Rice Production Course Water-Saving Irrigation in Rice R. Lampayan CSWS, IRRI Content • Introduction: the water crisis • Water-saving technologies • Practical experiences • Sustainability issues • Conclusions IRRI: Rice Production Course Rice grows under lowland conditions: puddled soil, permanently flooded IRRI: Rice Production Course Rice and water • 75% of rice is irrigated (75 m ha) • Rice requires much water: 3000-5000 l kg-1 rice • Irrigated areas consume 80% of all fresh water used; Asia: > 50% of this is for rice IRRI: Rice Production Course Pressure to produce more food (rice) is getting greater because of ever increasing population But also: More people want • more industry • more drinking water • more cities • more swimming pools • more…. => Water is getting scarce and expensive IRRI: Rice Production Course Is this the future for rice production……. ? IRRI: Rice Production Course Competition, some examples in rice areas…. Beijing: 2001: ban on flooded rice ZIS (160,000 ha)-city, industry Irrigation Other Uses Sectoral Share ZIS: 100 90 80 70 60 50 40 30 20 10 0 1965 1970 1975 1980 1985 YEAR Ganges river: India-Bangladesh Cauvery river: Karnataka-Tamil Nadu IRRI: Rice Production Course 1990 1995 2000 Reduced river flows IRRI: Rice Production Course Tubewells and pumps for irrigation 70 60 50 40 India China 30 20 10 0 1966 1995 India (2000): 5-6 million irrigation tubewells N China (2001): 3-4 million irrigation tubewells IRRI: Rice Production Course Groundwater depletion 1-1.5 m/y 0.7 m/y Arsenic! IRRI: Rice Production Course Conclusion Need to grow rice using less water in water-scarce or water-costly areas • Produce enough rice for growing population • Decrease cost of rice production • Save ‘little’ water in rice => free-up ‘much’ water for irrigation elsewhere and for use by other sectors (industry, cities, other crops) IRRI: Rice Production Course To mitigate the looming water crisis, we need to “Produce more rice with less water” IRRI: Rice Production Course Field water balance lowland rice IRRI: Rice Production Course Water requirements in lowland rice Land preparation Evapotranspiration - wet season - dry season Seepage & percolation - heavy clays - loamy/sandy soils Total season Typical value Daily mm d-1 Season (100 d) mm 175-750 4-5 6-7 400-500 600-700 1-5 25-30 100-500 2500-3000 : 675-4450 mm : 1500 mm IRRI: Rice Production Course Water-saving measures • • • • • • • • • Good puddling Good bund maintenance Land leveling Crack plowing Short land preparation phase Communal seed beds Efficient use of rainfall (cropping calendar) Direct wet seeding …… IRRI: Rice Production Course Water-saving irrigation technologies: Reduce seepage, percolation and evaporation • Saturated soil culture • Alternate wetting and drying • Aerobic rice IRRI: Rice Production Course Field water depths in alternate wetting Field water depth (mm) 60 50 40 30 20 10 0 0 10 20 transp. Early recovery tillering 30 Late tillering 40 50 60 70 PI to complete flowering 80 90 100 110 grain filling Maturity Days after Transplanting IRRI: Rice Production Course Continuously flooded Alternate wetting and drying Yield (t/ha) 10 9 8 7 6 5 4 3 2 1 0 TL99 TL00 IRRI: Rice Production Course PR01 Continuously flooded Alternate wetting and drying Irrigation water (mm) 800 700 600 500 400 300 200 100 0 Tuanlin 1999 Tuanlin 2000 PhilRice 2001 Note: heavy clay soil with shallow groundwater (0-30 cm deep) IRRI: Rice Production Course Guimba 88-90 (Tabbal et al., 2002) Silty clay loam, groundwater 70-200 cm Yield (t/ha) 8 6 1988 4 1989 1990 2 0 500 1,000 1,500 2,000 IRRI: Rice Production Course 2,500 Total water (mm) A fundamental approach to reducing water requirements in rice? Treat rice like any other (irrigated) crop: No puddling, no standing water, aerobic soil IRRI: Rice Production Course Upland rice Breeding: Aerobic soil Drought tolerant Weed competitive Adverse soil conditions Low inputs (!) => Stable but low yields Unfavorable uplands IRRI: Rice Production Course Different idea of rice like upland crop Breeding: from upland rice… Aerobic soil Input responsive Lodging resistant Weed competitive => Stable and high yields Lowland HYV traits Water-short irrigated areas ‘Favorable’ uplands IRRI: Rice Production Course Improved upland… Dryland Rice… Han Dao… Aerobic Rice… IRRI: Rice Production Course New Aerobic Rice Girls… IRRI: Rice Production Course Early evidence: Brazil • Active program to develop upland rice varieties and management techniques since the 80’s => High-yielding aerobic varieties: 5-7 t ha-1 with high inputs • State of Mato Grosso: 250,000 ha commercial production (sprinkler irrigated) IRRI: Rice Production Course Aerobic rice, Mato Grosso, Brasil Guimarães and Stone, 2000 IRRI: Rice Production Course Early evidence: North China • Program to improve upland rice => Aerobic rice varieties with yield potential of 6-7 t ha-1 Adoption on estimated 190,000 ha (2001) in • Rainfed areas where rainfall is insufficient to sustain lowland rice production • Irrigated areas where water is scarce/expensive • Salt-affected areas • Flood-prone areas Q: What is water use, how to manage the crop? IRRI: Rice Production Course IRRI: Rice Production Course Hydrology field experiment Beijing, 2001: Explore aerobic rice yield and irrigation water use IRRI: Rice Production Course IRRI: Rice Production Course IRRI: Rice Production Course Total water input (mm) 1400 1200 1000 800 600 400 200 0 Flood W1 W2 W3 W4 W5 Water treatment (Rainfall) IRRI: Rice Production Course Yield (t/ha) 9 8 7 6 5 Lowland Aerobic 1 Aerobic 2 4 3 2 1 0 1394 644 577 586 519 469 Flooded ---------------- Aerobic -----------------IRRI: Rice Production Course Water (mm) IRRI, Philippines: 3-4 varieties each season one flooded and one aerobic treatment IRRI: Rice Production Course IRRI, 2001 DS: yield (t ha-1) in K6/7 8 7 6 5 Flooded Aerobic 4 3 2 1 0 IR43 B6144F Apo+ Fertilizer: 180-60-40 kg ha-1 NPK Pests and diseases: mole crickets (aerobic), stem borer, sheath blight; lodging in B6144F IRRI: Rice Production Course IRRI, 2002 DS: yield (t ha-1) in K6/7 8 7 6 5 Flooded Aerobic 4 3 2 1 0 IR43 IR64 Apo+ Fertilizer: 120-60-40 kg ha-1 NPK IRRI: Rice Production Course Magat Water input, including land preparation (mm) 2000 1800 1600 1400 1200 1000 800 600 400 200 0 Flooded Aerobic Irrigation Rainfall IRRI: Rice Production Course WS2002 DS2002 WS2001 DS2001 WS2002 DS2002 WS2001 DS2001 Lining of bunds Practical experiences IRRI: Rice Production Course Case study Tarlac & Nueva Ecija: Introducing alternate wetting and drying to farmers using shallow or deep wells for irrigation IRRI: Rice Production Course Monitoring inputs: Irrigation water, seeds, fertilizer, pesticides, labor use, etc. And outputs: Grain yield and quality IRRI: Rice Production Course Irrigation water used (mm) IRRI: Rice Production Course Grain yield (t/ha) IRRI: Rice Production Course Comparison between farmers’ practice and alternate wetting and drying (dry season 2001) Farmers’ practice Alternate wetting and drying Difference Total water used* (mm) 500 310 190 Pump O&M cost ($ ha-1) 112 69 43 Yield (t ha-1) 5.7 5.5 0.2 Particulars * From transplanting up to harvesting IRRI: Rice Production Course Partial budget comparison ($ ha-1) Farmers’ practice Alternate wetting and drying Savings Gross benefits 944 911 -33 Variable irrigation cost 148 96 52 ‘Net’ benefits 796 815 19 Particulars Comments irrigation manager and farmer community: can irrigate 30% more area with same amount of water !! IRRI: Rice Production Course Case study Tarlac and Nueva Ecija, Philippines: Aerobic Rice Crop establishment (traditional technologies) IRRI: Rice Production Course Farmer-participatory development; central Luzon. 2003: develop also modern technologies Laser-guided land leveling Automated seeder with basal fertilizer application Labor saving Efficient fertilizer use IRRI: Rice Production Course Flush irrigation of the field only! IRRI: Rice Production Course Weed control: traditional technology (plough, lithao, sagad) IRRI: Rice Production Course IRRI: Rice Production Course Results aerobic rice WS 2002; Canarem, Tarlac IRRI: Rice Production Course Varieties: • Apo • UPLRI5 • Magat (Hybrid) IRRI: Rice Production Course Grain yield (T/ha) 7 Low-tech High-tech Yield range: APO (HT) (LT) Yield range: APO : 4.1 - 5.9 t/ha UPLRI-5 : 4.0 - 5.6 t/ha Magat : 4.5 - 5.4 t/ha : 2.0 – 6.6 t/ha : 2.0 – 6.0 t/ha UPLRI-5 (HT) : 3.3 – 5.3 t/ha (LT) : 2.2 - 5.3 t/ha APO IRRI: Rice Production Course UPLRI-5 Sustainability issues with increased aerobic conditions IRRI: Rice Production Course Aerobic rice, Mato Grosso, Brasil Guimarães and Stone, 2000 Rice production system Rice after 3 years soybeans Rice after 1 years soybeans Rice monocrop (5 years) Yield (kg ha-1) 4,325 2,577 1,160 Fertilization 300 kg of 4-30-16 N,P,K at planting; 150 kg ammonia sulfate 50Course DAS IRRI: Riceat Production Field experiments at Dapdap (dry season) • Irrigation experiment (4 treatments) • Nitrogen experiment (5 treatments) Mixed upland-lowland area with sandy-loam soil IRRI: Rice Production Course No more crop growth after tillering…. IRRI: Rice Production Course Roots affected by nematodes Healthy Field experiment IRRI: Rice Production Course Rep V1 Variety V2 V3 W1 W2 W3 W4 1.26 0 0 0.33 0.76 0 0 0 0.96 0 0 0 0.99 0.00 0.00 0.11 II W1 W2 W3 W4 4.14 0 0 0.47 4.69 0 0 0.68 3.07 0 0 1.11 3.97 0.00 0.00 0.75 III W1 W2 W3 W4 3.52 0 0 0.52 4.29 0 0 0.17 3.93 0 0 0 3.91 0.00 0.00 0.23 IV W1 W2 W3 W4 3.97 0 0 0.71 5.68 0 0 0 4.87 0 0 0 4.84 0.00 0.00 0.24 I Treatment Mean IRRI: Rice Production Course Irrigation experiment Varieties: V1 = Apo V2 = Magat V3 = PSB Rc 98 Irrigation: W1=2/week W2=1/week W3=1/2 week W3=variable Rep V1 Variety V2 V3 N1 N2 N3 N4 N5 0.46 0.91 0.08 0.24 0.71 0 0.58 0.21 0.08 0.35 0 0.75 0.63 0.29 0.12 0.15 0.75 0.31 0.20 0.39 II N1 N2 N3 N4 N5 0.94 0.12 0.42 0.73 3.27 0 0.59 0.54 1.5 2.46 0.37 1.18 1.01 1.96 1.54 0.44 0.63 0.66 1.40 2.42 III N1 N2 N3 N4 N5 0 0.3 1.65 1.04 1.03 0.82 0.45 2.25 0 1.29 0.68 1.6 0.26 0.53 1.35 0.50 0.78 1.39 0.52 1.22 IV N1 N2 N3 N4 N5 0.74 2.6 2.33 2.6 0.28 1.41 2.03 1.12 1.68 0.54 1.4 0.28 0.54 1.44 0.29 1.18 1.64 1.33 1.91 0.37 ! Treatment Mean IRRI: Rice Production Course Nitrogen experiment Varieties: V1 = Apo V2 = Magat V3 = PSB Rc 98 Nitrogen: N1 = 0 kg N2 = 100 kg N3 = 140 kg N4 = 180 kg N5 = 220 kg Nematode count at harvest; nitrogen experiment 4500 4000 3500 3000 Apo Magat PSB Rc 98 2500 2000 1500 1000 500 0 0 100 140 180 IRRI: Rice Production Course 220 kg N ha-1 Nematode count from lowland rice farmers 4500 4000 3500 3000 2500 2000 1500 1000 500 0 1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 IRRI: Rice Production Course Nematode count/g fresh root (Meloidogyne graminicola) 2000 2001 2002 2003 Wet season Dry season Wet season Dry season Wet season Dry season AA 6 875 491 2530 1499 2089 AF 9 279 11 1760 27 3054 FF 2 6 4 134 34 380 Sampled from roots at harvest Aerobic Flooded IRRI: Rice Production Course Wet season Conclusions for Controlled Irrigation An average water savings of about 20% was attained in both deepwell and shallow tubewell systems. Forty percent (40%) of water savings has also been attained in some fields. No significant yield difference has been observed between CI and FP plots. Farmers achieved an average increased net profit of about $20 per ha in deepwell and shallow tubewell systems. IRRI: Rice Production Course Conclusions tropical aerobic rice Where are we after 2 years in the program? 1. Identified varieties with yield potential of 6 t ha-1, using about half the water used in lowland rice (Apo, Magat, UPLRI5, and more) 2. Rough management recommendations that can deliver about 4.5 t ha-1 of the yield potential 3. Established a successful partnership to fully develop the aerobic rice technology (IRRI, NIA, PhilRice and farmers) 4. Under water scarcity: extremely urgent to develop sustainable crop rotations (nematodes!) 5. We stand at a successful beginning IRRI: Rice Production Course AWD, aerobic rice “Target domain” Yield Diversification (nonrice crops) Crack plowing Compaction Good puddling …….. AWD Flooded lowland Aerobic rice Upland Low High Water availability IRRI: Rice Production Course