drip irrigation

Drip irrigation designing

Presented By:-Bhupesh Katariya

W.R.M 3rd Sem(120280712008)

Guided by:-Prof. A. T. MotiyaniL. D. College of Engg.

ContentsIntroductionAdvantagesDisadvantagesComparison with other irrigation systemComponents of drip irrigation systemDesign of drip irrigation systemDesign procedureExample of designingBenefits for farmer

IntroductionIrrigation is an artificial application of water

to the soil through various systems of tubes, pumps, and sprays.

Irrigation is normally used in areas where rainfall is inconsistent or dry conditions or drought is expected.

Drip IrrigationDrip irrigation is a micro irrigation method in

which the rate of water application is very low and without any pressure. i.e., drop by drop

Drip irrigation is based on the basic concept of irrigation only the roots zone of crop , rather than the entire land surface on which the crop is grow.

Water flows from the emission points through the soil by capillarity and gravity.

The soil moisture content of the crop root zone is maintain at near optimum level to facilate optimum crop growth and production.

ARRANGEMENT FOR DRIP SYSTEM

Drip irrigation is useful for crop…..Fruit crops :

Banana, Grapes, Citrus, Pomegranate, Papaya, Pineapple, Watermelon, Sweet lime, Mango, Kinnow, Mosambi.

Vegetable crops : Cabbage, Cauliflower, Okra, Tomato, Potato, Onion,

Chillis, Radish, Brinjal, Bottle grown, French been, Capsicum, Bhindi, Beans, Baby corn, Carrots, Cucumber, Bitter gourd, Bottle gourd, Ashgourd, Gherkins.

Commercial crops : Sugarcane, Cotton, Ground nut, Chickpea.

Advantages of Drip Irrigation Less requirement of irrigation water Water supply at optimum level. Water logging is avoided High yield Over irrigation is avoided Variation in application rate Reduced labour cost Weed control

Increase in net irrigable areaHighly uniform distribution of water i.e.,

Controlled by output of each nozzle No soil erosion

Suitable for any topography Maintenance of high surface temperature Improved disease and pest controlTolerance to windy atmospheric condition

Disadvantages of drip irrigationHigh cost :

drip irrigation systems are expensive because of there requirements of large quantity of piping & filtration equipment to clean the water.

Expense: Initial cost can be more than overhead systems.

Waste:The sun can affect the tubes used for drip irrigation,

shortening their usable life. Longevity is variable.Clogging:

If the water is not properly filtered and the equipment not properly maintained, it can result in clogging.

Drip tape causes extra cleanup costs after harvest. You'll need to plan for drip tape winding, disposal, recycling or reuse.

This method is not suitable for closely planted crops such as wheat

COMPARISONDrip method Flood method

Water savingHigh, between 40 and 100 %

Less. High rates of evaporation, surface run off and percolation

Irrigation efficiency 80 – 90 % 30 - 50 %

Weed problem Almost nil High

Suitable water Even saline water can

be used

Only normal water can

be used

Diseases and pests Relatively less High

Efficiency of fertilizer use

Very high since supply

is regulated

Heavy losses due to

leaching

Drip method Flood method

Water logging Nil High

Water controlCan be regulated easily Not much control

Cost benefit ratio (additional amount in rupees for every rupee invested)

Excluding water savings: 1.3 - 13.3, Including water savings: 2.8 - 30.0

Between 1.8 and 3.9

Capital cost/ha Rs 15,000 to 40, 000

depending ––on crop spacing

Yield increase20 - 100 % higher than flood method

Less compared to drip

Crops: Drip versus Flood irrigation

Components of Drip Irrigation systemPumping setFiltersMainlinesSub-mainLateralsDrippers/emitters

Pumping set:To create a pressure about 2.5 Kg/sq cm to regulate the amount of water to be supplied.

• Filter :To filter the water in Order to remove the suspended impurities from water.

Main lines:It is a Distribution system in drip

irrigation. Rigid PVC and high density polyethylene pipes are used as main pipes to minimized corrosion and clogging.

Pipes of 65 mm diameter and with pressure rating of 4 to 10 kg/sq. cm

Sub Main:It is usually connected to the main

lines through a control valve assembly.

The function of its to distributes water uniformly to a number laterals.

Drippers/emitters:It is fitted to a drip irrigation

lateral and intended to emit water in the form of drops or continuous flow at emitter rates not exceeding 15 liters/hr.

Drippers function as energy dissipated, reducing the inlet pressure head in the lateral, which generally range from 0.3 to 1.5 atmosphere .

Design of Drip irrigation systemData collection

Types of soil Infiltration characteristics of soilTypes of cropConsumptive use of water by cropsWater qualityClimate conditionAvailability of funds Contour map

Design proceduresPrepare on inventory of available resources &

operating conditionsDetermine the water requirement to be met by the

drip systemDetermine the appropriate type of systemDetermine the type and design of emitters Determine the capacity of pumping systemDecide on the economic sizes of the pumping systemDetermine the maximum and minimum operating

pressure and the minimum efficiency requiredDetermine the appropriate filtering systemDetermine the requirement of the fertilization systemPlan field evaluationPrepare drawings, specification, cost ,schedules,

installation, operations ,maintenance.

Emitter SelectionThe efficiency Of Drip irrigation system

depends mainly on the selection of the type of emitter and its design.

Characteristic of emitter that influence the efficiency of irrigation system is Discharge rate

Critical items in emitter selection are the % area wetted(Pw) and the emitter reliability.

The density of emission points required to obtain Pw ≥ 33% .

Manufacturing Variation in Emitter: Cv = S/Q

= (q₁²+q₂²….+ qn ²-n(q) ²)⅟2 / q(n-1) ⅟2

In Which,Cv = emitter coefficient of manufacturing

variation,q₁, q₂… qn = individual emitter discharge rate

values,N = Number of emitter in sample,Q = Average discharge rate of the emitters

sampled,S = Standard deviation of the discharge rates of

the sample.

Recommended rangers of Cv

(emitter coefficient of manufacturing variation)

<0.05 Excellent

0.05 to 0.07 Average

0.07 to 0.11 Marginal

0.11 to 0.15 Poor

> 0.15 unacceptable

Discharge of Drippers q= khx

In which,q = Discharge of the dripper, volume/timeP= operating pressure, force/areaX= constants for specified emitters

Irrigation water requirement Vm = Kc x Kp x Cc x Ep x A

In which

Vm = Monthly Irrigation water requirement,

Kc = Crop co efficientCc = Canopy factorKp= Pan evaporation factor (0.8)Ep = Normal monthly evaporation A = Area to be irrigated, m2

Capacity of drip irrigation system Q = Vd x T (na x t)

In whichQ = Capacity of drip system,Vd = Daily water requirement,T = Irrigation interval daysna = Water application efficiency

t = Duration

Qp = Q/n Qp = Discharge per plantn = Number of plant

Numbers of Laterals required:For vegetable crops – 1 lateral for each slop.For orchards – 1 to 2 /each row

Number of drippers per plant:(% total area shaded by the tree x area per

tree) / (effective area wetted by a single emitter).

Area irrigated by a dripper :

Ai = (L x S x P) / (100 x Ne )

Ai = Area irrigated, m2

L = Spacing between adjacent plant rows, m S = Spacing between emission points, m P = % of cropped area to be irrigated Ne = Numbers of drippers at each emission

point

Benefits to Farmers :

More than 70% of Indian farmers are small scale operators cultivating plots less than one hectare. Irratic rainfall pattern play havoc into the livelihoods of the small farmers who do not have any alternate supply of water.

CONCLUSION

• Drip irrigation system is an economical and very efficient system of irrigating for vegetables, row crops etc.

• Drip irrigated crops use less water compared to overhead irrigated crops.

• Drip irrigation increase yields

Thank you