Micro irrigation for enhancing water productivity in field crops

Shantappa DuttarganviII year Ph. DPHD11AGR1007

Introduction

Irrigation scenario

Classification

Drip irrigation

Sprinkler irrigation

Conclusion

LEPA & LESA

Geographical area 329 Gross cultivable area 190 Gross irrigated area 76 Net irrigated area 56

(m ha)

Ratio Kharif RabiNet Sown area to operational land (%) 87 57Irrigated Land to Net Sown Area (%) 42 67

Micro irrigation area in different states (2010)Micro irrigation area in different states (2010)

Source : Proceedings of national seminar on advances in micro irrigation, 2011

Area under micro-irrigation in the Area under micro-irrigation in the worldworld

7th International micro-irrigation congress, 2011

Delivery of water at low flow rates through various types Delivery of water at low flow rates through various types of water applicators by a distribution system located on of water applicators by a distribution system located on the soil surface, beneath the surface or suspended above the soil surface, beneath the surface or suspended above the groundthe ground

Apply water in precise:

◦ Time◦ Location◦ Quantity

Advantages of micro irrigation Water & fertilizer operating cost savings

Ability to apply saline water

Operate on steep slopes and rough terrain

Reduced evaporation & soil water near FC

Easy to automate

Adaptable for chemigationAdaptable for chemigation

Reduced weed growth and disease problemsReduced weed growth and disease problems

High initial costHigh initial cost

Susceptible to clogging

Ponding & runoff on heavy soils

May require better management

Restricted root developmentRestricted root development

Hilly /Undulating

Areas

Deserts

Saline Water

With Major/ Medium

Irrigation

Fruits Vegetables

Forests

Flowers

Cereals

Oilseeds

Pulses Cotton

Spices

Sugarcane

Micro Irrigation

Components of micro irrigation Components of micro irrigation systemsystem

Source: Jain irrigation

Types of Micro irrigation systems

Types of micro-irrigation Drip irrigation Surface drip & Subsurface drip Sprinkler irrigation

Rotating head system Perforated pipe system Based on portability

Portable & Semi portable system Solid set system & Permanent system

LEPA (Low- elevation precision applicators)LESA (Low energy spray applicators)

Drip Irrigation

Surface dripWater applied through small emitter openings

(<3 gal/hr/emitter)Most prevalent type of micro irrigationCan inspect, check wetting patterns and

measure emitter discharges

Subsurface dripWater applied through small emitter openings below

the soil surfaceBasically a surface system that's been buried

(few inches to a couple feet)Permanent installation

SUBSURFACE DRIP IRRIGATION

Advantages High & uniform water application Lower pressure & power requirements No dry corners Adaptable to automation

Disadvantages High initial cost Water filtration required Complex maintenance requirements

Flushing, Chlorination and Acid injection

Emitter Layouts

Many configurations are designed to increase per cent of wetted area

Rate of flow per lateral & total pipe length

Point source Line source

Classification of drip lines

Point source system-online drippers The emitters are inserted on the outside of the distribution line Here the emitters work under a pressure of 0.5 to 1.5 kg/cm2 with a flow rate of 2 to 8 lph

LINE SOURCE SYSTEM/INLINE DRIPPERS

Drippers are inserted into the tube at the time of manufacturing the lateral tubes in the factory The drippers are inserted at desired intervals as per the crop and soil requirements Line source emitters are suitable for close grown row crops and in gardens The dripper spacing is more with a discharge ranging from less than 1 to 4 lph

Its major disadvantage is the difficulty in de clogging

Nutrient distribution pattern

Trenching across the drip tubing for PVC pipe installationTrenching across the drip tubing for PVC pipe installation

Drip irrigation system to the field

Economic comparison of drip and furrow Economic comparison of drip and furrow irrigation methodsirrigation methods

Economic activity evaluated for each scenario

Drip Irrigated Percentage as Compared to the Same Furrow-Irrigated Farm Model, 2000

Yield +25%

Chemicals -18%

Fertilizer -26%

Capital +47%

Fixed costs +19%

Net operating profit +12%

Jerry, 2010

EFFECT OF DRIP FERTIGATION ON YIELD AND WATER PRODUCTIVITY OF MAIZE

Ponnuswamy and Santhi (2008)Coimbatore

Grain yield and Water use efficiency (WUE) of Green gram under drip irrigation

TreatmentGrain yield

(kg/ha)Straw yield

(kg/ha)Quantity of water (mm)

WUE

(kg/ha mm)

IW/CPE ratio

I1: 0.30 545 1794 130 4.61

I2: 0.45 695 2231 180 4.52

I3: 0.60 962 3076 280 4.36

I4: 0.75 1102 3423 330 4.34

CD at 5% 92.08 295.72 - -

Patel et al. (1996)Gujarat

Effect of drip irrigation on yield, oil content and WUE of Sunflower

TreatmentSeed yield

(q/ha)

Stover yield (q/ha)

Total water used (mm)

Oil content (%)

WUE

(kg/ha-mm)

Drip at 0.5 Epan

35.25 35.00 412.85 42.19 8.54

Drip at 0.6 Epan

35.84 38.09 457.68 41.70 7.81

Drip at 0.8 Epan

30.87 34.70 548.64 40.96 5.62

Weekly surface irrigation at 0.8 Epan

31.75 33.40 548.64 41.37 5.79

CD at 5% 1.29 NS - 0.78 0.260

Bangalore Shivakumar et al. (2000)

Effect of irrigation methods on quality parameters, water-use efficiency and yield of Cotton

TreatmentSeed index (%)

Lint index

(g)

Oil content

(%)

Seed cotton yield

(kg/ha)

WUE (kg/ha-

mm)

Total water

applied (mm)

Saving of water surface method

(%)

Drip0.4 CPE

5.39 3.52 18.8 1096 3.01 364 46.2

Drip0.6 CPE

5.79 3.76 19.8 1431 3.05 471 30.9

Drip0.8 CPE

6.10 3.83 20.0 1535 2.67 578 14.5

Alternate furrow

5.75 3.65 19.0 1348 3.33 413 38.9

Surface irrigation

5.83 3.67 19.1 1375 2.02 675 -

CD at 5% 0.39 0.12 0.16 92 0.20 - -

Sagarka et al., 2002

Irrigation requirement = crop water requirement – effective rainfall

Sprinkler Irrigation

Micro spray/ micro jets

Discharge: 1gal/min/spray applicator Low operating pressure requirements of from 0.8 to 1.5

kg/cm2, low water application rates and suitability for stony or very coarse sandy soils

Objective: To emit water in the form of small droplets without causing any misting

• These are highly useful for high discharge requirements in case of orchards and also where the crop canopy as well as the root zone spread is more

• They are normally, designed to spray water to cover an area of 1 to 6 meters with a flow rate varying from 20 lph to 120 lph

RAIN GUN

Most suitable for a variety of climates like tropical, temperate and humid climates as in India

Light in weight and easy to install Uniform distribution profile with adjustable jet Long life span and low maintenance Better pattern coverage & good performance in

windy conditions

Effect of micro sprinkler irrigation on yield and water productivity of Groundnut

Effect of micro sprinkler irrigation on yield and water productivity of Groundnut

TreatmentsYield

(kg/ha)Total water used

(mm)WUE

(kg/ha-mm)Surface method 2797 409.2 6.8Micro sprinkler 100% PE 2860 558.1 5.12Micro sprinkler 80% PE 3823 510.7 7.48Micro sprinkler 60% PE 3407 467.6 7.29Micro sprinkler 40% PE 2992 412 7.26Micro sprinkler 100% ETc

3324 502.28 6.62

Micro sprinkler 80% ETc 3130 462.46 6.77Micro sprinkler 60% ETc 3047 426.26 7.15Micro sprinkler 40% ETc 2770 379.55 5.85CD at 5% 153    Krishnamurthi et al., 2003Bhavanisagar (TN)

Growth and yield attributes of Chilli as influenced by micro- irrigation systems

TreatmentsPlant height at harvest

(cm)

No. of

branches/plant at harvest

Yield of chilli (t/ha)

T1-Control 78.5 11.9 8.19

T2-Rotary micro-sprinkler

87.9 15.8 11.05

T3- Stationary micro-sprinkler

80.4 15.2 10.60

T4-Strip tape 77.5 13.9 9.90

T5-Turbokey 79.2 15.0 10.21

T6- Micro-tube 78.8 12.5 9.86

S.E. ± 2.99 0.51 0.08

CD at 5% 8.87 1.50 0.25Shinde et al.,1999

Average cotton yields and water application comparisons

Irrigation system

Cotton yields lint (lb/acre)

Water applied (Inches)

Yield to water use ratio (lb/inch)

Furrow 1350 65 20.0

Sprinkler 1200 42 29.0

Drip 1890 32 59.0

Howard Wuertz, 2010

LEPA & LESA

LEPA

(Low- elevation precision applicators)

95 to 98% efficiency

LESA (Low energy spray applicators) Efficiency 90%

Schneider, 2000

Depth of soil-water content at different irrigation regimes and in different micro-irrigation methods

Medium-low Elevation Spray ApplicationLow- Elevation Spray ApplicationLow –Elevation precision ApplicationSub- Surface Drip Irrigation

Selection of the Systems

SELECTION OF THE SYSTEMS

Contd…

Possibilities of adapting micro irrigationPossibilities of adapting micro irrigation

Drip irrigationAll type of crops

except some close spaced crops

Well and tank irrigation

Suitable for all types of soils – sandy, clay and saline

Sprinkler irrigationClose spaced

cropsWell, tank and

canal irrigationSuitable for all

types of soils – coarse sandy soils

Salt movement under irrigation with saline waterSalt movement under irrigation with saline water

Salt accumulation leached downward by successive water applications

Salt accumulation leached Salt accumulation leached radially outward from drip radially outward from drip tubingtubing

Subsurface DripSubsurface Drip Sprinkler/FloodSprinkler/Flood

Surface 30 - 40%Sprinkler 60 - 70%Drip irrigation 80 - 90%

Comparative efficiency of irrigation systems

Relative Irrigation Efficiencies (%) under Relative Irrigation Efficiencies (%) under Different Methods of irrigationDifferent Methods of irrigation

Sivanappan, 1997

Effect of micro irrigation in different crops on water saving and crop Effect of micro irrigation in different crops on water saving and crop yield (from past research studies)yield (from past research studies)

Name of researcher Location Crop Water saving Crop yield

Jadhav et al. (1990) Haryana Tomato 31% 50%

Hapase et al.(1992) Maharashtra Sugarcane 50-55% 12-37%

Reddy and Thimmegowda(1997)

Bangalore Cotton 13-16%

Shiyani et al. (1999) Gujarat Cotton 25% 22-26%

Anitta Fanish and Muthukrishnan(2011)

Coimbatore Maize 32-43% 35-39%

Ramachandrappa and Havanagi(1983)

BangaloreRed gram,

Cotton51% 24, 49, 131%

Anon. (1993) Junagadh Groundnut 42% 40-46%

Veeraputhiran et al. (2012) Madurai Sugarcane 31% 30-33%

Sagarkar et al. (2002) Gujarat Cotton 38-46%

Rajendran et al. (2012) Coimbatore Cotton 30-36% 25-27%

Vijayalaksmi et al. (2003) Madurai Groundnut 30-38% 50-55%

Kahlowan et al. (2006) Lahore(Pakistan) Rice, Wheat 26-35%

MAINTAINANCE OF MICRO IRRIGATION EQUIPMENTS

DESIGN AND MANAGEMENT DESIGN AND MANAGEMENT ISSUESISSUES

 CloggingClogging Physical (mineral particles)Physical (mineral particles) Chemical (precipitation)Chemical (precipitation) Biological (slimes, algae, etc.)Biological (slimes, algae, etc.)

Chlorination

When the source of irrigation water is a dam, river, irrigation channel, etc., chlorination is recommended which kills bacteria, algae and other organic matter.

Acidification

Injection of 30% HCl is recommended for removal of precipitated calcium salts on the inner surface of the drip system.

Types of filtration systems Types of filtration systems

Back washing in sand filters Filters

Dublin Principles (ICWE, 1992)Dublin Principles (ICWE, 1992)Freshwater is a finite vulnerable resource, essential to

sustain life, development and environment

Water development and management should be based on a participatory approach involving users, planners and policy makers at all levels

Women play a central part in the provision, management and safeguarding of water

Water has an economic value in all its competing uses and should be recognized as an economic good

Future line of workFuture line of work

Creating awareness about importance of improving water productivity through micro irrigation is need of the hour

Need for development of low cost micro irrigation systems for wider adaptability

Optimization of level of nutrients and irrigation water through micro irrigation in different crops

Creating awareness about importance of improving water productivity through micro irrigation is need of the hour

Need for development of low cost micro irrigation systems for wider adaptability

Optimization of level of nutrients and irrigation water through micro irrigation in different crops

Conclusion