Micro irrigation for Electricity Saving in Gujarat-A Potentiality Assessment Dr. S.Raman, Advisor, Gujarat Green Revolution Company, Vadodara The Gujarat state is situated on the western part of India. It is surrounded by Arabian sea in the West, state of Rajas than in the North East, international boundary with Pakistan on the North, Madhya Pradesh in the East and Maharashtra in the South East and South. It has the longest sea coast in India with a length of about 1600 Km.It is located between 20 0 01 ' and 24 0 07 ' North latitudes and 68 0 04 ' and74 0 04 ' East longitudes. It covers an area of 19.6Mha (1.958 lakhs Km 2 ) contributing to 6 per cent of the total geographical area(tga) of the country. The state had 19 districts earlier, which subsequently has been divided to 25 during 1998 and 26 during 2007. The population of the state according to 2001 Census is 50.67 million accounting nearly 5% of the country. The density of population is 2.58 persons per sq.km. and it is lower than all India figure of 324 persons. Urban population accounts for 37.36 percent as against 27.78 percent for the country and ranks 5 th among the states of India. Gujarat is endowed with many rivers some of which are perennial while many are seasonal. The perennial large rivers like Narmada, Tapi, Mahi and small ones like DamanGanga are flowing in the South and middle Gujarat. On the other hand in North Gujarat the rivers are not only very few but also seasonal in flow. Sabarmati, Banas, Rupen and Saraswati are the important ones. Sector wise Water Demand During the year 2000, the total water requirement was estimated to be around 29.4 thousand MCM and it is estimated to rise to 36.5 thousand MCM during 2010 and 46.8 thousand MCM during 2020 and 53.1 thousand MCM during 2025 registering an increase of 80 per cent ( table 1). At the state level the maximum contribution for the per cent increase is from industry which is estimated to draw 736 per cent more water than as on 2000. This is followed by the demand for domestic use with a percentage increase of 165. Table 1: Trend of Water Requirements by Different Sectors Sector Water Requirement(MCM) 1997 2000 2010 2020 2025 Domestic 1374 1545 2288 3618 4103
(165) Industrial 448 644 1505 3522 5386 (736) Livestock 224 230 239 263 284 (23) Agriculture 25672 27013 325151 39352 43306 (60) Total 27616 29431 36558 46769 53088 (80) Source : White paper on Water, IRMA 2000 ( ) Variation over 2000 in % The water requirement for agriculture which was 93 during 2000 will be going down steadily and it will contribute to 80 per cent of the total water requirement by 2025. This reduction is mainly due to the more percentage demand by other sectors and not due to reduction in the quantity of water required in this sector. In fact by 2025 the state needs 16 thousand MCM more of water for agriculture. Status Out of the 124 lakh hectares of culturable area, the gross irrigated area in the state as reported for the year 98-99 was 38.4 lakh hectares working out to a percentage of 31. The corresponding net irrigated area was 30.8 lakh hectares with a percentage of 24.8. Tank Canal Tube well Other wells Others Total Net Gros s Net Gros s Net Gross Net Gross Net Gros s Net Gross Gujara t 25 3 305 602 1 7109 889 7 1113 3 1542 8 1955 3 24 5 306 3082 4 3840 6 Source : Irrig.dept Download from web site The area under gross canal irrigated area with a hectaerage of 7 lakhs contributes to 18 per cent of the gross irrigated area in the state leaving around 82 per cent as ground water irrigated area. The tank command in the state is less than 1 per cent. Ground Water Status and Use
Presently, the ground water, contributes to 80 per cent of the irrigated area in spite of its low potential (16,000MCM as against 39,000MCM of surface water potential). While in South and middle Gujarat, surface water is the major source of irrigation, in the North Gujarat, Saurashtra and Kutch regions, the ground water contribution as source of irrigation water is more than 90 per cent. The total number of groundwater extraction structures are 6.6 lakhs of which 5.06 lakhs are electrified and 1.54 lakhs are diesel pump sets(table) Table 9: Districtwise Water Extraction Structures for District Electrified sets Diesel Sets Total Ahmedabad 6656 4736 11393 Amreli 24930 16965 41895 Anand 8060 715 8775 Banaskantha 48066 5950 54016 Bharuch 5735 235 5970 Bhavnagar 28978 13351 42329 Dangs 136 320 456 Dohad 3918 12341 16259 Gandhinagar 8494 15 8509 Jamnagar 35614 9774 45388 Junagadh 57002 23483 80485 Kutch 13477 6727 20204 Kheda 13438 2630 16068 Mahesana 18439 1172 19611 Narmada 2191 423 2614 Navsari 16812 75 16887 Panchmahals 15296 10675 25971 Patan 4299 0 4299 Porbandar 8303 3353 11656 Rajkot 49890 20096 69986 Sabarkantha 65013 6158 71171 Surat 29511 225 29370 Surendranagar 18597 7650 26247 Vadodara 13845 7186 21031 Valsad 9648 380 10028 Total 506348 154636 660482 Source : GWRE, Narmada and Water Resources, GOG 2002
As per 2002 figures, the annual ground water recharge in the state is 18000 MCM per year of which 14400 MCM is calculated as utilizable recharge. The gross ground water draft is estimated to be 11400MCM leaving a ground water balance as 3000 MCM. Thus, with the over all development of about 80 %, the state falls under the Grey category. During 1984, the state was under White category. Though, at the state level it is under Grey category there is lot of inter districts variations. While, the South Gujarat districts are still falling under White category, majority of the North Gujarat districts are falling under Over Exploited category. During 1984, 95 per cent of the talukas were under White and Grey categories and rest 5 per cent were either Dark or Over Exploited or Saline. But, during 2002, only 74 per cent of the talukas were falling under either White or Grey category. As high as 19 per cent of the talukas fall under Over Exploited category and 5 per cent of the talukas exhibit complete Saline water conditions. As a result of the excess draft conditions, especially in North Gujarat, the water table is receding at a very fast rate. of 5-6 meter per year. During 1960s and 1970s the depth of the tube wells in North Gujarat ranged between 80 and 120 meters. But, of late, the tube wells have to be drilled to a depth of even more than 300 meters. This tube well deepening trend had necessitated the farmers to go in for lifting devices with very high HP. Apart from receding water table, the mining of ground water as is being done in North Gujarat has resulted in water pollution with special reference to Fluoride. It is reported that at least 15 per cent of wells in the state are exhibiting high fluoride content. In North Gujarat, every third well is having fluoride problem and in Mehsana district of North Gujarat, every alternate well is fluoride polluted. The over draft of ground water has also resulted in intrusion of seawater especially in the coastal areas of Saurashtra and Kutch. Improvement in irrigation efficiency will go a long way to reduce the over draft. The first step in increasing the use efficiency of irrigation water is the selection of proper irrigation method. Different methods are used to apply irrigation water to the crop depending upon the source of supply of water, topography, quantity of water to be applied, crop and planting/sowing method of the crop etc. PRESSURIZED IRRIGATION METHODS: The surface irrigation methods like basin, border strip, furrow etc., which are conventional ones, have many drawbacks of which, the poor irrigation and water use efficiencies are most important.
Controlled irrigation like drip and sprinkler can overcome above said drawbacks considerably. The poor water use efficiency in surface methods as compared to the pressurized systems is mainly due to wetting and drying cycle (see figure) that is met by the plants grown under surface irrigation in comparison to the drip. Drip irrigation Drip irrigation is a method of irrigation wherein water is carried to the plant under low pressure; through small diameter plastic pipes and delivered at the root zone, drop by drop through an emitting device. This is based on the fundamental concept of irrigating only the root zone of the crop rather than the entire land surface, as done in the surface irrigation. It is most suited for horticulture crops, vegetables etc. and finds applicability in hard rock areas where groundwater is scarce and helps in optimization of the limited water resources. The system has its advantages and limitations. Its advantages are in terms of savings of water over flow irrigation, effective use of fertilizers, less labour and energy cost. The limitation for adopting of this method is its high initial cost, which is beyond the purchasing capacity of small and marginal farmers and thus mainly adopted by large farmers. The concept of this method of irrigation is not new to our country. In India, the concept of micro irrigation was originally practiced through some indigenous methods like bamboo pipes irrigation in Meghalaya, perforated clay pipes and pitchers in Maharashtra and Rajasthan. Drip irrigation is essential because: Water resource management is very crucial for India and this can be best done through the micro irrigation technology. The per capita water availability is rapidly getting reduced.
More emphasis on horticultural development. Problems of water logging and secondary salinization on the rise in canal command areas and fast receding water table in the tube well commands. Increase in the ground water pollution levels Deteriorating status of input use efficiencies (particularly water and fertilizer) Advantages of Drip over Conventional Method Parameter Conventional Method Micro Method Water saving Waste lot of water. Losses occur due to percolation, runoff and evaporation 40-70% of water can be saved over conventional irrigation methods. Runoff and deep percolation loses are nil or negligible. Crop yield Full yield potentiality is not achieved due to wetting and drying cycles and improper air : water ratio Tendency for increase in the yield due to proper air: water ratio in the soil and better nutrient availability in the soils Water use efficiency 30-50%, because losses are very 80-95% high Saving in labour Labour engaged per irrigation is higher than drip Labour required only for operation and periodic maintenance of the system Power savings More power requirement due to Less power requirement. more hours of pumping for irrigating unit area Reduced weed Intensity Weed infestation is very high Less wetting of soil, weed infestation is very less or almost nil. Environmental impact Due to misuse, problems of either water logging coupled with secondary salinisation in the canal command and receding water table in the ground water command area No water logging problems No receding water table No ground water pollution
are on the rise. In addition, the danger of ground water getting polluted is more Use of saline water Concentration of salts increases and adversely affects the plant growth. Saline water can not be used for irrigation Frequent irrigation keeps the salt concentration within root zone soil below harmful level. Better scope of use of saline water Diseases and pest problems High Relatively less because of less atmospheric humidity Suitability in different soil types. Deep percolation is more in light soil and with limited soil depths. Suitable for all soil types as flow rate can be controlled. Runoff loss is more in heavy soils. Soil irrigabilty class Main constraint Poor irrigable class soil also can be irrigated easily Water control Inadequate Very precise and easy Efficiency of fertilizer use Soil erosion Efficiency is low because of heavy losses due to leaching and runoff Soil erosion is high because of large stream sizes used for irrigation. Very high due to reduced loss of nutrients through leaching and runoff water. 30to40% fertilizer can be saved (table ) Partial wetting of soil surface and slow application rates eliminate any possibility of soil erosion Constraints 1. Initial investment costs per hectare may be higher than for other forms of irrigation. 2. Management requirements and skills are higher. 3. Drip irrigation is not adaptable for frost protection. 4. Rodent, insect, and human labor may cause damage to components and create potential sources of leaks.
5. When compared with sprinkler irrigation, water distribution in the soil is limited. Distribution of moisture should be a major design consideration. 6. Water filtration is a must. Clean water is necessary to prevent clogging of the small emission holes found in this system. 7. Drip irrigation is not advisable for closely planted crops such as alfalfa or cereal grains. Water Savings with DIS Crop Water Use(mm) Conventional Drip %Water Saving Banana 1760 970 45 Grapes 532 278 48 Sweet lime 1660 640 61 Pomegranate 1440 785 45 Papaya 228 74 68 Tomato 300 184 39 Water Melon 330 210 36 Okra 54 32 40 Cabbage 66 27 60 Chilies 110 42 62 Sweet Potato 63 25 60 Beetroot 86 18 79 Radish 46 11 77 Sugarcane 2150 940 56 Cotton 60 30 50 Electricity Consumption Trend: As per the available data, during 2001, out of the total supply of electricity in the state for various sectors, 49 per cent was consumed by agricultural sector alone. But the revenue generated as income to the GEB by this sector was only 4 per cent of the total.
Among the different regions of the state, the agriculture sector in North Gujarat alone consumes 23 per cent of the total power consumed in the state. Any small saving in electricity in this sector will go a long way in Getting more return per unit power generated Reducing staggering for other sectors Reducing the need for power generation as power saved will be power generated. Thus, there will not be need to generate additional power to the extent of power saved. Regionwise and Sectorwise Electricity Consumption. Region Consumption in MUs % use of Total GEB Supply Agriculture Other Use in % S. & Central 2725 12350 18 9 Kutchh 1189 1603 43 4 Saurashtra 4295 7323 37 14 North Gujarat 7259 10275 41 23 SSSource: Mehul Patel, Personal communication Districtwise and Sectorwise Electricity Consumption in North Gujarat Consumption in MUs Distt Agriculture Other Use in % % use of Total GEB Supply Palanpur 2793 3125 89 9 Mehsana 2424 3680 66 8
Sabarmati 1115 2277 49 3 Himmatnagar 917 1193 76 3 TOTAL 7249 10275 23 Source; Mehul Patel, Personal communication Adoption of drip irrigation to a great extent can effectively save power due to less water use and there by reduction in the time of operating of the pump. The power saving vary according to different micro irrigation systems and crop types and their geometry. For wide spaced orchard crop group the electricity savings with drip irrigation has been estimated to be around 278 kwhr/ha and it will be about 100 kwhr/hr for close grown crops under drip T Potential Savings in Electricity consumption in different crops due to Micro S. No. Crop Average annual irrigation depth, mm Average annual Energy Requirement, kwhr/ha Flood Drip/Spr. Flood Drip/Spr Saving [1] [2] [3] [4] [5] [6] 1 2 Widely Spaced for Drip Closely Spaced for Drip [7] = [5]-[6] 900 600 1667 1389 278 1700 1200 3148 2778 370 3 for Sprinkler 500 350 926 810 116 Source: Task Force Report,MOA,GOI For close grown crops under sprinkler irrigation it may be around 120 kwhr/ha only. There are some recent systems like porous pipe which works on the principle of suction irrigation requiring very low head. Hence this system will result in more electrical power saving. Flood Low Flow Porous Pipe SSI Low Flow / Low Pressu re Drip / Sprinklers Rain gun / Sprinklers High Flow / High Pressure system
system Pressure requirement for different MIS GL 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 kg/cm² Pressure requirement for different MIS Bar 5 10 15 20 25 30 35 40 45 50 (Mts.) Total Head in Mts. 30 35 40 45 50 55 60 65 70 75 80 hrs. / day 8 8 8 8 8 8 8 8 8 8 8 Total Water delivery( 000L/ day) Water Req./ Day / Hct. ( 000L) Energy consumption in kw / hr for Irrigating same area as Porous Pipe SSI 547 469 411 365 328 299 274 253 235 219 205 100 42.5 50 50 50 50 50 50 50 50 500 120 60 80 90 100 110 120 130 140 150 160 Source: Mehul Patel, Personal Communication Based on the Savings in Electricity consumption explained under Tables 3 and 4, and based on the yearly targeted areas of adoption of micro irrigation presented in Table-1, the yearly potential savings in Electrical power that can be saved with the help of micro irrigation have been calculated by the Task Force appointed by the GOI and presented under Table 7.5, which indicate that the value of electricity saved through micro irrigation would be of the order of Rs. 3767 crores between 2004-05 and 20011-12. Table 7.5: Saving in Subsidized Electricity supplied to Agriculture Sector due to Adoption of microirrigation in India S.No Year 1 2004-05 2 2005-06 3 2006-07 Proposed area for adoption, million ha Widely Spaced for Drip Closely Spaced for Drip for Sprinkler 0.190 0.310 0.250 0.75 0.260 0.440 0.350 1.05 0.300 0.500 0.400 1.20 Cost of Electrical Power Saved ( Rs Crores ) Total Widely Spaced for Drip Closely Spaced for Drip for Sprinkler Total Widely Spaced for Drip Cumulative Cost of Electrical Power Saved( Rs Crores ) Closely Spaced for Drip for Sprinkler Total 13 29 7 49 13 29 7 49 18 41 10 69 31 69 17 118 21 46 12 79 52 116 29 197
4 2007-0.370 0.630 0.600 1.60 08 26 58 17 101 78 174 46 298 5 2008-0.550 0.950 0.700 2.20 09 38 88 20 146 116 262 67 445 6 2009-0.740 1.260 0.800 2.80 10 51 117 23 191 167 378 90 636 7 2010-0.930 1.570 0.900 3.40 11 65 145 26 236 232 524 116 872 8 2011-1.110 1.890 1.000 4.00 12 77 175 29 281 309 698 145 1153 Total 4.450 7.550 5.000 17.00 309 698 145 1153 999 2250 518 3767 Assumption: Production cost of Electricity is assumed as Rs 2.50/kWhr. Source : Task Force Report, MOA,GOI After the inception of the Gujarat Green Revolution Company which is the nodal agency for implementation of all the schemes on micro irrigation in Gujarat, there has been a phenomenon increase in the adoption of micro irrigation in the state. Between 2005-06 and 2008-09 as many as 1.3 lakhs hectares have been brought under this modern method of irrigation. Though this system is being used for irrigating more than 40 different crops, yet the major crops are cotton, groundnut, wheat, banana, sugarcane, potato and mango. These crops together contribute to 80-85 per cent of the crops under micro irrigation in the state. The power savings in these crops due to drip has been estimated to be as below. CROP KWHr/ha BANANA 1660 COTTON 258 SUGARCANE 1250 MANGO 371 OTHER ORCHARDS 313 OTHER CROPS 200 The sprinkler irrigated crops have been found not to contribute much in terms of power savings.
Case Study 2006-07 During 2006-07, micro irrigation has been installed in an area of about 27000ha. Considering the hectaerage under different crops with drip irrigation, installed during 2006-07, Estimated Savings Energy Requirement (LkWhr) Total 141 27.3 27.3 49.6 8.6 28.0 Cotton Banana Sugarcane Mango Others it is estimated that totally 141 L KWhr energy would have been saved that year due to adoption of the MIS. Sugarcane is the major crops contributing to more than 50 % of the energy savings. With the principle of energy saved is energy produced, and the assumption that the cost of production for 1 KWhr of energy is rupees 5 the total savings will accrue to around 7 crores. For the farmers the anticipated energy saving benefit is of the order of 99 lakhs This is only an estimated figure. The actual saving depends upon the efficient utilization of the system by the farmers with special reference to water savings. Presently the farmers are not utilizing the system to its full potentiality. Hence there is an immediate need to educate the farmers for optimum utilization of the system to save more water and electrical energy through drip irrigation. `