WATER TECHNOLOGY CENTRE,TNAU
Trend in Net area irrigated (Lakh ha) in Tamil Nadu Sources
1970
2003
8.8
8.1
(35.6)
(30.3)
9.1
6.0
(36.8)
(22.4)
6.5
12.6
(26.0)
(46.7)
0.4
0.2
(1.6)
(0.6)
Total
24.8
26.9
Irrigation intensity (%) Figures in parenthesis are percentage
131
123
Canals Tanks W ells O thers (Springs, Channels)
Groundwater Status in Tamil Nadu Particulars
No. of Blocks
Dark
87
Grey
83
White
215
Total
385
Tamil Nadu : Supply - Demand GAP for Water in 2025
Particulars Qty in MHM Water supply 4.7 Water Demand 6.9 Agri 5.2 Non-Agri 1.7 Supply-Demand gap -2.2
Strategies‌ | Water
saving technologies for increasing water use efficiency |
Drip irrigation
|
Drip fertigation
Nutrient distribution pattern Surface irrigation
Leaching
Drip
Localised
Drip fertigation
Uniform
Fertilizer Use Efficiency Fertilizer Use Efficiency (%) Nutrient
Soil appln.
Drip
Drip Fertign.*
30-50
65
95
Phosphorous
20
30
45
Potassium
50
60
80
Nitrogen
* 95% applied fertilizer taken by plants
Fertilizers for fertigation Name
Rate (Rs./kg)
SPECIALITY WATER SOLUBLE FERTILIZERS Poly feed
(19-19-19)
52.0
MAP
(12-61-0)
56.0
Multi 窶適
(13-0-46)
40.0
MKP
(0-52-34)
75.0
SOP
(0-0-50)
34.0
NORMAL FERTILIZERS Urea
(46-0-0)
4.6
Potash
(0-0-60)
4.4
Devices for fertigation
Fert. Tank
Ventury
Fert. Pump
Cost: Rs.3500
Rs.1250
Rs.12000
Fertigation in Sugarcane with Water Soluble Speciality Fertilizers
Fertigation with water soluble fertilizers in Banana (Nendran)
Tomato fruiting with water soluble speciality fertilizers
Cost benefits, Payback periods of Micro irrigation for various crops Spacing of crops m
Cost of the system Rs.ha-1
Pay back period
B:C ratio
0.91*1.5*1.8 paired row
45,000
1-2 Year
3.00
3.03*1.8
44,000
1 Year
3.28
Pomegranate
4.3*4.3
30,000
2 Year
5.16
Ber
4.5*4.5
30,000
1 Year
4.56
Tomato
0.45*0.45* 1.65 Paired row
30,000 canewall
1 Year
1.09
Papaya
1.81*1.81
40,000
2 Year
4.09
Cotton
0.9*1.5*1.8 Paired row
47,500
3 Years
1.83
0.83*1.66 Paired row
47,500
1 –2 Year
3.45
Crops Banana Grape
Sugarcane
Water saving,yield and profit under drip and drip fertigation system
Crops Banana Sugarcane Tomato
Yield (t/ha) Profit (Rs/ha) Water saving Conventi Drip + Conventi Drip + Drip Drip (%) onal Fertgn onal Fertgn
35 29 32
26 120 45
30 160 56
Payback Period 1-2 years
37 207 65
81000 30000 56000
98000 120000 47000 68000 77000 95000
ISSUES: 1. COST REDUCTION
Banana: Drip - Normal planting method
Drip system cost Rs.45000/ha
Drip system under paired row method
Drip system cost Rs.35000/ha
Paired row - Drip lay out in sugarcane
TURMERIC -
COST REDUCTION IN DRIP LAY OUT WITH MICRO TUBES
Paired row with micro tubes in tapioca
Bucket Kit System configuration Bucket (20 ltrs) 1 No 12 mm Lateral line 1 No (with filter, tap & 26 micro tubes)
Bucket Gromet & Take off Valve Line filter
Microtube coverage
Micro tube End cap 12 mm lateral line
Drum Kit Microtube coverage
Tap Filter
16 mm sub main Reducer tee 12 mm lateral Cap Micro tube
System configuration
Plants 2m
Wetting pattern
16 mm lateral line (with 5 trees) 1 No 12 mm lateral line (with 130 micro tubes) 5 Nos
Micro Sprinkler Kit Existing water source Valve Filter
System configuration 16 mm lateral (fitted with tees) 1 No Laterals (with connections for sprinklers) 5 Nos Micro sprinklers 15 Nos
Micro sprinkler
coverage
ISSUES 2. DRIP SYSTEM MAINTANENCE
MAINTENANCE OF DRIP IRRIGATION EQUIPMENT 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. Example: Pump discharge is 20 cu.m/hr Irrigation time is 5 hr Rate of chlorine required is 5 ppm (mg/l) 1ppm=1g/cu.m (1000 litres), 5 ppm = 0.2 kg chlorine/hr = 2 kg as 10% Sodium hypochlorite/hr, therefore total Na hypochlorite required 5 hr x 2 = 10 kg.
MAINTENANCE OF DRIP IRRIGATION EQUIPMENT ACIDIFICATION Injection of 30% HCl is recommended for removal of precipitated calcium salts on the inner surface of the drip system Example: Pump discharge : 20 cu. M/hr Max injector pump discharge : 250 litres/hr Acid required : 20 litres (1 litre per cu.m.) Total solution required : 250/10 = 25 litres (1/10th of the discharge) Water quantity to use : 25 – 20 = 5 litres
Sand Filter Backwashing
Flushing of Submains and Laterals
Issues 3. Subsidy Rate of subsidy - 25% Subsidy at Govt. fixed unit cost Energy Saving = Subsidy ¾ Banana Rs. 5100/ha ¾ Sugarcane Rs. 4500/ha ¾ Grapes Rs. 2250/ha ¾ Coconut Rs. 2000/ha
ISSUES : 4. DRIP Vs TAP SYSTEM a. Saline water b. Limited water and power supply c. Cost saving in Tap Dripper : 4 / tree @ 8 LPH * 3 Hr = 96 L / tree/day Cost : @ Rs 2.35/dripper * 175*4 = Rs 1645/ha Tap : 1/ tree @ 100 LPH *1Hr = 100L/tree/day Cost: @ Rs 0.8/tap * 175 = Rs 140/ha
Issues 5. Area Expansion
• Additional area under drip irrigation (5% of the present cropped area) • Expanding drip fertigation (2.5% of the present cropped area)
1.Drip cost at 5% additional area
Crop
Current Area (lakh ha)
Proposed area under drip (ha) (5% )
Total drip cost (Rs. Crores)
Govt. subsidy at 50% (Rs. Crores)
Sugarcane
2.83
14140
91.9
45.9
Coconut
2.70
13500
37.8
18.9
Vegetables
2.15
10770
0.6
0.3
Mango
0.90
4512
10.8
5.4
Cashew
0.84
4210
11.8
5.9
Others
1.86
9289.5
45.9
22.9
11.28
56420
198.8
99.3
Total
2.Drip fertigation cost at 2.5% additional area Crop
Current Area (lakh ha)
Expected area (ha) under drip fertigation (2.5% )
Total drip cost (Rs. Crores)
Total cost for fertigation device (Rs. Crores)
Total drip+fertig ation device cost (Rs. Crores)
Govt subsidy at 50% (Rs. Crores)
Sugarcane
2.83
7070
46.0
2.1
48.1
24.0
Coconut
2.70
6750
18.9
2.0
20.9
10.4
Vegetables
2.15
5385
32.3
1.6
33.9
17.0
Mango
0.90
2256
5.4
0.7
6.1
3.0
Cashew
0.84
2105
5.9
0.6
6.5
3.3
Others
1.86
4645
23.0
1.3
24.4
12.2
11.28
28210
131.5
8.4
139.9
69.9
Total
How to go ahead ? 1.Tamil Nadu Agrl. University Role: Planning, Monitoring and Evaluation 2.Agril.Engg. and Horticulture Depts. Role: Drip and fertigation system installation, technical support and TOT 3.Industries Role: Developing Linkages for TOT and quality control.
TNAU Experiences 1. Irrigation Cafeteria
2. Adaptive Research Trials
3. Village Adoption