3. LITERATURE SURVEY - Shodhganga : a reservoir of …shodhganga.inflibnet.ac.in/bitstream/10603/2209/13/13_chapter 3.pdf · 3. LITERATURE SURVEY ... (Annual report of NCPA, 1990

3. LITERATURE SURVEY

Irrigation advancements within the last 3 decades have been

astounding. Microirrigation is one of the latest innovations for

applying water and it represents a definite advancement in irrigation

technology. It can be defined as frequent application of small quantity

of water directly, above or below the soil surface; usually as discrete

drops, continuous drops, tiny streams, or as miniature sprays

through mechanical devices called emitters or applicators, located at

selected points along water delivery line. Types of microirrigation

systems include surface drip, subsurface drip, spray irrigation and

bubbler irrigation. The surface drip includes both online drip system

and integral drip line system.

Many reports have cited and summarized potential impacts of

drip irrigation compared to other methods. (Annual report of NCPA,

1990 and Sivanappan, 1998). In this chapter an attempt has been

made to discuss the literature pertaining to the impact of adoption of

surface drip on crop yields, water, power and fertilizer savings; and

economics only, since most of the area covered under Andhra Pradesh

Microirrigation project (present study area) was under drip irrigation.

3.1 IMPACT OF SURFACE DRIP IRRIGATION ON CROP YIELDS

3.1.1 Fruit Crops

Improved crop yields with the adoption of drip irrigation were

reported by several researchers in fruit crops (Sivanappan, 1987;

Narayanamoorthy, 2004; Srinivas and Hedge, 1990).

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3.1.1.1 Banana

In banana adoption of surface drip irrigation increased the fruit

yield from 6 to 10% over flood irrigation (78.98 t/ha) in Bangalore

(Hedge and Srinivas, 1990). Likewise Bendale et al. (1998) reported

that the improvement in fruit yield of banana was 22% (89.10 t/ha)

with drip irrigation as compared to flood irrigation in Sangli region of

Maharastra. While others, notably reported 12% increase (Magar,

1985); 15% increase (Pawar et al., 2001); and (Narayanamoorthy,

2004) 23% increase in fruit yield of banana over conventional surface

method of irrigation.

Singh et al. (1993) found an increased yield of 52% with drip

irrigation (87.5t/ha) at Pantnagar. Likewise Taley et al. (1996)

reported an increased yield of 50% (75 t/ha) with drip irrigation over

flood irrigation at Akola.

From Coimbatore, Sivanappan (1994) reported increased yields

of 34% with drip irrigation (57.5t/ha) compared to flood irrigation. The

studies conducted by NCPA at various locations in India also revealed

similar increase in banana fruit yield (Annual report of NCPA, 1990).

The research studies conducted at Bhavanisagar, Tamil Nadu (Annual

report of WMS, 1997) revealed an increased banana yield of 27.3%

with drip irrigation over flood irrigation.

Microirrigation scheduling studies conducted by Salvin et al.

(2000) in banana registered highest yield of 44.0 tons/ha at 75%

evaporation replenishment, while the lowest yield of 26.12 tons/ha

30

was observed with out any irrigation. Thus from the above review it

can be summarized that impact of adoption of drip irrigation in

banana proved to be positive in many agro-climatic zones of India and

varied from 6 to 52% in comparison to surface methods of irrigation.

3.1.1.2 Papaya

In Papaya the increase in yield with the adoption of drip varied

between 30 to 75% over surface methods of irrigation (Sivanappan,

1988). Padmakumari and Sivanappan (1983) found 43% increase in

fruit yield; Singh et al. (1993) found 75% increase in fruit yield;

Srinivas (1996) found 30% and Suresh and Saha (2004) found 37%

increase in fruit yield of papaya over surface methods. The work of

Sivanappan (1994) indicated that the increase in yield could be 45%

with drip irrigation over basin irrigation.

3.1.1.3 Mango

The studies conducted at Indian Institute of Horticultural

Research, Bangalore on mango by Srinivas (1999) revealed an

increased fruit yield of 14.7% to 23.2% over basin irrigation. Where

as, Shukla et al. (2000) found improvement in yield by 61% (21 t/ha)

under drip over basin irrigation at Pantnagar. Likewise Mane et al.

(2002) found 58.1% increased mango yields over basin irrigation in

Konkan region. Dixit et al. (2003) studied the performance of mango

under drip irrigation with mulching at Haryana Agriculture University,

Hissar and reported significantly higher yield of 28.9 t/ha. Likewise

Agarwal et al. (2005) reported that drip irrigation with plastic mulch

31

registered highest yield of 29.80 tons/ha. Bhandarkar et al. (2005)

scheduled irrigations in mango based on climatological approach at

80% replenishment of evapo-transpiration and found higher yields

ranging from 31 to 32% over no irrigation. Similarly Sujatha et al.

(2005) reported that drip irrigation at 0.75 of pan evaporation rates

recorded significantly higher mango fruit yield of 44.9 kg/tree than no

irrigation (18.4 kg/tree). Patel et al. (2005) reported that in mango the

drip irrigation resulted in increased yield by 52% over surface

conventional basin irrigation.

Farre and Hermoso (1993) stated that in mango drip irrigation

with mulching resulted in increased yield of 12.9 Kg/plant compared

to 11.1 Kg/plant under flood irrigation.

3.1.1.4 Pomegranate

Reviews by Sivanappan (1994) and INCID (1994) indicated yield

increase in pomegranate to the tune of 50% by adoption of drip

irrigation as compared to conventional basin irrigation in Tamilnadu.

Where as Singh et al. (1993) found an increase of 98% at Pantnagar.

On the other hand Magar (1985) stated 43% improvement in yield

than conventional irrigation (11.3t/ha) in Maharastra. Chopade and

Gorantiwar (1998) reported that yield differed significantly between

drip and basin and potential yields of 65.53 q/ha were recorded with

drip irrigation. Similarly Behnia (1999) reported that drip irrigation in

pomegranate improved the yield by 21-24.5%. Studies of Firake and

Kumbhar (2002) suggested that about 36% increased yield was

32

obtained with drip irrigation over surface basin irrigation. Prasad et

al. (2003) from Rajasthan stated that in pomegranate the yield

increase was 59.3% with drip irrigation (28.2 kg/plant) compared to

basin method. Similar observations were made by Sulochanamma et

al. (2005) from Andhra Pradesh. Prabhakar et al. (2006) reported that

in pomegranate drip fertigation with recommended dose recorded a

higher yield (14.89 kg/plant) with more number of fruits per plant.

3.1.1.5 Citrus Spp

Singh et al. (1993) reported that in sweet orange the adoption of

drip irrigation resulted in increased yield by 50% (150 t/ha) over

basin irrigation. Subhash and Satish Kumar (1996) reported 39%

highest yield over basin irrigation in Kagzi lime with drip irrigation.

Similar observations were made by Manjunatha et al. (2001) and

Rajbir Singh et al. (2001). Shirgure et al. (2003) found that in Nagpur,

mandarin fruit yield with different microirrigation systems was

significantly higher (48.23 to 58.93 kg per tree) than basin irrigation

(32.30 kg per tree).

3.1.1.6 Other Fruits

Singh et al. (1993) reported an increased yield of 23% in grapes

with the adoption of drip irrigation (32.5 t/ha) over conventional

irrigation. Similarly results of NCPA experiments, revealed a yield

increase ranging between 16 to 33% over conventional basin irrigation

(Magar, 1985; Shikhamany and Srinivas, 1999; Sivanappan, 1994;

and Narayanamoorthy, 2004).

33

Palanichamy et al. (2002) stated that in coconut the yield

increase was 20-30% with the adoption of drip irrigation (90

nuts/tree) over basin irrigation. Similar results were recorded by

Muthuchamy et al. (1998) and Dhanpal et al. (1998).

In other fruits like guava, custard apple and water melon drip

irrigation was shown to increase yields ranging between 20 to 88%

(INCID, 1994 and Srinivas, 2001). Singh et al. (2005) stated that the

guava grown with drip irrigation increased yields by 28.5% over

normal basin irrigation.

3.1.2 Vegetables

3.1.2.1 Brinjal

Adoption of drip irrigation in brinjal resulted in increased yield

in comparison to flood irrigation method which varied from 4% to 39%

under different agro-climatic conditions (Annual report of NCPA,

1990). Padma Kumari and Sivanappan (1978) reported an increase of

4% yield over furrow irrigation. Similar increase in brinjal yields were

reported by several workers - up to 7% (Anonymous,1984) at Rahuri,

up to 30% (Tefera.,1987) at Pantnagar, Prabhakar and Hebber (1996)

up to 17% at UAS, Dharwad, Singh et al. (1993) up to 38% at

pantnagar, Magar (1985) up to 14% at Maharastra, Manjunatha et al.

(2001) up to 17% at Pantnagar, Raman et al. (2001) up to 17% at

Navsari, Pantnagar and Chauhan (2001) up to16% at Pantnagar.

34

3.1.2.2 Tomato

Prabhakar et al. (1996) reported an increased yield of 7% with

drip over surface furrow irrigation (52.8 t/ha) in tomato at UAS,

Dharwad. Similarly Asokaraja (1998) reported 38% of increased

tomato fruit yields over surface irrigation in Tamilnadu. On the other

hand Sivanappan and Padmakumari (1980) found substantial

increase of 43 to 84 % yield over furrow irrigation in Coimbatore. The

results of Panda and Srivastava (1998) were in agreement with the

above observations.

Raina et al. (1998) reported that drip irrigation resulted

significantly higher fruit yield (16.6 tons/ha) 26% than surface furrow

irrigation. Similar increase in tomato yields were also reported by

Pratap singh (2001) up to 21% at Hissar, Manjunatha et al. (2001) up

to 23% at Pantnagar, at PDKV, Akola up to 22%, Annual report of

NCPA Pune up to 57%, Chauhan (2001) up to 22% at Pantnagar,

Raman et al. (2001) up to 41% at Navsari, Pantnagar, Singh et al.

(1993) up to 50% at Pantnagar, and Nageswara Rao et al. (2005) up

to 55%.

3.1.2.3 Chillies

The adoption of drip irrigation in chillies resulted in increased

yields which varied from 3 to 44% over surface furrow irrigation.

Veeranna et al. (2001) recorded an increase of 9% with the adoption of

drip irrigation over furrow method in Bangalore; where as Singh et al.

(1993) found an increase of 44% yield with drip irrigation over

35

traditional flood method (4.2t/ha) in Pantnagar. Likewise the

increased yields in chillies were also reported by Raman et al. (2001)

up to 12% at Navsari, Manjunatha et al. (2001) up to 9% at

Pantnagar, Sivanappan and Padmakumari (1980) up to 30% at

Coimbatore, (Singh et al., 1999; Singh and Anurag Saxena , 2001) up

to 71% at Jodhpur, and NCPA (1990) up to 31%.

Swarajya Lakshmi et al. (2005) from Hyderabad reported that

drip irrigation in green chillies recorded an increase of 34% yield than

traditional flood method.

3.1.2.4 Other vegetables

Adoption of drip irrigation in several vegetables recorded

increased yields over flood irrigation. Sivanappan and Padmakumari

(1980) from Tamilnadu reported an increased yield of 13% in bhendi,

13% in radish, 33% in beetroot, and 28% in sweet potato with drip

irrigation over traditional irrigation method. Similarly Singh et al.

(1993) at Pantnagar reported increased yields in case of cabbage by

75%, radish by 13%, and in sweet potato by 39% over conventional

furrow irrigation.

3.1.3 Sugarcane

Adoption of drip irrigation in sugarcane resulted in increased

yield over flood irrigation (Sivanappan, 1998). Batta et al. (1998) from

Maharastra reported an increase of 12 to 25% yield of sugarcane with

drip irrigation over surface method of irrigation. On the other hand

Dhindwal et al. (1999) from Maharastra registered an increased yield

36

of 16-18% compared to flood irrigation. Shinde et al. (1998) from

Pune stated that, the pressure compensating and inline drip irrigation

systems were effective and increased cane yield by 17.42 to 20.32%

compared to furrow irrigation. Similarly Narayanamoorthy (2004a)

registered the increased yield of 20% - 25% over flood irrigation in

Maharastra. Similarly the increased yield of 17% was reported by

Anonymous (1984) at Rahuri and 24% increased yield was reported by

Selvaraj et al. (1997) at Bhavanisagar, Tamilnadu in sugarcane.

Mahendran et al. (2002) reported that the drip fertigation at

100% IW/CPE in two row planting system registered the highest cane

yield of 202 t/ha compared to a lowest cane yield of 144 t/ha with

surface flood irrigation.

3.2 IMPACT OF SURFACE DRIP IRRIGATION ON WATER SAVINGS

In traditional types of surface irrigation, huge amount of water

is lost through seepage and deep percolation while conveying water

from the source to field. Whereas in case of drip systems the water is

applied to the root zone of the crop in smaller droplets which results

in less losses of water and improved water use efficiency (Rajbir singh

et al., 2001). Narayanamoorthy (2004) in Maharastra registered a

water saving of 12 – 84% in vegetables, 45-81% in fruit crops and 40 –

60% in field crops like cotton and groundnut; and 65% in sugarcane

with the adoption of drip irrigation over conventional surface

irrigation.

37

3.2.1 Fruits

Adoption of drip irrigation resulted in a substantial saving of

water which varied from 45 to 68% depending on crop and situation

over surface irrigation (NCPA, 1990).

3.2.1.1 Banana

Hedge and Srinivas (1990) registered a water saving of 25 % in

banana with drip irrigation over furrow irrigation (1600 mm). The

research studies conducted at Bhavanisagar, Tamil Nadu (WMS,

1997) revealed water saving of 41.6% in banana with drip irrigation.

Similar results of water savings ranging between 42-45% were

reported by Salvin et al. (2000) and Sivanappan (1994) in Tamilnadu.

Srinivas (1999) reported that the drip irrigation with water equivalent

to 80% of evaporation replenishment resulted in 42% water saving

with drip irrigation (1000 mm) in banana Robusta variety.

Narayanamoorthy (2004) reported water saving of 29% with drip

irrigation over flood irrigation in banana. Likewise Magar (1985)

reported water savings of 42% in Maharastra with drip irrigation over

furrow irrigation. On the other hand Pawar et al. (2001) found 23% of

water savings at MPKV Rahuri with drip irrigation over furrow

irrigation (347 mm).

Rajkumar et al. (2003) reported that for banana, water

consumption is less in case of drip irrigation (970 mm) as compared

with surface irrigation (1760 mm) resulting in 56% saving of water.

38

3.2.1.2 Mango

Bangal (1987) reported a saving of 55% of water in mango with

drip irrigation compared to basin irrigation method. Similar

observations were made by Ravi Babu et al. (1996) and

Balasubrahmanyam et al. (1999, 2001) for mango. Shukla et al.

(2000) reported water saving of 58% at Pantnagar with drip irrigation

in mango compared to conventional basin irrigation (3720 mm).

Srinivas (1999) observed improvement in number and weight of

mango fruits with irrigation schedules at an evaporation

replenishment rate of 60% using drip irrigation.

3.2.1.3 Sweet orange

Rajbir Singh et al. (2001) recorded 35% of water saving in sweet

orange compared to basin irrigation (1260 mm) under Punjab agro-

climatic conditions. On the other hand Manjunatha et al. (2001)

registered 25% of water saving with local practice of ditch irrigation in

sweet lime. Similarly Shirgure et al. (2001, 2003) reported that in

Nagpur, mandarin crop consumed comparatively higher quantity of

irrigation water under basin irrigation (51-167 l/day/plant) than drip

irrigation (36-131 l/day/plant) during various stages of crop

development.

3.2.1.4 Papaya

Adoption of drip irrigation resulted in water savings of 25-45%

in papaya compared to surface basin irrigation (Padmakumari &

Sivanappan, 1983). Srinivas (1996) registered a 50-60 % of water

39

saving with drip method than furrow irrigation (3510 mm) in papaya

at Bangalore. Sivanappan (1998) found 68% savings in water at

Coimbatore with adoption of drip irrigation compared to basin

irrigation (2280 mm).

3.2.1.5 Pomegranate

Adoption of drip irrigation in pomegranate resulted in a water

saving of 45 to 94% at various locations in India over basin irrigation

method. Sivanappan (1994) reported 45 % of water saving in

pomegranate with drip than conventional basin irrigation at

Coimbatore (1440 mm). On the other hand the work of Singh et al.

(1993) registered 35-50% of water savings in pomegranate with drip

irrigation as compared to basin method at Pantnagar. Where as Magar

(1985) reported water savings of 62% in Maharastra with drip

irrigation than basin irrigation (1080 mm). At Bilaspur substantial

water savings of 94% were registered by adopting drip irrigation in

pomegranate compared to basin irrigation (WMS 1997).

3.2.1.6 Other crops

In grapes Umesh Chander et al. (1981) recorded a water savings

of 48% at UAS, Dharwad with drip irrigation compared to flood

irrigation (5320 mm). Alam (1987) reported water saving of 59 % in

grapes compared flood method of irrigation. Bendale et al. (1998)

stated that the water use with drip irrigation was 25% less compared

with furrow irrigation in Sangli region of Maharastra. On the other

40

hand Srinivas (2001) reported water saving of 32% in grapes with drip

irrigation over flood irrigation at Bangalore. Similarly

Narayanamoorthy (2004) reported a water saving of 37% in grapes

from Maharastra.

3.2.2 Vegetables

The adoption of drip irrigation resulted in a water savings which

varied from 6 to 84% in different vegetables under different agro-

climatic conditions of India. (Raman et al., 2001)

3.2.2.1 Tomato

Adoption of drip irrigation in tomato contributed to 6 to 79%

savings in water. The work of Sivanappan and Natarajan (1976) on

drip irrigated tomato revealed a water savings of 79% over flood

irrigation at Coimbatore. On the other hand Asokaraja (1998) reported

marginal water savings of only 6% in Tamilnadu compared to surface

furrow irrigation (421 mm).

Pandey and Vijay Mahajan (1998) studied the comparative

performance of drip and surface methods of irrigation in tomato (var.

Pusa early dwarf) and stated that there is a water savings of 20-52 %

over surface method of irrigation. Like wise Raina et al. (1998)

reported a water saving of 54% in tomato with drip irrigation. Similar

water savings with drip irrigation were reported by up to 30%, (297

mm) under furrow irrigation (Anonymous,1984) at Rahuri, 39% of

water savings by Singh et al. (1993) at Pantnagar, 35% water savings

at Gujarat by Raman et al. (2001), 14% water savings at Pantnagar by

41

Chauhan (2001), 21% of water savings in Maharastra by Magar

(1985) and 50% by Prabhakar and Hebber (1996) at UAS, Dharwad

over furrow irrigation.

3.2.2.2 Brinjal

Sivanappan and Natrajan (1976) conducted experiments in

brinjal and found a water saving of 65% than furrow irrigation method

(692 mm). Like wise Tefera (1987) reported a saving of 41.28% of

water with drip irrigation compared to surface furrow irrigation at

Pantnagar, while Singh et al. (1993) registered water savings of 56%

over surface furrow irrigation at Pantnagar.

Chauhan (2001) recorded water saving of 29 to 41.28% in

brinjal at Maharastra. Raman et al. (2001) found water savings of 64%

with drip irrigation in brinjal at Navsari, Pantnagar compared to

furrow irrigation (690 mm). The research studies conducted at PDKV,

Akola revealed water savings of 62% in brinjal over furrow irrigation

(1680 mm).

3.2.2.3 Chillies

Adoption of drip irrigation in chillies recorded water savings

varied from 23 to 62% at different agro-climatic conditions. The

research carried out at AICRP, Navsari revealed water saving of 23%

with drip irrigation compared to flood irrigation (1200 mm). (NCPA

1990). Singh et al. (1993) recorded 62% of water saving at Pantnagar,

while Manjunatha et al. (2001) reported 40% of water savings. On the

42

other hand Chauhan (2001) found 67% water saving at Pantnagar

with drip in chillies.

3.2.2.4 Other vegetables

Sivanappan and Padmakumari (1980) reported water saving of

83% in bhendi, 76% in radish, 79% in beet root, 60% in sweet potato

with drip irrigation compared to furrow irrigation.

Ravi Babu et al. (1995) estimated the water savings with

different microirrigation systems in bhendi and found drip irrigation

with single micro tube resulted in water savings of 47.71% over furrow

irrigation. The studies carried out by Bhatia et al. (2001) at CAZRI,

Jodhpur , revealed that the drip irrigation contributed to a water

saving of 35-50% in long gourd, round gourd, watermelon, potato,

cole crops, and maize.

3.2.3 Sugarcane

Adoption of drip irrigation resulted in water savings of 32 to

75% in sugarcane. Sivanappan and Padmakumari (1980) reported

32% of water savings in sugarcane at Coimbatore with drip irrigation

compared to flood irrigation (1360 mm). Shinde et al. (1998) recorded

50% of water savings with drip irrigation compared to furrow

irrigation (2206 mm) at Pune. On the other hand Narayanamoorthy

(2004) observed water saving of 40 to 47% in sugarcane cultivated

with drip irrigation compared to flood irrigation in Maharastra. Singh

et al. (1993) recorded water savings of 56% in drip irrigated sugarcane

at Pantnagar as compared to furrow irrigation (2150 mm).

43

3.3 IMPACT OF SURFACE DRIP IRRIGATION ON POWER

SAVINGS

Electricity savings is one of the important advantages of drip

method of irrigation. Drip irrigation substantially reduces the working

hours of pumpset by reducing the water consumption. As a result,

electricity required for irrigating unit area of land also reduces

significantly (Narayanamoorthy, 2004).

Narayanamoorthy, (1996, 1997 & 2001a) reported that the

adoption of drip irrigation resulted in a power savings of 44% in

sugarcane 37% in grapes and 29% in banana over flood irrigation in

Maharastra. Similarly the field survey conducted by

Narayanamoorthy, 2004 revealed a power saving of 41% in sugarcane

at Pune and 48% at Ahmednagar.

3.4 IMPACT OF SURFACE DRIP ON FERTILIZER SAVINGS

The right combination of water and nutrients is the key for high

yield and the quality of produce. Fertigation (application of fertilizer

solution with drip irrigation) has the potential to ensure that the right

combination of water and nutrients is available at the root zone,

satisfying the plants total and temporal requirement of these two

inputs (Neelam Patel and Rajput, 2001).

Fertigation in addition to saving of fertilizers also permits

applying fertilizer in small quantities according to the plants nutrient

requirements.( Veeranna et al., 2001 and Bhoi et al., 2001). It is also

44

considered eco-friendly as it avoids leaching of fertilizers.

(Shivashankar et al., 1998).

Adoption of drip fertigation resulted in savings of fertilizers over

surface broadcasting viz., 20% in banana, 50% in sugarcane, 40% in

bhendi, 40% in tomato, and 40% in onion. (Task Force Report, 2004).

Similarly Neelam Patel and Rajput (2001) reported fertilizer savings of

40% fertilizers as compared to the broadcasting method of fertilizer

application without affecting the crop yield in bhendi.

Anil kumar singh et al. (2001) reported 20-40% fertilizer savings

in Broccoli on sandy loam soil through fertigation compared to

traditional application.

Neelam Patel and Rajput, (2001) reported 60% fertilizer savings

in onion at IARI, New Delhi with fertigation compared to broadcasting.

3.5 IMPACT OF SURFACE DRIP IRRIGATION ON BENEFIT COST

ANALYSIS

Drip irrigation method requires fixed capital for installing the

drip system and the magnitude of the investment varied from crop to

crop. Wide spaced crops require relatively low fixed capital, while the

narrow spaced crops require higher fixed capital (NABARD, 1989).

Though the initial investment on drip system was high, due to its

results in increased yields, water savings and reduced cost of

cultivation result in a highest benefit cost ratio (Sivanappan, 1998);

Narayanamoorthy (1997 & 2004).

45

3.5.1 Fruits

Sivanappan, (1998) reported a benefit cost ratio of 3.00 in

banana at Maharastra compared to 2.35 in flood irrigation. Tiwari

(1997) studied the response of banana under different irrigation

regimes of drip irrigation and found the highest gross benefit ratio of

4.56 with drip irrigation than basin irrigation, where as Pawar et al.

(2001) studied different irrigation and fertigation schedule and

reported that the benefit cost ratio was 2.72 under surface method

compared to 2.64 with drip irrigation at Rahuri in banana.

In sweet orange Rajbir singh et al. (2001) evaluated the

performance of drip irrigated Kinnow crop in Punjab and found a

benefit cost ratio of 2.36 with drip irrigation compared to 1.39 under

surface irrigation. Similarly Sivanappan (1988) reported a benefit cost

ratio of 1:2.60 with flood and drip irrigation in sweet orange at

Maharastra and Tamilnadu.

The studies conducted by Sivanappan (1988) revealed that a

benefit cost ratio of 1:1.52 in banana, 1:1.35 in mango, 1:1.54 in

papaya, 1:1.56 in pomegranate with the adoption of drip irrigation

over surface irrigation. Narayanamoorthy (1997) reported a benefit

cost ratio of 1:2.16 in banana and 1:1.76 in grape with drip irrigation

compared to flood irrigation.

3.5.2 Vegetables

Sivanappan, (1988) reported a benefit cost ratio of 1:2.80 in

chillies, 1:1.80 in tomato, 1:1.89 in brinjal at Tamilnadu with drip

46

irrigation compared to furrow irrigation. Likewise Manjunatha et al.

(2001) reported a benefit cost ratio of 1:11.91 in brinjal at ARS,

Gangavathi with drip irrigation over furrow irrigation.

3.5.3 Sugarcane

Sivanappan, (1988) reported a benefit cost ratio of 1:3.45 in

sugarcane in Tamilnadu. On the other hand Narayanamoorthy,

(2001 b) reported 1:2.02 with 10% discount rate with out subsidy with

the adoption of drip irrigation over flood irrigation in Pune and 1:1.87

in Ahmednagar in sugarcane.

3.6 IMPACT OF SURFACE DRIP ON SOIL SALINITY AND NO3

LEVELS

Drip fertigation provides an efficient method of fertilizer delivery

and allows precise timing and uniform distribution of applied

nutrients. Fertilizer application through drip irrigation (fertigation) can

reduce fertilizer usage and minimize groundwater pollution due to less

fertilizer leaching from irrigation. (Badr and Abou 2007).

Dariusz Swietlik (1995) reported that the nitrate leaching was

less with low volume irrigation compare to flood irrigation in grape

fruit orchard cv. 'Ray Ruby'.

Ramakrishna (2003) reported that properly designed trickle

irrigation system has the ability to minimize the salt concentration of

the soil water in the vicinity of plant roots, salt movement and hence

salt distribution in soils is directly related to water movement.

Adoption of drip irrigation resulted in concentration of salts at 0-50

47

cm depth and it reduces with the increase in depth. The fertilizer

application through fertigation device is restricted to the wetted

volume of soil where the active roots were concentrate and hence was

available to plants fully ( Neelam Patel and Rajput ,2001).

Mirjat et al. (2008) studied the nitrate movement in the soil

profile at Tanndojam, Pakistan and reported that the NO3- N

concentration was concentrated only in the top 0.6m depth under

trickle and sprinkler irrigation methods due to insignificant water

movement towards deeper depths, whereas under basin and furrow

irrigation methods the NO3 moved along with water deep into the

profile. Further the NO3 values were below threshold levels under drip

and sprinkler methods as compared to flood irrigation.

3.7 IMPACT OF SURFACE DRIP ON GROUND WATER NO3 LEVELS

Of all the fertilizers applied to the soil for increasing crop

production, nitrogenous ones are the most important. These are

rapidly converted in arable soils to NO3 form, which are readily

available to plants, but are highly soluble and hence easily leachable.

When quantity of nitrogen added to the soil exceeds the amount that

the plants can use, the excess NO3 does not get much adsorbed by soil

particles, but leaches out from the root zone by percolating water

through the soil profile and ultimately accumulates into the

groundwater. The magnitude of such leaching, however, depends

upon soil characteristics, types of crop grown, and management

practices followed. (Kundu et al., 2008).

48

Nitrate leaching is a global problem. Recently, there have been

many studies in India which point to the danger of nitrate leaching

and subsequent pollution of ground waters. Due to increased

agricultural activity which is necessary for enhanced food production

and also due to industrial activity, there is an increasing evidence of

nitrate pollution of ground waters. In agriculturally intensive areas of

Punjab, Delhi, Maharashtra and Andhra Pradesh where fertilizer

application levels are high, there is ample evidence of pollution of

ground waters by nitrate (Prakasa Rao & Puttanna, 2000).

Kundu et al. (2008) reported that the nitrate content was

significantly higher in samples collected during the post monsoon

season (0.87mg/l) than in those of premonsoon (0.58 mg/l) in

groundwater in Hooghly district where there is a usage of higher rate

of N-fertilizer.

Ritter and Manger (1985) concluded from the literature that

nitrate movement below the crop root zone can be minimized by

adopting proper water application methods. Linderman et al. (1976)

found that the quality of water percolating below a furrow irrigated

sandy soil varied from 25 to 30 mg/l NO3 depending on the nitrogen

application practices. Likewise Bouwer (1987) found that the nitrate

in the soil water solution moving below the crop root zone ranged from

15 to 50 mg/l. Keeney (1982) suggested that with the use of best

management practices the nitrate level in the soil water solution could

be reduced.

49

The work of Watts and Martin (1981) revealed that the content

of nitrate movement below the crop root zone is dependent on the

quantity of percolating water, thus the average NO3 – N losses were

19, 30, and 60 Kg/ha/year when deep percolation was 1.6, 2.9, and

7.3 cm/year, respectively (Smika et al.,1977).

50