3. DEPARTMENT OF AGRONOMY Seminar- I COLLEGE OF AGRICULTURE, RAICHUR Presenter, SANTHOSH U N PHD13AGR3011

4. IntroductionIssues related to Ground water depletion Saving water in rice-wheat fieldsApproaches for Water saving and water productivityCase studiesConclusionDiscussion

5. Major Cropping Systems in India Rice – wheat (10.5 m ha) Rice – rice (5.89 m ha) Cotton – wheat (1.09 m ha) Soybean – wheat (2.23 m ha ) Maize – wheat (1.86 m ha) P. millet - wheat (2.26 m ha) IGP “Food basket of India” Source: PDFSR., Modipuram, 2010

7. The majority of the rice is transplanted ?? Availability of labour for intensive cultivation Extensive irrigation infrastructure Mechanization Easy access to production inputs Better marketing and better weed management Best plant protection

8. But?? Now farmers are facing shortage of labour and water during the peak transplanting time and due to this transplanting is delayed sometime upto month of August which results in reduced yield. Sometime rice stands becomes patchy and optimum plant population can not be obtained. Due to intensive cultivation and long duration rice varieties wheat sowing is delayed sometimes upto January

9. Water Scarcity Per capital availability of water 40 - 60 % (1955-1990) Fresh water supplies 8 – 10 % (2010) Water table 0.3 – 1.0 m / year Leading to Increased Cost of pumping Aggravating energy crisis Humphreys et al. (2010)

10. Issues related to ground water depletion in Rice-Wheat fields Water table going down in the R-W belt of NW India Amount of water we need to save to arrest the declining water table Methods for reducing ground water depletion a) Methods for increasing recharge of ground water - Construction of recharge wells, adoption of soil conservation practices, rainwater harvesting, Renovation of village ponds b) Methods for reducing withdrawal of ground water - Delaying transplanting of rice, diversification from rice to other crops, Technologies like AWD, laser land levelling, raised beds and mulching

11. What do we mean by “Water saving “ in RW System Water saving – To cease unsuitable over exploitation of surface and groundwater resources and increase the amount of water available for non-agricultural purposes (eg. Urban, environmental, recreational). Thus water saving in RW system has the dual goals of using less water than is currently being used, while increasing production. From farmer point of view- “Water saving” using less irrigation water to grow a crop ideally with the same or higher yield, thus increasing irrigation water productivity (g grain/kg irrigation water).

12. Real water saving occurs when losses that cannot be recaptured are reduced or eliminated, however the magnitude of any water saving can vary considerably depending on the spatial and temporal scales of interest. (Loeve et.al.,2002) Real water saving is that which is achieved by reducing the unproductive water losses by soil water evaporation (Jalota et al., 2009) or evapotranspiration (Seckler, 1996). I+R = Percolation+ Runoff + Seepage +Evaporation+ Transpiration Temporarypermanent Wastage at field levelPlant levelSolution ??

13. Bouman, 2001 Components of water balance in rice fields Components of water balance in rice fields

14. Saving water in RW fields Generic approaches to saving water (Ws) or increasing water productivity (Wp) that can benefit both rice and wheat at the field scale - Laser land levelling, drainage recycling systems, the ability to forecast rainfall and irrigation water availability, and improved reliability of water supply system. Reducing seepage and percolation losses in RW fields - reducing percolation losses itself a real water saving - Confining rice to less permeable soils, reducing ponding depth and AWD irrigation, laser levelling and raised beds. Puddling for rice - There are some reports of similar yields for transplanted or direct seeded rice with and without puddling (Aggarwal et al.,1995; Humphreys et al., 1996; Kukal and Aggarwal 2003) Reducing evaporation losses - Reducing non-beneficial evaporation direct from the soil or free water lying on the field is a true water saving. -Evaporation can be reduced by mulching, by changing time of crop establishment

15. Sowing planting date -In NW India the evapotranspiration of rice declines from around 800 to 550mm as the date of transplanting is delayed from 1 may to june 30 -Irrigation water savings (25-30% or 720mm) can be achieved by delaying transplanting from mid-may to mid-june (Narang and Gulati., 1995) -Recommended practice in NW India is around mid-june. But, many farmers plant earlier this (57% in punjab) because of external factors.

16. Wheat yield under different dates Virender Pratap Singh,2011 GBPAU, Pantnagar

17. Varietal duration -Water can be saved by using varieties of shorter duration - Earlier maturity allows earlier harvest - Increasing the chance of timely establishment of a winter crop after rice and making more efficient use of stored soil water and winter rainfall instead of losing it as deep and surface drainage or transpiration by weeds Mulching -A few reports on the effect of mulching of wheat saved 25-100mm water, to reduced number of irrigations by one or irrigation time by an average of 17% (RWC-CIMMYT.,2003) -“Happy seeder”, which combines the stubble mulching and seed drilling functions into the one machine (Blackwell et al.,2004).

18. Construct a field channel for irrigation Before puddling harrow to close the cracks Maintain bunds, seal cracks, and close rat holes Make a farm ditch for proper drainage Ensure good field levelling Irrigate up to 5 cm, maximum Ways to use water wisely

19. Approaches to increase water savings in RW fields Real Water saving Laser levelling SRI AWD Aerobic Rice Stubble mulching Methods of irrigation scheduling and management Raised beds and furrows Tillage and crop establishment methods

20. Advantages of laser levelling Water is distributed homogeneously to the therefore, using efficiency of the present water will increase. It will be easier to control water and as a result surface and deep drainages will be easier. Uniform vegetation cover is provided (Meral and Temizel, 2006). Water lost during the application of water is reducing by 25%. Saving in irrigation water by 35-45% (Singh et al., 2008 and Chhatwal, 1999). This technology reduces weed problems and increases cultivable area by 3-6% (Jat et al., 2004).

21. Laser levelled plots prepared for R –W Production

22. Table 1: Water saving (%) due to laser leveling for different crops CropsWater SavingAverage water saving Maize22-3327.10 Wheat26-3326.00 Cotton26-4327.25 Paddy26-3026.33 Berseem2727.00 Pea2525.00 Potato25-2826.00 Avg. Water saving26.64 Ranjan Agarwal et al., 2010PAU, Ludhiana

23. Table2: Water saving in puddling of conventional leveled and laser leveled fields ParametersArea, haTime taken for irrigation, h Total quantity of water in m 3 Time saving for irrigation for puddling, % Water saving in irrigation for puddling, % CL0.3910.83390--- LL/PL0.398.7531518.2 CL- Conventional leveled land LL/PL- Laser/Precision leveled land UAS, Raichur Kanannavar et al., 2013

24. Water distribution efficiency in laser leveled and traditionally levelled field Jat et al., 2006 PDCSR., Modipuram

25. Table 3: Rice-Wheat and its components as affected by different levelling techniques TreatmentPlant heightProductive tillers (/m row ) Grains/spike1000 grain weight (g) Grain yield (t/ha) RiceWheatRiceWheatRiceWheatRiceWheatRiceWheat Laser131.695.510584824524425.734.47 Traditional127.787.49768774323395.354.23 Unlevelled111.876.18459683921.6394.253.75 CD at 5%16.912.313.714.39.55.3NS 0.470.32 SVPUAT, Meerut Naresh et al., 2014

26. Table 4: Total duration, applied water depth and water use efficiency as affected by laser land leveling and traditional leveling techniques TreatmentTotal duration min/ha Water depth Applied (mm ) Water / Irrigation (mm ) Volume of water applied ( m 3 ) WUE (kg/ m 3 ) RiceWheatRiceWheatRiceWheatRiceWheatRiceWheat Laser304912638103409063431633101.331.35 Traditional3414145695039210173498238421.071.10 Unlevelled41341857126050112293611849150.670.76 CD at 5%3852981839717158737860.210.23 SVPUAT, MeerutNaresh et al., 2014

27. Table 5: Water savings in different crops at different level of adoption of laser levelling CropWater saved AreaWater saved (ha m) at different level of adoption (%) cm(ha)10255075100 Maize9.51,52,5601,4473,6187,23510,85314,470 Wheat9.134,69,52031,57378,9321,57,8632,36,7953,15,726 Cotton9.55,41,0602,9497,37214,74422,11629,488 Paddy42.126,25,2041,10,5952,76,4865,52,9738,29,45911,05,946 Total67,88,3441,46,5633,66,4087,32,81610,99,22414,65,631 Ranjan Agarwal et al., 2010 PAU., Ludhiana

28. Advantages of Bed Planting Management of irrigation water is improved. Bed planting facilitates irrigation before seeding and thus provides an opportunity for weed control prior to planting Plant stands are better. Weeds can be controlled mechanically, between the beds, early in the crop cycle Wheat seed rates are lower. Less lodging occurs.

29. Wheat on Beds The irrigation water savings are likely to be due to faster irrigation times and reduced deep drainage and therefore the magnitude of the irrigation savings is likely to depend on soil type and depth to the water table.

30. Table 6 : Benefits of Bed Planting Observed in India Connor et.al., 2012PAU, Ludhiana

31. Wheat on FIRB beds

32. FURROW PLANTING IN BEDS

33. Multiple land use practices can saves water? Sowing of wheat on beds Planting canes in furrows Irrigation in furrows Sugarcane in wheat Wheat harvesting at maturity Sugarcane after wheat harvest Technical Bulletin 29 (2008) CCSHAU., Hisar

34. Table 7: Irrigation water savings by bed planting of wheat over conventional method Mollah et al., 2009BRRI, Gazipur (B’desh) Tillage option Water required at different times of irrigation (mm) Water saved over conventional (%) SowingCRIMax. TilleringGrain filling Total 2001-02 70cm bed5749412317046 80cm bed5549402116548 90cm bed5548392116348 conventional95897655315- 2002-03 70cm bed5848453518641 80cm bed5646443418042 90cm bed5545423217444 conventional94857960318-

35. Potential of Water saving in rice through System of Rice Intensification SRI, originated in Madagascar during 1980s by Henri Laulanie Increased yields in SRI compared to conventional methods were reported by several researchers (Thiyagarajan et al.,2005, Upoff, 2005 and Satyanarayana et al., 2006) Single seedling/hill Enhanced Water, Land and Labour productivity Wider Spacing Young seedlings Intercultivation with Cono weeder AWD More Organic matter Source: DRR Technical Bulletin No.75/2013

36. Table 8:Comparison of water inputs with grain yield, straw yield and Harvest index as influenced by SRI organic, SRI organic+inorganic and Best management practices Gopalkrishnan et al., 2013 ICRISAT., Hyderabad

37. Table 9: Yield and Water parameters under SRI and Conventional System MethodsYield (q/ha) No. of irrigation Water requireme nt (m 3 ) Water productivity (kg grain/ m 3 ) WUE (kg/ ha/ mm) Water required for 1kg grain % water saving Conventional54.0037152000.363.552815 - SRI72.6426121000.606.00166620.39 CD (0.05)6.73 -14130.040.53 - - Biplab Mitra et al., 2013 UBKV., Coochbehar

38. Table 10: Production Economics of rice under SRI and Convectional practice MethodsCOC (Rs/ha) Gross Income (Rs/ha) Net income (Rs/ha) BC ratio Irrigation Cost (Rs/ha) Saving (Rs/ha) Conventional3869258320196281.51240507150 SRI3724778451412042.1116900--- Biplab Mitra et al., 2013 UBKV., Coochbehar

39. Table 11:Grain Yield (t/ha) as influenced by different methods of crop establishment Grain yield (t/ha) Wet Season Dry Season TreatmentsBPT 5204 SwarnaDRRH 2 MeanMTU101 0 Shant i DRRH 2 Mea n Eco-SRI3.384.833.633.951.300.872.901.69 SRI5.056.004.755.273.321.754.963.34 Convention al 4.525.174.654.783.392.534.453.46 Mean4.325.334.342.671.694.12 C D (0.05) Main0.32Sub 0.15Main0.58Sub0.30 DRR, Hyderabad Mahender Kumar et al., 2011

40. Table 12: Water quantity (m 3 ) as influenced by cultivars and crop establishment methods Wet Season Dry Season TreatmentBPT 5204 SwarnaDRR H2 MeanMTU 1010 ShantiDRRH2Mean (%) ws Eco-SRI723573557912750067156697674067177109 45.55 SRI925288359481918985638738856586228906 31.78 Conventio nal 153501435015099149331117211173111851117713055 Mean106121018010831 10541 88178869883088399690 38.66 DRR, Hyderabad Mahender Kumar et al., 2011

41. Cracking pattern in Direct Seeded and Transplanted Rice Fields DIRECT SEEDED RICE Unpuddled fieldTRANSPLANTED RICE Puddled field Transplanting – a labour intensive operation Puddling – a water intensive operation

42. During land preparation, Bulacan, Phillipines, Cabangon and Tuong (2000) Control Cracks Ploughed

43. Influence of tillage practices on Crack Parameters Management Cracking pattern in Unpuddled &DSR plot after harvest Cracking pattern in puddled & tranplanted plot after harvest

44. Table13: The comparison of the measured average parameters as influenced by crack width and depth of irrigation water Parameter Crack width Depth of irrigation C0C1.5C2.5LSD value D0D2.5D5LSD value Grain yield (t/ha) 3.134a2.729b2.300c0.20422.628b2.675b2.860a0.1482 Blank grain percentage 18.33a19.47a21.07a4.28215.91b19.06ab23.90a5.900 1000 grain weight (g) 22.17a21.02b20.89b0.939920.58b21.77a21.73a0.9399 Ear length (cm)29.52a28.55ab27.24b1.79727.35b28.19ab29.77a1.797 Number of tillers 17.45a15.22b14.07b2.24214.48b15.59ab16.67a1.627 WUE (g/m 3 )293.8a268.0b189.9c22.95293.2a243.7b214.8c22.95 Behrooz et al., 2010 Isfahan., Iran

45. Alternate Wetting and Drying – Smart water technique for Rice By using a simple water level gauge and implementing smart but simple water management techniques, farmers can reduce water usage in paddy rice by 15-30 per cent without compromising yields.

46. About panipipe A PaniPipe is a 40cm length of 15cm diameter plastic pipe or bamboo, with drilled holes, which is sunk into the rice field until 20cm protrudes above soil level. When the water level inside the PaniPipe drops to 15cm below ground level, the field is ready to be re-flooded. This threshold is called ‘safe AWD’ as it does not impact on yield. By using PaniPipes and implementing the smart but simple AWD technique, farmers save up to 30% of the nearly 5,000 litres of water commonly used to produce 1kg of unmilled rice. The savings in water has increased farmers’ income by more than 30%; often from a net loss to a net gain.

47. In Vietnam and Bangladesh farmers reported yield increases of more than 10%. In the Philippines, more than 100,000 farmers have adopted AWD, which has also reduced conflicts over water in shared canal irrigation systems. In Bangladesh, trials have shown reductions in water consumption of 15-30%, translating into a reduction in pumping costs and fuel consumption and an increased income of US$67-97 per hectare.

48. AWD in Rice Safe AWD maintains yield while giving very large irrigation water savings in transplanted rice on permeable soils with deep watertables, in comparison with continuously flooded rice. The reduction in irrigation amount is likely to be due to reduced deep drainage, with little effect on ET and WPET. In practical terms, adoption of safe AWD is generally not possible for farmers dependent on canal irrigation or electricity for groundwater pumping because of unreliable and limited supply of water or electricity. There is no incentive to adopt safe AWD because of the low prices of water and electricity. safe AWD would be beneficial for farmers who purchase diesel to pump groundwater. Areas where diesel powered pumps are commonly used should be identified and the technology could be promoted immediately.

49. Yield Low High Water availability Flooded lowland Upland Crack plowing Compaction Good puddling …….. ‘Safe’ AWD Aerobic rice various response options to water scarcity Diversification (non rice crops)

50. Table14: Water savings for different water saving irrigation treatments WSI treatmentIrrigation water (mm) Water saving relative to control mm % SII (Control)86100 AWD-171115017.4 AWD-273612414.4 AWD-3781799.2 AWD-47629811.4 SWD-1783789.1 SWD-2846141.7 SDC703158 IndonesiaSujono et al., 2011

51. Table 15: Alternate wetting and drying irrigation water use efficiency for different treatments Treatments Total water use (cm)Average total water used (cm) Water use efficiency (kg/ha/cm) BRRIdhan 28BRRIdhan29 T1112.20122.20117.258.53 T292.2097.2094.769.98 T387.2092.2089.769.89 T482.2087.2084.769.19 T1- Continuous submergence (1 to 7 cm standing water T2- Application of 5cm irrigation water when water level in the pipe fell 10cm below GL T3-Application of 5cm irrigation water when water level in the pipe fell 20cm below GL T4- Application of 5cm irrigation water when water level in the pipe fell 30cm below GL BAU., Bangladesh Oliver et al., 2008

52. Table 16: Effect of water –saving irrigation on rice yield and water use in lowland conditions in Asia N regime (kg/ha) Tuanlin, 1999 Tuanlin, 2000 CSASNSCSASNS 00.50 a0.58 a 180 (2 splits)0.980.830.94 b1.13 b 180 (4 splits, early) 0.900.950.92 b1.07 b 180 (4 splits ’99 6 splits’00) 0.861.030.99 b1.07 b Munoz 2001 CSASNSvASNS 00.73 a0.87 a0.78 a 900.11 b1.16 b1.24 b 1801.20 b1.34 b1.48 c CS- continuously subbmerged ASNS- alternately submerged –nonsubmerged during the whole cropping season ASNSv- ASNS- alternately submerged –nonsubmerged in the vegetative phase only Water Productivity (kg grain (m 3 ) water input) Belder et al., 2004

53. Tillage practices and crop establishment methods Establishment method of rice Transplanting Puddled Manual Mechanical Unpuddled After dry Tillage After Zero Tillage Direct seeding Wet seeding Puddled field Broadcasting Line sowing Unpuddled field Broadcasting Line sowing Dry seeding After dry tillage After Zero tillage (+M/-M) Water seeding

54. Table 17: Comparison of grain yield (t/ha) in Direct seeded and Transplanted rice under different Ecosystem DSRPTRRice EcologyCountryReference 5.505.40Shallow wetland + irrigatedJapanHarada et al., 2007 3.833.63Rainfed lowlandThailandMitchell et al., 2004 2.933.95IrrigatedPakistanFarooq et al., 2009 5.405.30Favorable irrigatedNepalHobbs et al., 2002 5.595.22Favorable irrigatedIndiaSharma et al., 2004 5.385.32IrrigatedSouth KoreaKo and Kang., 2000 6.096.35Rainfed lowlandIndiaTripathi et al., 2005 6.606.80Rainfed lowlandIndiaSingh et al., 2009 Ekta Joshi et al., 2013

55. Table 18: Water productivity of rice as influenced by seeding technique Method of SowingIrrigation water applied (cm) Water Productivity (kg grain/m 3 of irrigation water) 2002200320022003 Direct seeding Puddling125890.3900.837 Drum seeding127910.3850.848 Compaction122870.4200.835 Line Sowing without compaction/puddling 1461130.2060.525 Transplanting Transplanting on the day of sowing 1701400.3400.566 Transplanting 25 DAS1501200.2710.576 PAU., Ludhiana Gill et al., 2006

56. Table 19: Influence of irrigation management on irrigation requirement, irrigation use efficiency, water requirement and field water use efficiency of rice Irrigation regime IR (mm)IUE (kg grain grain/m 3 of irrigation water WR (mm)FWUE (kg grain/m 3 of irrigation water) 20022003200220032002200320022003 Contineous Submergence 120010800.320.28149715400.230.21 1-day drainage 8406800.340.44113711500.32 3-day drainage 6005600.350.6389710200.420.37 IARI., New DelhiRamakrishna et al., 2007

57. Table 20: Irrigation water amount (mm) in PTR and DSR at 20kpa 2008 2009 SchedulePTRDSRRainfallPTRDSRRainfall Pre sowing irrigation_79(01)5- 0 Sowing after 27 DAS/Transplanting Negligible100(03)233Negligible250(05)101 Puddling79(01)-0150(02)_0 27-41 DAS (15 d continuous flooding in PTR) 731(15)95(02)50275(12)_75 41 DAS to harvesting200(04) 534400(08)250(05)487 Total1010(20)474(10)822825(22)579(11)663 Sudhir Yadav et al.,2011 PAU., Ludhiana

58. Table 21:Water balance components by dry seeded and Puddled transplanted rice (2008 ) PAU., Ludhiana Sudhir Yadav et al.,2011

59. Table 22:Water balance components by dry seeded and Puddled transplanted rice (2009 ) Sudhir Yadav et al.,2011

60. Grain Yield of Rice as affected by Establishment method and Irrigation Schedule Sudhir Yadav et al.,2011PAU., Ludhiana

61. Table 23: Comparison of Water Inputs as Influenced by Different Cultivation Methods and Irrigation Regimes TreatmentsWater Input (m 3 /ha) Water Productivity (Kg/m 3 ) Liters of Water Kg/grain % Of Water Saved Over Flooding SRI- Flood (M 1 I 1 )146950.362812.44 SRI- Saturation(M 1 I 2 ) 116200.482079.64220.92 SRI- AWD (M 1 I 3 )96950.631590.64834.00 NTP-Flood (M 2 I 1 )159950.234400.275 NTP-Saturation (M 2 I 2 ) 121200.323143.96924.22 NTP-AWD (M 2 I 3 )109950.372699.81631.25 WALAMTARI, Hyderabad Shantappa Dutturganvi et al., 2014

62. Yield and water productivity comparison in different cultivation methods with water regimes Shantappa Dutturganvi et al., 2014 WALAMTARI, Hyderabad

63. Irrigation water use of PTR and DSR as affected by irrigation scheduling on a clay loam soil PAU., Ludhiana Sudhir Yadav et al., 2010

64. Table 24: Comparison of seasonal water requirement between lowland flooded rice and aerobic rice Seasonal water requirement (mm) Lowland flooded riceAerobic rice Land preparation150–300100 Evaporation200100 Transpiration400 Seepage and percolation500–1.500335 Application loss (at 60% efficiency) 335 Total seasonal water requirement 1650–3000935 Lampayan and Bouman (2005)

65. Zero till Wheat  Adoption rates of zero till wheat are far higher than with any other improved technology for RW systems, with adoption on over 10% of the RW area of India by 2003–2004.  It increased profitability as a result of lower establishment costs.  Irrigation water saving of at least 10% (at least 20–30 mm) in comparison with conventional practice, while yields are generally slightly higher, leading to higher Water productivity.  Experimental studies indicate that reductions in irrigation amounts of up to 30% are possible.

66. Mulching Mulching offers the potential to reduce evaporation from wheat by 30–40 mm, which will reduce the number of irrigations needed by one in some years. Reduction in evaporation is offset by increased transpiration, and that under well- irrigated conditions transpiration efficiency is reduced, resulting in similar WPET with and without mulch. Under limited water conditions where mulching reduces water deficit stress and loss of yield, WPET is increased.

67. Table 25: Yield and its components and water use efficiency of rice under different cultivation Treatment1000 grain weight (g) Unfilled grain rate (%) Yield (kg/ha) IWUE (kg /m 3 ) WUE (kg /m 3 ) Flooded cultivation 22.76a15.31b6811.5a0.341c0.311b Non flooded without mulch 21.36a18.99a4716.0b0.573b0.462b Non flooded with straw mulch 21.99a15.96b6489.0a1.076a0.810a Nanjing Agricultural University, China Jiang –tao Quin et al., 2006

68. Replacement of Rice – Crop diversification can saves water in RW cropping system? Replacing rice with another summer crop will greatly reduce the amount of irrigation water applied, with many benefits. In canal irrigated areas with saline ground waters, replacement of rice will reduce water depletion and the rate of water table rise and associated problems. But replacement of rice with other summer crops will not reduce the problem of groundwater depletion in areas with fresh groundwater, where groundwater is the main source of irrigation water and ET is the only source of water depletion, unless the alternative crop has lower ET than that of rice.

69. Table 26: Effect of Tillage/Crop establishment in Rice Based Cropping Systems(REY t/ha) Treatment (Tillage Practices) Rice- wheatRice- chickpeaRice- mustard Direct-seeding (dry bed)14.8413.9014.31 Drum-seeding (wet bed)14.9113.8813.66 Mechanical transplanting (puddled) 13.7511.0712.28 Mechanical transplanting (unpuddled) 13.9912.6012.66 Manual transplanting (puddled)13.4310.8912.22 Gangwar et al. (2006) PDFSR., Modipuram

70. Table 27: Crop yield and Water use efficiency of rainfed direct sown rice cultivars in upland VarietyPanicle Weight (g) Filled Grains /panicle Grain yield (t/ha) Water used (mm) WUE (kg/ha/m m) Anjali1.982.22.685644.75 RR166-6451.768.42.365204.35 RR348-61.984.82.145703.75 RR361-11.677.82.245504.07 RR 51-10.956.22.155803.70 RR 165-11602.3117.42.556074.20 Vandana2.7103.72.755275.22 Chali2.198.81.895543.41 Mean1.982.42.285434.19 CD (p=0.05)0.4817.60.2729.10.30 BCKV., NadiaGoswami et al., 2007

71. Grain yield (t/ha) of different rice cultivars under direct seeding and puddle transplanting in Karnataka Source: www.uasraichur. edu.in

72. Table 28: Effect of water management treatments on rice yield TreatmentsRice yield (t/ha) Water use in R-W system(ha.Cm.) Saving (%) DP4.73152- HC4.5712020.5 DP-Irrigation on disappearance of water HC- Irrigation at hair line crack stage Gangwar et al., 2006PDFSR., Modipuram Site Specific Water management Practices in R-W system

73. Table 29: Performance of paddy crop and consumption of irrigation water in relation to soil matric tension based irrigation scheduling Soil matric tension (kpa) Paddy yield (t/ha)Irrigation water use (cm) Irrigation water saving (%) 10±26.44111.824.6 16±26.40102.331.0 20±26.2189.539.6 24±25.6180.046.1 2-d fixed interval6.43148.3 - Kukul et al., 2010 PAU., Ludhiana

74. Table 30: Water Productivity and Requirement for Aerobic Rice Water regimes Water input (ha mm) Mean yield (kg/ha) Water productivity (kg grain/ha mm) Water requirement (lit/kg grain) Kanp ur DRRKanpurDRRKanpurDRRKanpurDRR IW/CPE- 150% 88011333.265.163.74.5527032198 IW/CPE- 100% 617 -29.9 978 -13.7 2.954.964.785.072009 -22.6 1992 -10.3 IW/CPE- 75% 478 (45.7) ------2.68……5.6------……..------ Source: DRR Technical Bulletin No.75/2013

75. Table 31:Water requirement of aerobic rice system, Rabi 2011 (DRR) Water regimeYield (kg/ha)Irrigation (mm) WP (kg grain/mm) WR (L/kg grain) P-IW/CPE- 150% 5.1611334.552198 P-IW/CPE- 100% 4.96978 (-14%)5.071972 (10%) UP-IW/CPE- 150% 4.44983 (-13%)4.522212 UP-IW/CPE- 100% 4.15828 (-27%)5.011996 (9%) Source: DRR Technical Bulletin No.75/2013

76. Indirect Approaches of water saving Virtual Water Trade: When a country imports a tonne of wheat or maize, it is in effect, also importing "virtual water", i.e. the water required to produce that crop. Trade in virtual water generates water savings for importing countries. Global water saving as a result of international trade of agricultural products has been estimated at about 350 billion m3/year. To maintain food security or food self- sufficiency, many countries in the arid and semi arid regions have over-exploited their renewable water resources. Trade can help mitigate water scarcity if water- short countries can afford to import food from water-abundant countries. But political and economic factors are stronger drivers and barriers than water. Many countries view the development of water resources as a more secure option to achieving food security and livelihood of its population. Large water exporting countries may influence the policies of recipient countries. Therefore, there is a strong need to develop a set of principles/rules governing virtual water trade otherwise conflict may prevail over cooperation

77. CONCLUSION