This document provides an overview of irrigation, including definitions, objectives, necessity, types, and importance. It defines irrigation as supplying water to land through artificial means for crop cultivation. The basic objective is to supplement natural water supply to obtain optimal crop yields. Different types of irrigation systems are described, including flow, lift, flood, sprinkler irrigation. Maintaining soil fertility through practices like crop rotation and addition of manures/fertilizers is also discussed. The document outlines factors that impact the quality of irrigation water such as silt and salt content.

1. IRRIGATION
PRESENTATION BY
K.SAI VIHARI
CIVIL-3A

2. WHAT IS IRRIGATION ?

3. IRRIGATION
 IRRIGATION MAY BE DEFINED AS THE PROCESS OF SUPPLYING WATER TO LAND BY
ARTIFICIAL MEANS FOR THE PURPOSE OF CULTIVATION. ORDINARILY WATER IS
SUPPLIED TO LAND BY NATURE THROUGH RAIN BUT GENERALLY IT IS NOT
ENOUGH FOR THE PROPER GROWTH OF PLANTS.
 BASIC OBJECTIVE OF IRRIGATION IS TO SUPPLEMENT THE NATURAL SUPPLY OF
WATER TO LAND SO AS TO OBTAIN AN OPTIMUM YIELD FROM THE CROP GROWN
ON THE LAND.
 IRRIGATION WATER SHOULD BE SUPPLIED AS SOON AS THE MOISTURE FALLS UP
TO THE OPTIMUM LEVEL. THE QUANTITY OF WATER THAT PRODUCES THE
MAXIMUM YIELD OF THE CROPS IS TERMED AS OPTIMUM WATER LEVEL. MORE OR
LESS THAN THE OPTIMUM LEVEL RESULTS THE REDUCTION OF THE YIELD.

4. Fig: Yield Vs. water depth relationship

5. NECESSITY OF IRRIGATION
 Water is necessary for plant growth and maturity. Irrigation, the artificial means of supplying
water, becomes important for plant growth in the following cases:-
 If rainfall is less than the demand of plants, irrigation is necessary to fulfill the water
requirement of plants.
 The difference in water holding capacity of the soil plays important role in the Necessity of
Irrigation supply. For example, sandy soil requires frequent irrigation than clay soil.
 If rainfall is sufficient but spatial distribution is not as per requirement, irrigation becomes
necessary.

6.  If rainfall is sufficient, spatial distribution is also good but temporal distribution is not
as per requirement, irrigation water is necessary for plants.
 An advanced scientific development like High Yielding Varieties Seeds (HYV) demands
irrigation. Actually, irrigation is the most important input for HYV.
 Factors which necessitate irrigation are as indicated below:-
1)Inadequate rainfall.
2)Uneven Distribution of Rainfall.
3)Growing a Number of Crops during a Year.
4)Growing Superior Crops.

7. IMPORTANCE OF IRRIGATION
 AGRICULTURE IS OFTEN GREATLY HAMPERED DUE TO IRREGULAR, INSUFFICIENT OR
UNCERTAIN RAIN. PROPER IRRIGATION SYSTEMS CAN SECURE UNINTERRUPTED
AGRICULTURE.
 THE PRODUCTIVITY OF IRRIGATED LAND IS MORE THAN THE UN-IRRIGATED LAND.
CROP YIELDS EVERYWHERE IN THE DEVELOPING WORLD ARE CONSISTENTLY HIGHER
IN IRRIGATED AREAS THAN IN RAINFED AREAS.
 SEEDS CANNOT GROW IN DRY SOIL AS MOISTURE IS NECESSARY FOR THE
GERMINATION OF SEEDS. WITH THE HELP OF IRRIGATION SUPPLY, THE REQUIRED
MOISTURE CONTENT OF SOIL FOR THE GROWTH OF SEED CAN BE ENSURED.
 MULTIPLE CROPPING IN A YEAR IS POSSIBLE THROUGH IRRIGATION. THIS WILL
ENHANCE PRODUCTION & PRODUCTIVITY. IN MANY AREAS OF INDIA, TWO OR THREE
CROPS IN A YEAR ARE CULTIVATED WITH IRRIGATION FACILITIES.

8.  Through the irrigation, it is possible to supply the required amount of hydrogen & oxygen,
which is important for the proper development of plant root.
 A plant can absorb mineral nutrients from the irrigated soil. Thus irrigation is essential for the
general growth of the plant.
 Bringing more land under cultivation is possible through irrigation.
 Insufficient rain may also cause drought & famines. Irrigation can play a protective role
during the period of drought & famines.
 Irrigation contributes to the economic growth and poverty reduction. As income and
employment are closely related to output and irrigation increases production, substantial
increase in income is achieved in the countryside.

10. ADVANTAGES OF IRRIGATION
o GENERAL DEVELOPMENT OF THE COUNTRY, PROSPERITY OF THE PEOPLE AND WEALTH OF THE NATION.
o PROTECTION AGAINST FAMINE AND ATTAINMENT OF SELF SUFFICIENCY IN FOOD.
o IMPROVEMENT IN YIELD OF CROPS AND APPRECIATION IN LAND VALUE.
o GENERATION OF HYDROELECTRIC POWER: CANAL FALL MAY SOMETIMES BE UTILIZED FOR GENERATION OF
POWER.
o INLAND NAVIGATION: IT IS POSSIBLE THAT SOME LARGE IRRIGATION CANALS MAY BE DEVELOPED FOR
NAVIGATION PURPOSES.
o DOMESTIC WATER SUPPLY: AT MANY PLACES IRRIGATION CANALS ARE THE ONLY SOURCE OF SUPPLY FOR
DOMESTIC WATER.
o IMPROVEMENT OF COMMUNICATION: ROADS PROVIDED ALONG-SIDE THE IMPORTANT CANALS PRIMARILY
FOR INSPECTIONS, ARE UTILIZED FOR GENERAL COMMUNICATION ALSO.
o PLANTATION: TREE ARE PLANTED ALONG CANAL BANKS, FIELD BOUNDARIES, ETC INCREASING TIMBER,
FUEL AND FRUIT SUPPLIES.
o IMPROVEMENT IN THE GROUND WATER STORAGE: CANAL AND IRRIGATION WATER SEEP THROUGH THE
SOIL AND RAISES THE WATER TABLE. THIS IS DESIRABLE IN ARID AND SEMIARID ZONES.

11. ILL EFFECTS OF IRRIGATION
WATER LOGGING.
BREEDING PLACES FOR MOSQUITOES.
UNHEALTHY CLIMATE.
 POLLUTION OF RIVER FLOWS AND GROUNDWATER.

12. WHAT ARE TYPES OF
IRRIGATION?

14. FLOW IRRIGATION SYSTEM
• FLOW IRRIGATION SYSTEM IS THAT SYSTEM OF IRRIGATION IN WHICH THE
IRRIGATION WATER IS AVAILABLE AT SUCH A LEVEL IT IS CONVEYED TO THE
LAND TO BE IRRIGATED BY GRAVITY FLOW.
• THE IRRIGATION PRACTISED IN THIS SYSTEM IS KNOWN AS FLOW IRRIGATION.
IT IS CLASSIFIED INTO TWO TYPES:-
a) DIRECT IRRIGATION SYSTEM.
b) RESERVOIR OR TANK OR STORAGE IRRIGATION SYSTEM.

15. GRAVITY FLOW
IRRIGATION

16. LIFT IRRIGATION
 IN THIS SYSTEM OF IRRIGATION IN WHICH THE IRRIGATION WATER
IS LOWER LEVEL THAN THAT OF LAND IS TO BE IRRIGATED.
 THE WATER CAN BE LIFTED UP BY PUMPS.
 THEN WATER IS CONVEYED BY GRAVITY FLOW METHOD.
 THIS IS KNOW AS ‘LIFT IRRIGATION’
 WELL IS AN EXAMPLE OF LIFT IRRIGATION SYSTEM.

17. FLOOD
IRRIGATION

18. FLOODING METHODS
o UNCONTROLLED OR WILD
FLOODING:-
IN THIS METHOD OF IRRIGATION
WATER IS APPLIED BY SPREADING IT
OVER THE LAND TO BE IRRIGATED
WITHOUT ANY PRIOR PREPARATION
OF LAND
IT IS SUITABLE FOR SMOOTH AND
FLAT LAND
o CONTROLLED FLOODING:-
IN THIS METHOD OF IRRIGATION
WATER IS APPLIED BY SPREADING IT
OVER THE LAND TO BE IRRIGATED
WITH PROPER CONTROL BEING
ENFORCED ON THE FLOW OF
WATER
PREPARATION OF LAND IS
ESSENTIAL

19. FLOODING FROM FIELDS
• IN THIS METHOD THE LAND TO BE IRRIGATED IS DIVIDED INTO SMALL STRIPS BY
A SERIES OF FIELD CHANNELS WHICH ARE SUPPLY CHANNELS.
• THE CHANNELS MAY BE ALIGNED ALONG THE CONTOUR LINES; OR AT RIGHT
ANGLES TO THE CONTOUR LINES; OR AT RIGHT ANGLES TO THE SIDES OF THE
LAND.
• WHEN THE CHANNELS ARE ARRANGED ACCORDING TO RIGHT ANGLES TO THE
CONTOUR LINES THEN BOTH SIDES OF LAND CAN BE IRRIGATED.
• THIS METHOD IS USED ON RELATIVELY STEEP SLOPES AS WELL AS ON FLAT
LANDS.

27. RING BASIN METHOD
• IT IS SPECIAL FORM OF CHECK BASIN METHOD OF IRRIGATION
• IT IS USED FOR THE IRRIGATION OF ORCHARDS
• IN THIS METHOD EACH TREE A SEPARATE BASIN IS MADE WHICH IS
USUALLY CIRCULAR IN SHAPE
• HENCE IT IS KNOWN AS RING BASIN
• MOST CASES EACH BASIN IS PROVIDED WITH SEPARATE FIELD CHANNEL
• IN SOME CASES ALL BASINS ARE INTERCONNECTED SO THAT SUPPLY
CHANNEL WATER IS CONVEYED TO ONE OF THE BASINS AND BY
FLOWING FROM ONE BASIN INTO ANOTHER THE WATER IS SUPPLIED TO
ALL THE BASINS

30. FURROW METHOD
o IN THIS METHOD WATER IS APPLIED TO THE LAND TO BE IRRIGATED
BY A SERIES OF LONG, NARROW FIELD CHANNELS CALLED
FURROWS
o THIS FURROWS ARE DUG IN THE LAND AT REGULAR INTERVALS
o THE WATER FLOWING IN THE FURROWS INFILTRATES INTO SOIL AND
SPREADS LATERALLY TO IRRIGATE THE LAND BETWEEN THE
FURROWS
o THE FURROW METHOD OF IRRIGATION IS COMMONLY USED FOR
ROW CROPS SUCH AS MAIZE, COTTON, POTATOES, SUGAR CANE,
SUGAR BEAT, GROUNDNUT, ETC.

33. SPRINKLER IRRIGATION METHOD
 IN THE SPRINKLER IRRIGATION METHOD THE IRRIGATION WATER IS APPLIED TO
THE LAND IN THE FORM OF SPRAY OR LIKE RAIN.
 SPRINKLER IRRIGATION IS ALSO KNOWN AS OVERHEAD IRRIGATION.
 THE COMPONENTS OF A SPRINKLER IRRIGATION SYSTEM ARE MAINS, SUB MAINS,
LATERALS, RISER PIPES, SPRINKLERS, AND A PUMPING UNIT.
 THE PUMP LIFTS WATER FROM THE SOURCE AND SUPPLIES IT THROUGH THE
PIPES TO THE SPRINKLERS.
 THREE TYPES OF SPRINKLERS ARE GENERALLY USED.
1.FIXED NOZZLE PIPE.
2.PERFORATED PIPE.
3.ROTATING PIPE.

35. This Photo by Unknown Author is licensed under CC BY-SA-NCThis Photo by Unknown Author is licensed under CC BY-SA

37. IMPROVING SOIL FERTILITY
 FOR OPTIMUM YIELD OF A CROP IT IS ESSENTIAL THAT THE SOIL ON WHICH IT IS
GROWN IS FERTILE.
 A SOIL IS SAID TO BE FERTILE IF IT HAS AMPLE STORAGE OF THE NUTRIENTS
REQUIRED BY THE CROP FOR ITS GROWTH.
 USING OF LAND AGAIN AND AGAIN FOR GROWING CROPS THEN SINCE NUTRIENTS
ARE CONSUMED THE SOIL BECOMES DEFICIENT IN THE NUTRIENTS, AS A RESULT
CROP YIELD DECREASES.
 VARIOUS METHODS ADOPTED TO MAINTAIN FERTILITY OF SOIL:-
1. BY KEEPING THE LAND FALLOW.
2. ADDITION OF MANURE AND FERTILIZERS.
3. CROP ROTATION.
4. MIXED OR INTER CROPPING.

38. BY KEEPING THE LAND FALLOW:- IF THE LAND IS KEPT FALLOW I.E., IT
IS LEFT UNCULTIVATED FOR ONE OR MORE CROP SEASONS THEN THE
SOIL IS ALLOWED TO RECOUP IN RESPECT OF THE NUTRIENTS WHICH
ARE DEFICIENT AND THUS REGAIN ITS FERTILITY.
ADDITION OF MANURE AND FERTILIZERS:- IF THE SOIL IS DEFICIENT IN
SOME NUTRIENTS THEN BY ADDING MANURE AS WELL AS FERTILIZERS
THE DEFICIENCY IS REMOVED AND THE FERTILITY OF THE SOIL IS
IMPROVED.
CROP ROTATION:- CROP ROTATION MEANS CHANGING THE CROPS TO
BE GROWN EVERY YEAR IN THE SAME FIELD.IN OTHER WORDS IT IS A
PROCESS OF GROWING DIFFERENT CROPS IN ROTATION IN THE SAME
FIELD.

39.  IF THE SAME CROP IS GROWN EVERY YEAR IN ANY FIELD THEN SINCE THE SAME
TYPE OF NUTRIENTS ARE CONSUMED THE SOIL BECOMES DEFICIENT IN THESE
NUTRIENTS. ON THE OTHER HAND IF DIFFERENT CROPS ARE GROWN IN THE
SAME FIELD THEN SINCE DIFFERENT CROPS REQUIRE DIFFERENT NUTRIENTS AND
IN DIFFERENT PROPORTIONS A BALANCED UTILIZATION OF THE NUTRIENTS
RESULTS AND SOIL DOES NOT DEFICIENT IN PARTICULAR TYPE OF NUTRIENT.
 EXAMPLES ARE GIVEN BELOW:-
A.WHEAT-GREAT-MILLET.
B. RICE-GRAM.
C.COTTON-WHEAT-GRAM.

40. MIXED OR INTER CROPPING:-MIXED OR INTER CROPPING IS DEFINED
AS THE GROWING OF TWO OR MORE CROPS TOGETHER IN THE
SAME FIELD DURING THE SAME CROP SEASON. FOR EXAMPLE WHEAT
AND MUSTARD MAY BE GROWN SIMULTANEOUSLY IN THE SAME
FIELD. IN MIXED OR INTER CROPPING THE OPTIMUM UTILIZATION
OF THE NUTRIENTS AVAILABLE IN THE SOIL IS MADE.

41. QUALITY OF IRRIGATION WATER
 GENERALLY IRRIGATION WATER IS NOT INTENDED TO PROVIDE ANY NUTRIENT,
TRACE ELEMENT OR ANY OTHER ELEMENT NEEDED FOR THE GROWTH OF
PLANTS.
 SOME OF THE INGREDIENTS PRESENT IN IRRIGATION WATER MAY BE INJURIOUS
TO THE PLANT GROWTH, WHICH WOULD RENDER THE WATER UNSUITABLE FOR
IRRIGATION.
 AS SUCH THE QUALITY OF IRRIGATION WATER DEPENDS PRIMARILY ON ITS SILT
CONTENT AND SOIL CONSTITUENTS.
 FACTORS THAT EFFECT THE QUALITY OF IRRIGATION WATER:-
1.EFFECT OF SILT.
2.EFFECT OF SALTS.

42. • EFFECT OF SILT. THE EFFECT OF SILT ON THE QUALITY OF IRRIGATION WATER
DEPENDS ON THE NATURE OF THE SILT MATERIAL AND THE CHARACTERISTICS
OF THE SOIL RECEIVING THE WATER. THUS IF THE SILT CONTAINS A LARGER
CONTENT OF PLANT NUTRIENTS COMES FROM THE FERTILE LANDS THEN IT IS
QUITE BENEFICIAL, PARTICULARLY FOR VIRGIN SOILS OF THE AGRICULTURAL
LAND WHICH HAS A LOW CONTENT OF PLANT NUTRIENTS AND A VERY LOW
WATER HOLDING CAPACITY.
• EFFECTS OF SALTS. SALTS OF HEAVY ELEMENTS SUCH AS LEAD, SELENIUM,
ARSENIC ., ARE INJURIOUS TO THE PLANT GROWTH EVEN IF THEY ARE PRESENT
IN LOW CONCENTRATIONS. HOWEVER, UNDER NORMAL CONDITIONS THE
SOLUBILITIES OF THESE SALTS ARE QUITE LOW AND HENCE THE
CONCENTRATIONS OF THESE SALTS ARE USUALLY LESS THAN THOSE WHICH
MAY BE HARMFUL FOR THE PLANTS.