hort-102 irrigation of hort crops

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IRRIGATION OF IRRIGATION OF HORTICULTURAL CROPSHORTICULTURAL CROPS

By:By:Dr. Ahmad Dr. Ahmad SattarSattar KhanKhan

Hort-102 IHS, Univ. of Agri. Fsd. (Dr. Ahmad Sattar Khan)

Out LineOut Line

Importance of water for horticultural plants

Factor affecting irrigation requirements

Irrigation why, how much and when?

Water quality

Critical periods

Selection of irrigation system for horticulturalcrops


WHY WATER IS IMPORTANT?WHY WATER IS IMPORTANT?

An essential environmental factor controlled bydrainage, storage, and irrigation.

An optimum supply of water is essential formaximum development of roots.

Well developed roots in turn absorb optimalquantities of water and nutrients, producinghealthy top growth and higher yields.

Excess of water causes unhealthy roots due topoor soil aeration.

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WATER IN PLANTS WATER IN PLANTS –– A NECESSITYA NECESSITY AA normalnormal constituent ofof allall plantplant tissuestissues.. RateRate ofof formationformation ofof carbohydrates andand organicorganic

nitrogenousnitrogenous compoundscompounds isis directlydirectlyproportionateproportionate toto thethe amountamount ofof waterwater inin plantplanttissuestissues..

WaterWater mustmust bebe presentpresent inin thethe soilsoil toto encourageencouragefixationfixation andand asas aa medium ofof transport forfornutrientnutrient mineralsminerals..

WaterWater hashas aa moderatingmoderating effecteffect onon temperature.. KeepsKeeps thethe plantplant cellcell turgid whichwhich isis essentialessential forfor

normalnormal growthgrowth andand cellcell divisiondivision.. ImportantImportant forfor enzyme activityactivity.. EnzymeEnzyme activityactivity isis

affectedaffected byby deficiencydeficiency ofof waterwater..


Susceptibility ofSusceptibility of Horticultural plants to Horticultural plants to environmental harshnessenvironmental harshness

Horticultural plants are very sensitive to theirenvironment. They react adversely to excessiveheat, frost, dry soil, wet soil, low soil oxygen and airpollution.

Poor irrigation results in areas of soil dryness andexcessively wet soil is a strongly contributing causeof low soil oxygen.

Damage from excessive heat has been observed tobe greater in poorly irrigated soils than in soil whichhas been well irrigated.


Kind of plant Plant size Age of plant Climatic conditions Soil characteristics (water holding capacity,

soil texture, depth of irrigation) Intercultural practices Presence or absence of wind breaks

FACTORS AFFECTING IRRIGATION REQUIREMENT OF PLANTS



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IRRIGATION IRRIGATION -- WHY, WHEN & HOW MUCH WHY, WHEN & HOW MUCH

The aim of irrigation should be to wet the soil to aneven depth around the root zone.

Water which penetrates below the root zone cannotbe used by the root and is wasted.

The depth of rooting can markedly affect how long acrop can thrive without the addition of water.

Lettuce, strawberry and radish plants are shallowrooted and deplete the zone of available moisturemore rapidly than do deep rooted crops such astomato and tree crops.


FrequentFrequent butbut lightlight irrigationirrigation isis neededneeded forfor shallowshallowrootedrooted cropscrops andand heavyheavy butbut lessless frequentfrequent irrigationirrigation forfordeepdeep rootedrooted plantsplants..

IrrigationIrrigation frequencyfrequency alsoalso dependsdepends onon thethe soilsoil typetype..

FineFine texturedtextured soilssoils holdhold moisturemoisture longerlonger thanthancoarsecoarse texturedtextured soilssoils..

DeeperDeeper soilssoils holdhold moremore waterwater thanthan shallowshallow onesones..

OrganicOrganic mattermatter increasesincreases thethe waterwater holdingholdingcapacitycapacity ofof lightlight soilssoils andand improvesimproves aerationaeration ofofheavyheavy soilssoils..

IRRIGATION IRRIGATION ––WHY, WHEN & HOW MUCH (Cont…)WHY, WHEN & HOW MUCH (Cont…)


Irrigation needs vary from spp. to spp. and fromregion to region.

For example with citrus fruits 30 hectare-cm/hairrigation is needed near the coast and thisrequirement increases to 90 or more hectare-cm/ha in the interior.

Water should be given to the plants when most of theroot zone is nearly dry.

In summer orchards should be irrigated fortnightlyand in winter irrigation is done every monthdepending upon precipitation.

IRRIGATION IRRIGATION –– WHY, WHEN & HOW MUCH (Cont…)WHY, WHEN & HOW MUCH (Cont…)



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WATER QUALITYWATER QUALITY

MostMost horticulturalhorticultural plantsplants areare veryvery sensitive toto thethepresencepresence ofof salts inin irrigationirrigation waterwater asas wellwell asas inin thethesoilsoil..

ItIt isis therefore,therefore, importantimportant toto knowknow thethe qualityquality ofof waterwaterusedused forfor irrigationirrigation variousvarious horticulturalhorticultural cropscrops..

TheseThese cropscrops varyvary inin theirtheir tolerancetolerance ofof variousvarious salts,,soso aa waterwater analysisanalysis isis advisableadvisable..

TheThe waterwater shouldshould notnot containcontain amountsamounts ofof dissolveddissolvedsaltssalts excessiveexcessive forfor thethe cropcrop toto bebe raisedraised..


WATER QUALITYWATER QUALITY Irrigation water may comes from canals, wells, tube

wells, ponds or lakes, which may contain salts invariable quantities.

Water containing salts at 2000 mgL-1 or abovecauses injury to most horticultural plants, and evenlower concentrations may prove dangerous unlessthey are diluted or drained away by rain or liberalirrigation.

Chlorides and sodium salts are most harmful.

Chlorides are said to be more injurious thansulphates, while carbonates are considered to be themost injurious of all salts.


WATER QUALITYWATER QUALITY

If there is any sign of salt accumulation in the soil,an irrigation of at least 15 hectares-cm isrecommended.

When the natural salt content of the soil orirrigation water is high, water should be applied inexcess of the needs of plants in order to reduce theconcentration of soluble salts in the root zone.



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CRITICAL PERIOD ????CRITICAL PERIOD ????

There are critical periods for watersupply in the life span of every plant.

During these critical periods, irrigation isessential.

If water is not applied during this periodyield will be badly affected.


CRITICAL PERIODS FOR HORT. CROPSCRITICAL PERIODS FOR HORT. CROPS

CRITICAL PERIODS VEGETABLES

Germination All species, particularly vegetables All species, particularly vegetables & annual flowers& annual flowers

Pollination BeansBeans

Pod Enlargement Peas & beansPeas & beans

Head Development Cauliflower, cabbage, broccoliCauliflower, cabbage, broccoli

Root, Bulb & Tuber Enlargement

Carrots, radishes, turnips, onions, Carrots, radishes, turnips, onions, potatoespotatoes

Flowering, Fruit & Seed Development

Cucumbers, Squashes, peasCucumbers, Squashes, peas

Fruit Set & Development MelonsMelons

Flowering to Harvesting Eggplant, Peppers, TomatoesEggplant, Peppers, Tomatoes


SELECTION OF IRRIGATION SYSTEMSELECTION OF IRRIGATION SYSTEM

ToTo choosechoose anan irrigationirrigation method,method, thethe growergrowermustmust knowknow thethe advantagesadvantages andand disadvantagesdisadvantagesofof thethe variousvarious methodsmethods..

HeHe mustmust knowknow whichwhich methodmethod suitssuits thethe locallocalconditionsconditions bestbest..

Unfortunately,Unfortunately, inin manymany casescases therethere isis nono singlesinglebestbest solutionsolution:: allall methodsmethods havehave theirtheiradvantagesadvantages andand disadvantagesdisadvantages..



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FACTORS AFFECTING FACTORS AFFECTING SUITABILITY OF IRRIGATION SYSTEMSUITABILITY OF IRRIGATION SYSTEM

Suitability of various irrigation methods, e.g., Suitability of various irrigation methods, e.g., surface, sprinkler or drip irrigation, depends mainly surface, sprinkler or drip irrigation, depends mainly on the following factors: on the following factors:

natural conditions (type and slope of soil, wind, (type and slope of soil, wind, water quality)water quality)

type of type of crop (trees or vegetables)(trees or vegetables)

previous experience with irrigationwith irrigation

required required labour inputs (maintenance)inputs (maintenance)

costs and and benefits


IRRIGATION SYSTEMS FOR IRRIGATION SYSTEMS FOR VEGETABLE CROPSVEGETABLE CROPS

WithWith vegetablevegetable crops,crops, appropriateappropriate irrigationirrigationpracticespractices varyvary forfor differentdifferent speciesspecies andand fromfromareaarea toto areaarea,, dependingdepending onon agroagro--climaticclimaticconditionsconditions.. VegetableVegetable cropscrops areare irrigatedirrigatedthroughthrough::

SurfaceSurface irrigationirrigation systemsystem

SubsurfaceSubsurface irrigationirrigation systemsystem

SpraySpray irrigationirrigation systemsystem


ApplicationApplication ofof waterwater directlydirectly toto thethe soilsoil surfacesurface..

ThisThis systemsystem isis usedused onon deep,deep, compact,compact, andanduniformlyuniformly texturedtextured soilssoils withwith aa gentlegentle slopeslope..

SurfaceSurface irrigationirrigation isis givengiven toto vegetablevegetable cropscropsthroughthrough thethe borderborder andand furrowfurrow systemsystem..

InIn borderborder systemsystem,, afterafter landland leveling,leveling, bordersborders 1515--2525 cmcmhighhigh areare mademade aroundaround thethe field,field, whichwhich maymay bebe divideddividedintointo subsub--blocksblocks forfor separateseparate irrigationirrigation..

InIn furrowfurrow systemsystem,, landland isis thoroughlythoroughly levelledlevelled andand 1515--2020cmcm deepdeep furrowsfurrows areare mademade betweenbetween thethe rows,rows, thisthismethodmethod isis usedused withwith vegetablesvegetables growngrown inin rowsrows inin thethearidarid andand semisemi--aridarid regionsregions ofof pakistanpakistan..

SURFACE IRRIGATIONSURFACE IRRIGATION



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BORDER IRRIGATION SYSTEMBORDER IRRIGATION SYSTEM


FURROW IRRIGATION SYSTEM


SUB SURFACE IRRIGATION

Water is applied under the soil surface in the root zone of the plants through emitters.

It is continuously available, loss of water is minimized, there is no loss of water from the soil surface, and more soil can be utilized for vegetable raising.

On the other hand, it is very costly and difficult to install and operate.



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SUBSUB--SURFACE IRRIGATIONSURFACE IRRIGATION


SPRAY IRRIGATIONSPRAY IRRIGATION

It is an application of water to crops in the form It is an application of water to crops in the form of a spray similar to of a spray similar to gentle rain..

Irrigation by this method can be used for Irrigation by this method can be used for vegetables growing on all types vegetables growing on all types of soils, and on both leveled and rolling land..


MERITS & DEMERITS OF SPRAY MERITS & DEMERITS OF SPRAY IRRIGATIONIRRIGATION

UniformUniform distributiondistribution ofof waterwater onon allall typestypes ofof soilsoilwithwith minimumminimum lossloss ofof waterwater andand nutrientsnutrientsthroughthrough leaching,leaching, nono soilsoil erosion,erosion, andand fullfullutilizationutilization ofof landland..

HoweverHowever itsits initialinitial andand operating costs areareveryvery highhigh..

ItIt maymay alsoalso notnot workwork inin areasareas withwith continuouscontinuousstrong winds,, andand maymay causecause excessiveexcessive losslossofof waterwater throughthrough evaporationevaporation..



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SPRAY IRRIGATION SYSTEM


METHODS OF IRRIGATION FOR METHODS OF IRRIGATION FOR FRUIT CROPSFRUIT CROPS

Channel systemChannel system Channel basin systemChannel basin system Modified basin systemModified basin system Flooding Flooding Furrow irrigation systemFurrow irrigation system Sprinkler irrigation systemSprinkler irrigation system Drip or trickle irrigation systemDrip or trickle irrigation system AlternateAlternate––middle irrigation systemmiddle irrigation system


CHANNEL SYSTEMCHANNEL SYSTEM

InIn thisthis systemsystem treestrees areare connectedconnected byby channelchannelandand waterwater isis givengiven toto thethe plantsplants throughthrough themthem..

ThisThis isis aa simple andand easy methodmethod ofofirrigationirrigation whichwhich requirerequire little labour andandlittlelittle technicaltechnical knowknow howhow..

ItIt causescauses muchmuch water loss andand thethepassagepassage ofof infection fromfrom oneone treetree totoanotheranother..



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CHANNELCHANNEL--BASIN SYSTEMBASIN SYSTEM

TreesTrees areare connectedconnected withwith channelschannels butbut aroundaround eacheachtreetree aa basinbasin isis mademade..

ThisThis isis aa simple andand easy methodmethod ofof irrigationirrigation whichwhichrequirerequire littlelittle labourlabour andand littlelittle technicaltechnical knowknow howhow..

ItIt causescauses muchmuch water loss andand thethe passagepassage ofofinfectioninfection fromfrom oneone treetree toto anotheranother..

MoreMore ofof thethe rootroot zonezone isis wettedwetted andand requirerequire moremorelabour toto makemake thethe channelschannels andand basinbasin andand keepkeepthemthem cleanclean..




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MODIFIEDMODIFIED--BASIN SYSTEMBASIN SYSTEM

InIn thisthis systemsystem aa waterwater channelchannel isis mademadebetweenbetween thethe treetree rowsrows..

BasinsBasins areare mademade aroundaround thethe treetree trunkstrunks andandthenthen individuallyindividually connectedconnected withwith thethe centralcentralwaterwater channelchannel..

LayingLaying outout thisthis systemsystem isis difficult andandexpensiveexpensive andand intercropping isis impossiblebutbut waterwater lossloss isis reducedreduced..

Hort-102 IHS, Univ. of Agri. Fsd. (Dr. Ahmad Sattar Khan)MODIFIED BASIN SYSTEM


FLOODINGFLOODING

FloodingFlooding likelike thatthat donedone forfor fieldfield cropscrops isis alsoalsothethe generalgeneral practicepractice forfor irrigatingirrigating orchardsorchardsinin PakistanPakistan..

ItIt isis thethe simplest easiest andand cheapestcheapest,method,method butbut causescauses maximummaximum water lossesleaching ofof nutrientsnutrients andand unevenuneven waterwaterdistributiondistribution inin thethe fieldfield whichwhich maymay resultresult ininwaterwater logginglogging..

ItIt cancan notnot bebe usedused onon unevenuneven oror unleveledunleveledsoilssoils..



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FLOOD IRRIGATION SYSTEMFLOOD IRRIGATION SYSTEM


FURROW IRRIGATIONFURROW IRRIGATION ItIt cancan notnot bebe donedone inin thethe slope ofof thethe landland andand sizesize ofof

waterwater sourcesource areare suchsuch thatthat theythey willwill notnot causecauseerosionerosion..

FurrowsFurrows shouldshould bebe spacedspaced closeclose enoughenough togethertogether sosothatthat thethe wettedwetted areasareas meetmeet andand thethe waterwater isis keptkept ininfurrowsfurrows untiluntil itit hashas penetratedpenetrated toto thethe desireddesired depthdepth..

InIn thisthis methodmethod waterwater loss isis minimized andand waterwaterlogginglogging doesdoes notnot occuroccur..

Less labour isis neededneeded toto setupsetup andand maintainmaintain thethefurrowsfurrows..

ItIt causescauses uneven distributiondistribution ofof water,water, makingmaking lesslesswaterwater availableavailable toto thethe rootroot zonezone andand required morefrequent irrigationirrigation..


FURROW IRRIGATION SYSTEMFURROW IRRIGATION SYSTEM



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Stream size is too small to wet the ridgeStream size is too small to wet the ridge


SPRINKLER IRRIGATIONSPRINKLER IRRIGATION

Sprinkler can be used under a variety of Sprinkler can be used under a variety of conditions, and can be adapted to rolling or conditions, and can be adapted to rolling or steep lands and to soil of steep lands and to soil of non uniformtopography. topography.

AdvantageAdvantage isis thatthat theythey needneed nono land leveling

DisadvantageDisadvantage ofof sprinklerssprinklers areare thatthat theythey havehavehigh capital investmentinvestment andand maintenancemaintenancecosts,costs, andand theythey limitlimit thethe amountamount ofof waterwater thatthatcancan bebe appliedapplied atat oneone settingsetting ofof thethe pipelinespipelines..


TYPES OF SPRINKLERSTYPES OF SPRINKLERS

OverheadOverhead systemsystem UnderUnder--treetree sprinklersprinkler PortablePortable sprinklersprinkler PerforatedPerforated sprinklersprinkler



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Overhead sprinkler irrigation system


Under tree sprinkler irrigation system


PORTABLE SPRINKLER PORTABLE SPRINKLER IRRIGATION SYSTEMIRRIGATION SYSTEM



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PORTABLE PERFORATED PIPESPORTABLE PERFORATED PIPES


DRIP OR TRICKLE DRIP OR TRICKLE IRRIGATION SYSTEMIRRIGATION SYSTEM

DripDrip oror trickletrickle irrigationirrigation onlyonly wetswets aa specificspecificareaarea surroundingsurrounding thethe plantsplants..

TheThe raterate ofof applicationapplication isis soso slow thatthat littlelittle orornono flowflow ofof waterwater occuroccur onon thethe surfacesurface..

ThisThis systemsystem dischargesdischarges thethe waterwater onon toto thethegroundground throughthrough oneone oror moremore emitters adjacentadjacenttoto eacheach treetree

ItIt maymay eithereither bebe buriedburied slightlyslightly betweenbetween treestreesoror lielie onon thethe surfacesurface inin thisthis systemsystem

Frequent irrigation isis neededneeded..


Advantages of drip irrigation systemAdvantages of drip irrigation system

waterwater saving RestrictionRestriction ofof weed growthgrowth BetterBetter supplysupply ofof chemicals andand fertilizers .. PerformancePerformance willwill notnot bebe affectedaffected byby winds oror

duringduring dayday andand nightnight ..

DisadvantagesDisadvantages

Costly to installto install Continuity of flow of water through emitter is of flow of water through emitter is

unreliable Salt Salt accumulate around the root zone of the plantaround the root zone of the plant



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DRIP IRRIGATION SYSTEMDRIP IRRIGATION SYSTEM


ALTERNATE MIDDLE IRRIGATIONALTERNATE MIDDLE IRRIGATION In this system, every other space between rows is

watered with under tree sprinklers leaving half thebetween row spaces un watered.

At the next irrigation the previously un wateredmiddles are irrigated.

Thus one side of every tree in the orchard receiveswater at each irrigation. It is helpful in overcomingthe effects of water shortage. This method is based on fact that water absorbed

by an portion of the roots system is freelytranslocated to any part of branches and leaves ofthe trees.




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