Drip

Video by K.Mohanraj and S.Suresh PG Students, Agricultural Extension, TNAU , Coimbatore.

a. FUNCTION The system controls the supply of water to the plants by a network of tubes with water under pressure.

b. EQUIPMENTS / COMPONENTS

• The Head unit consists of a pump or over head tank.
• Mainline 50 mm, 63 mm and 75 mm HDPE or PVC pipes are used
• Submain 45 mm, 50 mm HDPE pipes are used.
• Laterals 12 mm and 16 mm LLDPE pipes are used.
• Drippers - pressure compensating type 2 lph, 4 lph, 8 lph are more suitable
• Filter unit : Sand filter for coarse particle detention. Mesh filter (120 micron) for fine particle detention.
• Fertiliser unit: A fertiliser tank with ventury setup is used for applying liquid or dissolved fertilisers. Pressure gauges 0.5 to 2.5 Ksc and gate valve depending on pipe size are also essential for the system to control and monitor the flow.

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Fertilizer Tank – cost Rs 3500

Fertilizer Tank – cost Rs 3500 Ventury Rs 1250 Fertilizer pump Rs. 12,000

Ventury Rs 1250

Fertilizer pump Rs. 12,000

c. SALIENT FEATURES

• 50 to 65% water saving compared to control method.
• Crop attains early maturity.
• Crop quality and yield increased.
• Requires least land levelling.
• Poor quality water can be used.

Advantages of drip irrigation system (after sailent features)

• High quality and increased fruit size
• Suitable for all types of soil
• Easy method of fertigation and chemigation
• Saving in labour and field preparation cost

Disadvantage of drip irrigation system

• High initial investment
• Clogging of emitters
• Possible damage of system components due to animals, etc.,

Investment cost mostly differs based on spacing of the crops

• Generally, the reasons for clogging are solid particles (sand, rust), soft dirt (organic matter, algae, micro organism, salt), sediments (salt in the fertilizers).
• Filtration is the main key factor to the success or failure of the system. The main of filtration is to stop dirt particles which damage any components of the system.
• To remove salt encrustation, 30 per cent commercial hydrochloric acid can been used at the rate of one liter per one m3 area. (One part HCl mixed with 5 parts of water)
• To remove algae and fungal clogging 5 to 500 ppm sodium hydrochloride (10 per cent chlorine) can be used.

Maintenance of drip system

• Back washing and sand filters has to be cleaned
• Frequent cleaning of emitters and drippers
• Flushing at every irrigation
• Cleaning of sub main and main pipes
• Cleaning of PVC pipes and laterals and acid or chlorine may be used to remove clogging.

Water used and yield of crops in micro and conventional irrigation methods

Banana

97.00

45.00

87500

52.00

90.20

Surface

176.00

57500

32.67

Sugarcane

94.00

56.00

170000

33.00

180.85

Furrow

215.00

128000

59.53

Grapes

27.80

48.00

32500

3250

23.00

116.90

53.20

26400

49.62

Aerobic rice

Conventional aerobic rice

74.30

38.10

4747

6.39

Surface drip

61.90

48.40

5940

14.20

9.60

Sub-surfacedrip

6227

19.80

9.74

Conventional transplanted

120.00

20.00

5200

4.33

Cotton

28.00

66.27

25.00

116.10

83.00

2600

31.33

Beetroot

17.70

79.34

887

55.34

50.11

85.70

571

6.66

Radish

10.80

75.72

1186

13.49

109.80

46.40

1045

22.52

Papaya

73.88

67.89

23490

69.47

0.32

225.80

13860

1386

0.06

Mulberry

60.00

71400

3.03

3570

50.00

69300

Tomato

18.40

39.00

48000

260.86

30.00

32000

106.66

(WTC Annual Reports 1985-2003)

d. COST Water requirement (lit/day), increase in yield, water saving (percent), lateral spacing and cost are given in Table (1).

Table 1. Water Saving, Yield Benefits, Lateral spacing and Cost in drip system

Table 1. Water Saving, Yield Benefits, Lateral spacing and Cost in drip system Crops Water Requirement lpd/plant Percentage Lateral Spacing (m) Cost Rs. / ha Drip Conventional Increase in yield Water saving Coconut 75 –100 200 - 300 30 45 7.5 30,000 Grapes 25 - 45 90 -100 23 48 3.0 50,000 Mango 30 - 50 90 -150 23 40 10.0 28,000 Guava 22 - 30 70 -100 40 50 5.0 34,000 Sapota 20 - 30 70 -100 40 50 10.0 28,000 Pomegranate 20 - 40 60 - 130 98 45 5.0 34,000 Banana 8 –12 30 - 40 52 45 2.0 56,000 Lemon 10 - 20 25 - 65 40 60 3.0 50,000 Papaya 5 – 8 18 - 26 75 68 2.0 56,000 Brinjal 1 – 2 4 - 8 14 53 1.20 75,000 Bhendi 1 – 2 4 - 6 16 40 1.20 75,000 Tomato 1 – 2 4 - 6 50 39 1.20 75,000 Chillies 1 – 2 3 - 6 44 62 1.20 75,000 Gourds 1 – 2 3 - 6 15 54 1.20 75,000

Source : Crop Production Guide 2012 (Agriculture)