Towards adopting nanotechnology in irrigation: Micro irrigation systems
Excessive and unbalanced use of water is a common practice to grow more; to earn more. Micro Irrigation System helps reduce water loss occurring through evaporation, conveyance and distribution.

India is predominantly an agricultural country and even with current orientation towards services, still agriculture contributes ¼th of total GDP of the country, 15 percent of total export and 65 % of total population’s livelihood. After independence, India has made remarkable progress in increasing food production and productivity, credit goes to concerted efforts made under various Agri revolutions. For agriculture Land and Water are two most important resources. Of which, water (irrigation) becomes lifeline of agriculture. It is a truth in agriculture “if we fail in irrigation, we will fail in agriculture”.

Water is required for agriculture as well as for other sectors (Domestic, Industries, etc) and the demand of water is increasing alarmingly. At present level, agriculture consumes over 80 per cent of total water consumption in India. The country is endowed with many perennial and seasonal rivers. The river system which constitute 71 per cent of water resources is concentrated in 36 % of geographic area. Most of agricultural fields are irrigated by use of underground water for assured irrigation, however, erratic, mansoon based rainfall is source for water for rainfed agriculture. Though water is a renewable resource, the recharge is ultimately limited to rain. Drought like situation in Indian agriculture is more common and occurs frequently in some of the part of vast geography of the country almost every year. Excessive and unbalanced use of water became a common practice to grow more & more to earn more & more. In other words, the water resources are being depleted by current practice of farming and we will be devoid of sufficient irrigation water if the trend continues in years to come. All these factors are focusing the need of judicious and efficient use of water for agricultural use.

Various type of flood method of irrigation is commonly and traditionally followed in almost whole India. This system offers liable to loss of water conveyance, distribution and evaporation. Therefore, about 30-40 % of applied water is being utilized by the crop rest is leached out; evaporated, or lost through surface run off.

The ground water level has reached to the alarming level ue to ever increasing demand of use of Ground water for irrigation. National-wide study has reveled that most of irrigation area in India are due to use of ground water. In states of Punjab, Rajasthat, Haryana, Gujarat, Andhra Pradesh, Karnataka, Tamil Nadu, etc, the level of ground water has reached to the extent of Over Exploited, Semi Critical to Critical level. 

Micro Irrigation System is panacea in irrigation related problems. In this technology, field is irrigated in the close vicinity of root zone of crop. It reduces water loss occurring through evaporation, conveyance and distribution. Therefore high water use efficiency can be achieved (Table 1). The unirrigated rainfed cropped area, could be irrigated with the water saved with this technology become a potential source of food production for the benefit of country’s food security.

 Table 1: Irrigation efficiency under different methods of irrigation

 

Irrigation efficiencies

Methods of Irrigation

Surface

Sprinkler

Drip

Conveyance efficiency

40-50 (canal)

60-70 (well)

100

100

Application efficiency

60-70

70-80

90

Surface water moisture evaporation

30-40

30-40

20-25

Overall efficiency

30-45

50-60

80-90

Micro-irrigation system is the best available way to utilize water and fertilizer efficiently under farm conditions. The type of Microirrigation system may very with the type of crop selected and amount of water available for irrigation (Table 2). However, modern technology was developed in Israel. Since MIS is a well planned and scientifically designed way of farming, it also provides option for Crop diversification. Unlike surface irrigation, drip irrigation is more suitable and economical if it is introduced in water scarce areas having undulated topography, shallow and sandy soils barren and for wide spaced high value crops. It reduces cost of cultivation, increases productivity and reduces energy (electricity) consumption.

 Table 2: Crop group wise advisable Micro Irrigation System

Crop group wise advisable Micro Irrigation System

Crop

Crop Spacing

Adjustable Micro Irrigation System

Horticulture Crop

12 m to 3 m between crop raw. (wide spaced)

Drip Irrigation System / Pours Pipe

Crops fruit part under ground like Potato, Groundnut, Turmeric, Ginger, Vegetables, Medicinal Crops etc.

Less then 1 m between crop raw. (Narrow)

Drip Irrigation / Sprinkler Irrigation / Raingun

Field Crops like Cotton, Castor, Tobacco, Pulses, Sugarcane, Banana, Vegetables etc.

Less then 3 m between two crops

Drip Irrigation

Fodder Crops / Nursery Raising of Vegetables, Ornamental Crops etc.

-

Sprinkler Irrigation / Raingun

 The advantages of drip irrigation are:

  • Minimized fertilizer/nutrient loss due to localized application and reduced leaching.
  • High water application efficiency.
  • Leveling of the field not necessary.
  • Ability to irrigate irregular shaped fields.
  • Allows safe use of recycled water.
  • Moisture within the root zone can be maintained at field capacity.
  • Soil type plays less important role in frequency of irrigation.
  • Minimized soil erosion.
  • Highly uniform distribution of water i.e., controlled by output of each nozzle.
  • Lower labour cost.
  • Variation in supply can be regulated by regulating the valves and drippers.
  • Fertigation can easily be included with minimal waste of fertilizers.
  • Foliage remains dry thus reducing the risk of disease.
  • Usually operated at lower pressure than other types of pressurised irrigation, reducing energy costs.

Crop-wise water saving over surface irrigation method and increase in yield is presented in table (Table 3).

 Table 3: Crop-wise water saving and increase in yield

Crop

yield (q/ha)

Irrigation

Surface

Drip

% Increase

Surface

Drip

% Saving

Beet root

5.7

8.8

54

86

18

79

Bitter gourd

32

43

34

76

33

57

Brinjal

91

148

63

168

64

62

Brocolli

140

195

39

70

60

14

Chilli

171

274

60

27

18

33

Cucumber

42.3

60.9

44

109

41.7

62

Okra

155

225

45

54

24

56

Onion

284

342

20

52

26

50

Potato

172

291

69

60

27.5

54

Radish

10.5

11.9

13

46

11

76

Sweet potato

42.4

58.9

39

63

25

60

Tomato

61.8

88.7

44

49.8

10.7

79

Banana

575

875

52

176

97

45

Grapes

264

325

23

53

28

47

Papaya

130

230

77

228

73

68

Pomegranate

34

67

97

21

16

24

Watermelon

82.1

504

514

72

25

65

Even having many benefits the reach of MIS among the farmers restricted. Though, the government is trying to promote the technology through part financial support to offset its high initial cost syndrome. Few adoptions were observed in the decade of eighties and nineties (Table 4). Putting all together efforts of all machineries under one, total coverage of land under MIS is less than 1 per cent, which underlines the need of integrated efforts to be made by all stake holders. The rural electrification is another major constraint for the popularization of drip systems among farmers. The high care as well as meager crop and soil specific technology are few major constraints for deeper reach of the technology among farmers.

Table 4 : Decade wise development in the field of Micro-irrigation

Decade

Focus of Research/ extension

Seventies

Comparisons of micro irrigation system with conventional systems in terms of water savings and yield enhancements.

Eighties

Estimate water requirements, modifications of crop geometry and use of mulches in drip irrigated fields for realizing the potential benefits of the system

Nineties

Develop hardware and software for cost reduction, design modifications and fertigation and chemigation

Twenty first century

Precision farming, including the use and application of software and more efficient instruments in agriculture besides the use of simulation and modeling of moisture and nutrients movement under different soil and dripper characteristics 

Promotion of adoption of Micro Irrigation System in India

  1. Concerted efforts taken by the Government / NGO and the MIS companies for widespread awareness about the usefulness of the wonderful technology.
  2. Efforts should be made to ensure the production and supply of good quality microirrigation system to the farmers by enforcing strict quality control measures.
  3. Microirrigation should be made an integral part of all irrigation projects.
  4. The microirrigation system manufacturers should also guide the farmers in adopting suitable agronomic practices along with microirrigation.
  5. After sales service should be strengthen. 
  6. Technological intervention is required to cut down the cost of Micro-irrigation system.

 

Dr. Sarvesh Kumar Shah
H-12, Komal Enclave, Shantivan, Paldi, Ahmedabad-380 007
sarveshshah@gmail.com

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