt conveyance or loss is negligible. and ( 5 ) the technique used is economically sound and adoptable at the farm.
III. Factors Affecting Suitability of Irrigation Method
The choice of a suited irrigation method for a peculiar farm location depends upon the undermentioned factors.
Textural. crusting. snap and infiltration features of surface dirt ; nature and deepness of comparatively impermeable beds in sub-soil. if any ; H2O storage capacity of root zone ; nature and extent of land incline ; size of field ; surface drainage ; nature and extent of salts in surface and sub-soil are the outstanding dirt factors act uponing between of an irrigation method. 2. Water
Nature of H2O supply ( uninterrupted or rational ) . beginning ( pump or canal ) . size of H2O bringing. quality of irrigation H2O. and measure of H2O supply ( equal or limited ) country few factors that must be taken into consideration while make up one’s minding the method of irrigation.
Nature of harvests. country under different harvests and their rooting behavior. optimal deepness and timing of irrigation. sensitiveness of harvests to excessive dirt wet. cultural operations required. etc. must be considered at the clip of choice of irrigation method for a harvest.
There are other factors act uponing irrigation method like mentality. managerial efficiency and fiscal resources of the husbandman ; nature of the farm machinery used ; handiness and cost of labor ; wear and tear care installations and costs of irrigation equipments ; and handiness of power supply. Equally far as possible. an irrigation method should non merely supply a high degree of H2O application efficiency. but besides guarantee its economic viability. sustained dirt productiveness and wide’ adaptability to prevailing characteristic of the farm. Generally. irrigation methods followed in India deficiency in an economic usage of irrigation H2O.
IV. Methods of Irrigation
Methods of irrigation. by and large adopted in India. can be represented in the flow chart.
Methods of Irrigation
A. Surface irrigation
In this method. H2O from an irrigation channel is allowed to make a portion or whole of the field and spread by the gravitative flow minor expense to the incline of the land. Water may be distributed to the harvests in boundary line strips. look into basins or furrows. The of import demands to obtain high efficiency in surface method are ( 1 ) decently constructed H2O distribution systems to supply equal flow of H2O to the Fieldss ; and ( 2 ) proper rating and grading of land to accomplish unvarying distribution of H2O.
1. Surround strip method
The boundary line method of irrigation makes usage of parallel ridges to steer a sheet of fluxing H2O as it moves down the incline. The land is divided into a figure of long parallel strips called boundary lines that are separated by low ridges. The boundary line strip has little or no cross incline but has a unvarying soft incline in the way of irrigation. The indispensable characteristic of boundary line irrigation is to supply an even surface over which the H2O can flux down the incline with a about unvarying deepness. Each strip is irrigated independently by turning into a watercourse of H2O at the upper terminal. The H2O spreads and flows down the strip in a sheet confined by the boundary line ridges. The irrigation watercourse must be big plenty to distribute over the full breadth between the boundary line ridges without over exceeding them. When the progressing H2O forepart either reaches the lower terminal. or a few proceedingss before or after that. the watercourse is turned off.
The H2O temporarily stored in the boundary line moves down the strip and infiltrates into the dirt. therefore finishing the irrigation. It is adapted to most dirts where deepness and topography license. 1 the needed land grading at a sensible cost and without any! lasting decrease in dirt birthrate. It is. nevertheless. more suited to dirty holding reasonably low to reasonably high infiltration rates. It is by and large non used in harsh sandy dirts that have really high infiltration rates. It is besides non good suited to dirty holding a really low infiltration rate. This method is suited to water all close turning harvests like wheat. barley. fresh fish harvests and leguminous plants. It is. nevertheless. non suited for harvests like rice which requires standing H2O during most portion of its turning season.
I. It is easy to build boundary line ridges even with some simple farm implements like a bullock drawn A-frame ridger or tractor-drawn phonograph record ridger. two. Labour demand in irrigation is greatly reduced as compared to the conventional cheque basin method of irrigation. three. Uniform distribution and high H2O application efficiencies are possible if the system is decently designed. four. Large irrigation watercourses can be expeditiously used.
v. Operation of the system is simple and easy.
six. Adequate surface drainage is provided if mercantile establishments are available.
I. It requires an extended land rating which is excessively expensive. two. It is chiefly suited for deep dirts with the handiness of big flow of H2O. three. Drain may be indispensable.
four. Water wastage is often observed.
Straight and contour boundary lines
If the boundary lines are constructed along the general incline of the field. they are known as consecutive boundary lines or incline boundary lines. and if they are constructed across the general incline of the field they are called contour boundary lines. When Fieldss can be leveled to desirable land inclines economically and without impacting its productiveness. graded boundary lines are easier to build and run. In instance where land incline exceeds safe bound. Fieldss are rippling and grading is non executable. boundary lines may be laid across the incline. The design of a contour boundary line is the same as that of a consecutive boundary line. Each contour boundary line is flat crosswise and has a unvarying longitudinal gradient as in a consecutive boundary line. The breadth and length of a contour boundary line are indistinguishable to that of a consecutive boundary line for a peculiar set of conditions.
In puting contour boundary lines. the field is divided into a series of strips on the approximative contour. and each strip is leveled as an independent country. Thus. a series of strips are formed in consecutive lifts around the incline. The perpendicular interval between the next benches should. every bit far as possible. be limited to 30 centimeter. but should non transcend 60 centimeter. The tallness of ridge should be sufficient to look into both the normal irrigation watercourse and run-off.
2. Check basin irrigation
Check basin irrigation is the most common method of irrigation in India and in many other states. This is the simplest in rule of all methods of irrigation. There are many systems in its usage. but all involve spliting the field into smaller units so that each has a about flat surface. Ridges-are-constructed around the countries organizing basins within which the irrigation H2O can be controlled. The basins are filled to the desired deepness and the H2O is retained until it infiltrates into the dirt. The deepness of H2O may be maintained for considerable periods of clip by leting the H2O to go on to flux into the basins.
The distinguishing characteristics of assorted utilizations of cheque basin method of irrigation involve the size and form of the basins and ” whether irrigation is accomplished by intermittent or continuous” aggregation of H2O in the basins. The ridges or bunds may be impermanent for a individual irrigation as in the pre-sowing irrigation of seasonal harvests. They may be semi-permanently constructed for the repeated usage in the instance of Paddy Fieldss. The size of ridge will depend on the deepness of H2O to be impounded every bit good as on the stableness of the dirt when moisture.
Water is conveyed to the field by a system of supply channels and sidelong field channels. The supply channel is aligned on the upper side of
the country and there is normally one sidelong channel for every two rows of cheque basins. Water from the laterals is turned into the beds and is cut off when sufficient H2O has been administered into the basin. Water is retained in the basin until it soaks into the dirt. The size of the irrigation watercourse is non critical every bit long as it is sufficient to supply a coverage of the full strip in a comparatively short clip span required to use the coveted sum of H2O into the dirt. As the infiltration rate of dirt additions. watercourse size must be increased or the size of the basins reduced in order to cover the country within a short period of clip. A big size irrigation watercourse will allow a relatively larger size of the basin.
The size of cheque basin may change from one square meter. used for turning veggies and other intensive cultivation. to every bit big as two hectares or more. used for turning rice under wet land conditions. When the land can be graded economically into about flat Fieldss. the basins are rectangular in form. In turn overing topography the ridges follow the contours of the land surface. The contour ridges are connected by cross ridges at intervals. The perpendicular interval between contour ridges normally varies from 6 to 12 centimeter. in instance of highland irrigated harvests like wheat and 15 to 30 centimeter in instance of low land irrigated harvests.
In watering groves. square to contour basins may be used as in other harvests. When the workss are widely spaced the pealing method of basin irrigation is adopted. The rings are round basins formed around each tree. The ring basins are little when the works is immature. The size is increased as the works grows.
Check basin irrigation is suited to smooth. soft and unvarying land inclines and for dirts holding moderate to decelerate infiltration rates. Steep inclines require complex layouts and heavy land grading. Both row harvests every bit good as close turning harvests are adapted to basins every bit long as the harvest is non affected by impermanent flood. The method is particularly adopted for. irrigation of grain and fresh fish harvests in heavy. dirts where H2O is absorbed really easy. It is besides suited in really permeable dirts which must be covered with H2O quickly to forestall one inordinate deep infiltration loss of H2O at the upstream terminal.
I. Since in this method the full country is non flooded. it ensures -high H2O usage efficiency. two. Excessive ooze loss can be avoided by following this pattern three. Damage to workss and loss of dirt foods do non happen in this pattern: . .
I. The major disadvantage of cheque basin method of irrigation is that the ridges interfere with the motion of carnal drawn or tractor drawn implements for inter civilization operations or harvest home of harvests. two. Considerable land is occupied by ridges and sidelong field channels and harvest outputs are well reduced. three. The method impedes surface drainage.
four. Precise land scaling and determining are required.
v. Labour demand in land readying and irrigation are much higher.
3. Furrow irrigation
The furrow method of irrigation is used in irrigation of row harvests with furrows developed between the harvest rows in the planting and cultivating procedures. The size and form of the furrow depends on the harvest grown. equipment used and spacing between harvest rows. Water is applied by running little watercourses in furrows between the harvest rows. Water infiltrates into the dirt and spreads laterally to. water the countries between the furrows. The length of clip H2O takes to flux in the furrows depends on. the sum of H2O required to refill root zone and the infiltration rate of the dirt. Both big and little irrigation watercourses can be used by seting the figure of furrows irrigated at anyone clip to accommodate the available flow. In countries where surface drainage is necessary. the furrows can be used to dispose off the run-off from rainfall quickly.
Furrow irrigation can be used to water all cultivated harvests planted in rows. including groves and veggies. Among the common cultivated harvests of India. the method is suited for watering corn. sorghum. sugar cane. cotton. baccy. Indian potato. murphy and other veggies. Furrows are peculiarly good adapted to watering harvests which are capable to injury from accrued surface H2O or susceptible to fungal root putrefaction. Furrow irrigation is suited to most dirts except littorals that have a really high infiltration rate and supply hapless sidelong distribution of H2O between furrows.
I. Water in the furrows contacts merely one half to one fifth of the land surface. thereby cut downing puddling and crusting of the dirt. and vaporization losingss. two. Early sowing is possible which is a distinguishable advantage in heavy dirts. three. It can be safely adopted on the sloppy lands by opening the furrows across the incline. four. This. method reduces labour demand in land readying and Irrigation. v. Compared to look into basin method. there is no wastage of land in field ditches.
I. It requires skilled laborers to run. .
two. It may do serious eroding. if extra H2O flows over the ridges. three. Difficult to transport on mechanical operations.
Irrigation furrows may be classified into two general types is based on their alliance. They are ( one ) straight furrows. ( two ) contour furrows. Based on their size and spacing furrows. may be classified as deep furrows and corrugation.
a. Deep furrows
As mentioned above. deep furrows are of two types i. e. consecutive furrows and contour furrows.
I. Straight furrows
Straight furrows. like boundary lines. are laid down across the prevailing land incline. They are best suited to sites where the land incline does non transcend 0. 75 per cent. In countries of intense rainfall. nevertheless. the furrow class should non transcend 0. 5 % so as to understate the eroding jeopardy.
two. Contour furrows
Contour furrow method is similar to the graded furrow method in that the irrigation H2O is applied in furrows. but the furrows carry H2O across the inclining field instead than down the incline. Contour furrows are curved to suit the topography of the land. The furrows are given soft incline along its length as in the instance of ranked furrows. Field supply channels rundown the land incline to feed the single furrows and are provided with eroding control structures.
b. Corrugation irrigation
Corrugation irrigation consists of running H2O in little I: furrows. called corrugatio’1s which direct the flow down the incline. It is normally used for watering non-cultivated close turning harvests such as little grains and for grazing land turning on steep inclines. Corrugation may be used in concurrence with boundary line irrigation on lands with comparatively level inclines in order to acquire unvarying coverage with H2O. The H2O is applied to little furrows and the harvest rows are I non needfully related to the irrigation furrows. In this method the dirt may be prepared and the harvest program without respect for irrigation layout After the seed is seeded. but before the sprouting has taken topographic point. a corrugation is used doing little furrows or corrugation to assistance in commanding irrigation H2O. The corrugation may be used with a simple bamboo corrugators or agriculturists equipped with little furrowers or other similar implements. Corrugations are V -shaped or U shaped channels about 6 to 10 centimeters deep. They are separated 40 to 75 centimeters apart. The full dirt surface is wetted easy by the capillary motion of the H2O which flows in the corrugations.
This method of irrigation is the most suited in loamy dirts in which the sidelong motion of H2O occurs readily. Clay dirt holding hapless infiltration capacity are rather unsuitable for irrigation by corrugations. This method is besides non suited for irrigation in deep sandy dirts due to inordinate loss of H2O by deep infiltration before the full dirt surface is wetted.
Saline solution or alkaline dirts or irrigation H2O holding salt content is non suited for this method because of the danger of salt accretion on surface dirts due to capillary motion of H2O.
i. Corrugation irrigation minimizes the crusting consequence on the surface dirt which may happen when the full surface is flooded.
two. High H2O usage efficiency is ensured.
three. It can be used for shooting seeds which are drilled or broadcast in the dirt.
I. Not suited for a broad scope of dirts.
two. This is a labour intensive method.
three. If the corrugations are placed across the land incline. the over flow of H2O may travel down into the lower corrugations and may do terrible dirt eroding.
B. Sub-surface irrigation
In this method of irrigation H2O is applied below the land surface by keeping an unreal H2O tabular array at some deepness depending upon the dirt texture and the deepness of the works roots. Water reaches the works roots through capillary action. Water may be introduced through unfastened ditches or under land grapevines such as tile drains or mole drains. The deepness of unfastened ditches varies from 30 to l00cm and they are spaced about 15 to 30 meters apart. This H2O application system consists of field supply channels. ditches or trenches and drainage ditches for the disposal of extra H2O. The irrigation ditches should be appropriately spaced to cover the whole field adequately.
This method is suited to dirty holding moderately unvarying texture and are permeable plenty for H2O to travel quickly both vertically every bit good horizontally within and for some distance below the harvest root zone. The dirt profile must command a barrier against inordinate loss through deep infiltration. Topography must be smooth and about degree or little inclines really soft and unvarying.
1. In dirts holding low H2O capacity and a high infiltration rates. : where surface methods can non be used and sprinkler system: is really expensive. sub-surface irrigation method can be used efficaciously. Jemaah Islamiyah. Evaporation loss from land surface are minimal.
ailment. In this method. it is possible to keep the H2O degree at optimal dephs for harvests required at different growing phases.
I. It is rather expensive and labour intensifier in the beginning. two. The method requires an unusual combination of natural conditions. therefore its range is limited. three. Frequent remotion of accrued dirt and other stuffs from channels is necessary.
In India. this i1rigation is practiced to a limited extent for turning vegetable harvests around Dal Lake in Kashmir and for irrigation of coconut thenars in the organic dirts of Kuttanad country in Kerala.
C. Sprinkler irrigation
In the sprinkler method of irrigation. H2O is applied above the land surface as spray. The spray is developed by tlte flow of H2O under force per unit area through little openings or noses. The force per unit area is obtained by pumping with careful choice of nozzle sizes. operating force per unit areas and sprinkler spacing. High efficiency in H2O application/distribution can be obtained with sprinkler system. Sprinkler systems are of by and large two major types viz. ( I ) revolving caput system. and ( two ) perforated pipe system.
In instance of revolving caput system little noses are placed on riser pipes and these riser pipes are fixed at an even interval along the length of sidelong pipes which are placed on the land surface. However. they can be mounted on stations transcending the harvest tallness and made revolving through 90 grade. In revolving sprinkler. the most. of import device to revolve the sprinkler caput is a little cock activated by the trust of H2O striking the vane connected to it.
In instance of perforated pipe system. holes are perforated in sidelong irrigation pipes which is particularly designed to administer H2O with a good trade of uniformity. This system is normally designed for low operating force per unit areas ( i. e. 0. 5 to 2. 5 kg/sq centimeter ) . Due to this low force per unit area. the system is attached to an overhead armored combat vehicle to accomplish the needed force per unit area caput. The sprays are directed on both sides of the pipe which cover a strip of land from 6 to 15 meters broad.
About all arable dirts can be sprinkler irrigated. It is. nevertheless. non suited in really high textured dirts where the infiltration rates are really low ( i. e. less than 4 millimeters per hr ) . Most harvests demuring rice and jute can be sprinkler irrigated. The flexibleness of sprinkler equipment and efficient control of its application make this method adaptable to most of the topographic conditions. However. highly high temperature and air current speed markedly cut down the uniformity of H2O distribution and irrigation efficiency. This I system of irrigation is particularly utile to the dirts that have steep inclines or irregular topography and dirts which are excessively shallow to level.
I. This technique enables wise use of even little H2O flows and licenses efficient irrigation of undulated lands. and soils with shallow deepnesss. two. It saves 10to 16 % land that is used in building of channels and ridges in other methods. three. Highly permeable every bit good as comparatively less permeable dirts can be easy irrigated by sprinkler method without any hazard of run-off and eroding. flood and ooze losingss. four. Fertilizers. pesticides and weedicides can be applied along with H2O spray. therefore. salvaging excess labor.
I. High initial cost of equipments.
two. Operating costs are by and large higher than irrigation by surface methods. three. Winds disturb the sprinkler form giving uneven distribution of the irrigation H2O. four. Scattering with H2O incorporating an appreciable sum of salts may ensue in rotter or decease of the workss. v. Under certain climatic conditions diseases may be encouraged. The job of fruit decomposition in tomato and strawberry gets aggravated particularly in damp dirt status.
D. Localized irrigation
1. Drip irrigation
As the name signifies. trickle irrigation. besides termed as trickle irrigation. involves the slow application of H2O to the root zone of a harvest. The method was initiated in Israel and is now being tried in other states. In this method. H2O can be used really economically. since loss due to deep infiltration and surface vaporization are reduced to the lower limit. This method. therefore. is extremely suited to arid parts and orchard harvests. The successful elevation of groves even on saline dirts has been made possible by the trickle system of irrigation. The system can besides be used for using fertilisers in solutions.
In this system. H2O is applied more often. shut to the roots of workss through appropriately spaced drippers ( emitters ) attached to plastic or metallic pipes spread above or below dirts along harvest rows. The pipes are hooked to beginning of H2O supply through a storage armored combat vehicle or force per unit area device which provides necessary hydraulic caput or force per unit area for motion of H2O to the drippers. A pumping unit creates a force per unit area of approximately 2. 5kg/sq centimeter. In this instance merely a portion of dirt in the locality of works roots is wetted and kept near to field capacity. The sum of H2O dripping from noses can be regulated as desired by changing the force per unit area at the noses and the size of the opening of the noses. The initial high cost of the equipment and its care are the major restrictions in this system. It may. nevertheless. work out to be cheaper than the sprinkler system particularly for the groves and other widely spaced harvests.
2. Earthen pot irrigation
This method has been late developed by the Haryana Agriculture University. Hissar. It is really inexpensive and convenient method and can be easy adopted. In this method. foremost a cavity ( 60 centimeter deep and 90 centimeters broad ) is dug out and the earthen pot is embedded up to the cervix degree and so it is filled with H2O. The H2O is absorbed by the dirt through capillary action. One pot is sufficient to wash one square metre country. Care should be taken to cover the pot by lid and supply H2O from clip to. clip. The pots may be replaced by new 1s after two or three seasons. .
This system is particularly utile for watering vegetable harvests ego cucurbitaceous harvests grown in flaxen loam or sandy dirts.
I. It is the most suited method for vegetable and orchard harvests where workss are widely spaced.
two. It can be mly used in flaxen and undulating lands.
three. Saline H2O can be freely used because salts are deposited at the underside of the pot
four. High H2O usage efficiency.
v. A simple and relatively inexpensive method.
3. Double walled pot “Jaltripti”
It is a utile irrigation device for the desert. developed by the Central Arid Zone Research Institute ( CAZRI ) . Regional Station. Bikaner. It reduces the frequence and entire sum of H2O needed and ensures a regulated changeless supply of wet to corner workss for endurance and better growing.
This device consists of a dual walled earthen pot called “Jaltripti” ( H2O satisfaction ) . The diameter of the outer pot is kept. about 25 centimeter at the top and at base it is 18 centimeter. The diameter ; of inner pot is 15 centimeter on top and 12cm at base. The tallness is unbroken 30 centimeter. ( Since it is prepared on potter’s wheel. approximative dimensions have been given. Furthermore. some fluctuations in the measuring may happen ) . The dimensions of the inner pot have been kept somewhat bigger than the size of the polyethylene bags ( 25 centimeter long mensurating 10: centimeter across ) used for raising workss in baby’s room. Both the pots are joined together at the base and the radical part of interior pots is unbroken about unfastened. The external side of the outer pot is made imperviable with the degree Fahrenheit aid of pigment. cement or coaltar.
The “Jaltripti” maps on two simple rules:
1. Soil wet tenseness and works roots create a suction force which draws wet towards it from the adjacent high wet zone. two. Earthen pots have many micro-pores in their wall which do non let H2O to flux freely but let its ooze in the way where suction develops.
At the topographic point where planting has to be done. the device is fixed in the dirt in such a manner that the lip of the outer pot is above dirt surface. A tree sapling along with a dirt ball is transplanted in the inner pot The H2O is filled in the infinite between two pots and the round surface of H2O is caused by a polythene sheet to avoid direct vaporization of H2O. The pigment on the external surface of the pot prevents outward motion of H2O through ooze. But the suction force created by the inner pot allows for the ooze of H2O steadily in that way and keeps the dirt sufficiently moist for the I growing of the workss. Water is filled hebdomadal or biweekly depending upon the season and size of the pot. The device has been named ‘Jaltripti’ .
I. Economy of H2O ( 80 to 90 per cent ) .
two. It saves more H2O than trickle and sprinkler system.
three. Low irrigation frequence.
four. Labour economy.
v. No loss through infiltration. vaporization and ooze.
six. Regulated supply of wet. Moisture is ever available at field capacity.
seven. Promising in stabilisation of sand dune. .
Tueboponics is a reasonably recent development in the field of irrigation. This technique has been developed in Israel and practiced in the desert countries of that state in order to change over it into green exuberant woods.
In tueboponics. H2O is provided to plants/trees through injections. The acerate leaf is inserted into the works root and H2O is delivered into the bast. The needle and injection used for this intent are of particular form and design prepared merely for this intent.
In India. this technique has non yet arrived but it may turn out really utile in Indian deserves where H2O is really scarce. Its usage in harvest workss seems to be infeasible. It is a really simple device.
V. Drip and Sprinkler Irrigation in India: Constraints
India ranks foremost in regard of entire irrigated country bing in the universe. It has got about 80 million hectares of irrigated land. But the methods of irrigations employed are still really crude and inefficient. Recent accomplishments in the field of irrigation for case trickle and sprinkler irrigations are yet non sufficiently popular in India.
More than 10 million hectare is irrigated by sprinkler method and I million hectare by drip irrigation in the universe. But in India. it is merely approximately 0. 7 m. hour angle under sprinkler irrigation and less than 20. 000 hour angle with drip irrigation. Therefore. it is necessary to popularise these advanced methods of irrigation particularly in those countries where H2O is a scarce resource.
India is blessed with abundant H2O resources. However. the available H2O. peculiarly for irrigation is be givening to decrease and at the same clip its demand is soberly felt due to population detonation. The emerging challenge is to tap all the available resources of H2O.
Technological inventions are to be exploited to accomplish the duplicate aims of higher productiveness and better H2O usage efficiency. For this. we will hold to popularise trickle and sprinkler irrigation methods. On history of certain fiscal. proficient and institutional restraints. these methods have non got their due topographic point in India and accordingly. the country benefited is negligible. Therefore. the inquiry arises as to what are the restraints and jobs keeping up advancement.
The followers are the major restraints faced by the husbandmans in following the trickle and sprinkler systems of irrigation.
1. High initial cost.
2. Inadequate subsidy sum.
3. Trouble in acquiring subsidy sum
4. Lack of handiness of proficient input and after sale services.
5. Clogging of dripper and snap of laterals.
6. Damagess due to rats and squirrels.
7. High cost of spares and constituents.
8. Discrimination in subsidy distribution among different classs of husbandmans.
To work the full potency of these two inventions. the restraints are to be overcome by appropriate policy instruments. fiscal support and proficient counsel. This calls for an incorporate attack and enterprise on the portion of authorities. Implementing bureaus. rnanufacturing cornpanies. voluntary organisations and the ultimate users of the systems i. e. the husbandmans.
VI. Adverse Effect of Improper Irrigation
As H2O is a limited resource with no replacement. its efficient and wise use is of extreme importance in prolonging and increasing agricultural production. If irrigational H2O is used inefficiently and unscientifically. it may do certain inauspicious effects. instead than being utile. to the harvest and dirt.
Seepage from chief and branch canals. distributaries. and field channels along with the deep drainage loss from the base and cropped Fieldss due to heavy rains and over irrigation attention deficit disorder to the land H2O and cause rise of H2O tabular array. If non checked. the H2O tabular array may lift near to the surface and cause H2O logging of dirt. If here is a salty bed in the dirt. the salts may acquire dissolved in the lifting H2O tabular array and come up on the surface dirt thereby rendering the dirt less productive due to salt. Soil aeration is besides severely affected.
Rising of H2O table beyond the threshold deepness can be prevented by supplying needed sub-surface drainage. Alternatively. in countries with good quality land H2O. radial drainage with shallow pumps and recycling the H2O for irrigation can be practiced with advantage to maintain down the H2O tabular arraies and stretch the irrigation supplies.
Another facet associated with injudicious irrigation is leaching of the nomadic foods like nitrate below the root zone of harvests. which decreases the food usage efficiency by harvests. In order to minimise this loss through leaching. it becomes necessary to modulate irrigation and fertiliser applications.
Vii. Cultural Practices to Increase Water Use Efficiency in India
Water has become a cherished trade good in modern agribusiness. Therefore. acceptance of certain patterns is greatly good in wise harnessing of available H2O resources. These cultural patterns are:
1. Cultivated land
Cultivated land operations have a great bearing on irrigational demands of the harvests through their consequence on sub-surface H2O storage and use by harvests. Cultivated land increases infiltration rate. reduces vaporization and enhances incursion of roots into deeper beds. With an increased infiltration. higher H2O storage in the root zone of dirt becomes possible. Greater handiness of dirt lessenings excessively need of auxiliary irrigation.
It is a good known fact that direct vaporization from dirt is an unproductive H2O loss. Cultivated land for seed bed readying opens up dirt and increases vaporization from the tilled bed. but at the same clip. it besides breaks the continuity of upward flow of H2O ( capillary H2O ) from the moist beds at a lower place and as such. reduces H2O loss through vaporization.
Puddling ( a cultivated land pattern. particularly utile for paddy cultivation ) and compression of dirt with suited implements is a utile step to cut down infiltration loss in rough-textured dirts.
2. Land rating
It is an indispensable procedure for conveying approximately unvarying distribution of irrigation H2O ( particularly in surface irrigation ) on undulating and inclining lands. It minimizes the danger of deluging of low lying countries and under-irrigation of raised locations.
3. Fertilizer usage
Recent surveies have proved that fertilisation of harvests enhances I H2O usage efficiency. Besides. fertilisation promotes deeper and more profuse root system which extracts more H2O stored in deeper beds of dirt. Care should be taken non to utilize high doses of fertilisers where H2O supplies are limited.
4. Croping forms
Much attending has non been paid towards the development of appropriate cropping forms which can accommodate the irrigation supplies available at the farm. The usual inclination is to fit irrigation demands to harvests on considerations other than handiness of H2O. The function of harvest planning in regard of efficient usage of H2O has non been good recognized. Such planning is of import because:
a. harvests differ marked by in timings and sums of their irrigation demand ; b. they exhibit a broad scope of photosynthetic efficiency for similar H2O demands ; c. they exhibit differential sensitiveness to H2O emphasis imposed at assorted growing phases.
The harvests that develop their screens quickly. license more efficient usage of H2O by cut downing direct vaporization. Crops with deeper and more profuse root system utilize greater sum of profile-stored H2O and can stand drought better-than the shoal rooted harvests. In some harvests. better tolerance of H2O shortages arises from higher physiological version.
Mulching is the pattern of distributing an immaterial stuff on surface of dirt to increase H2O keeping. look into vaporization. cut down dirt eroding. better edaphic environment and suppress weeds. Assorted types of mulches. viz. paper polyethylene movie. harvest residues. crude oil merchandises. etc. have been used to recognize these aims. But unavailability and high costs of most of these stuffs discourage their big graduated table usage as mulch. In those parts where paddy straw and wheat straw are available in plentifulness. they can be used for mulching.
Straw mulching in harvests. seeded during hot and dry summer has been found to increase harvest outputs and conserve irrigation H2O and fertiliser usage. Therefore. it can be an of import practical assistance in bettering H2O usage efficiency of harvests.
6. Weed control
As weed compete with the harvests for visible radiation. H2O and foods. their development along with the harvest growing enhances rate of soil- H2O depletion. Further. weeds obstruct the motions of H2O in the irrigation channels and Fieldss and therefore advance infiltration loss. These weed-induced effects necessitate more frequent lacrimation. The inauspicious consequence of weed on dirt H2O usage is more marked during early phases of growing when the harvest screen is thin and weeds significantly contribute to canopy and. hence. evapo transpiration loss is high. Therefore. an efficient weed control in the irrigation channels every bit good as in fallow and cropped Fieldss through mechanical operations and weedicides is indispensable to conserve farm irrigation supplies and to increase H2O utilization efficiency for harvest production.
7. Irrigation scheduling
In irrigated countries. optimal irrigation scheduling to crops constitutes a major cultural pattern because it is one of the most of import factors regulating the outputs of harvests. Besides. irrigation programming has profound influence non merely on the efficient direction of an single farmer’s irrigation supplies. but besides on wise planning in relation to canal. bid development and optimum allotment of H2O resources among harvests and parts. A husbandman can easy follow an optimal irrigation agenda provided it is simple and economical.