WATER SAVING POTENTIAL OF SYSTEM OF RICE INTENSIFICATION RESEARCH FINDINGS IN INDIA AND ITS IMPACT

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1 WATER SAVING POTENTIAL OF SYSTEM OF RICE INTENSIFICATION RESEARCH FINDINGS IN INDIA AND ITS IMPACT Mahender Kumar 1, Sudhakara.T. M 2, K. Surekha 3, Ch. Padmavathi 4 and V. Ravindra Babu 55 ABSTRACT A field experiment was conducted on a clay loam soil at Indian Institute of Rice Research (IIRR) Rajendranagar, Hyderabad, Telangana State during wet and dry seasons of and to Evaluate irrigation regimes and nitrogen management practices on production potential of rice (Oryza sativa (L.) under mechanized SRI and SRI methods. The treatments consisted of two planting methods (Mechanized system of rice intensification (MSRI) and system of rice intensification (SRI)) as main treatments, three irrigation regimes (saturation, 5 cm irrigation at three and five days after disappearance of ponded water) as sub treatments and four nitrogen management practices (RDN % through inorganic, RDN - 75 % inorganic and 25 % organic, Leaf Colour Chart (LCC) based nitrogen application and Soil Test Crop Response (STCR) based nitrogen application as sub-sub plots. SRI recorded significantly superior in terms of root growth characteristics, yield attributes, grain and straw yield over MSRI. Irrigation maintained at saturation level produced significantly higher growth parameters, yield attributes, grain and straw yield which were comparable with irrigation at 3 DADPW. MSRI and SRI performed at par with respect to B:C ratio. Significantly higher gross and net returns were recorded with SRI over MSRI. The total labour saving was % in MSRI as compared to SRI. The saving of the water to the extent of % accounts to nearly US$ /ha and US$ /ha during wet and dry seasons respectively and thereby reducing production cost especially under water scarce conditions. Further collaborative research studies are useful in SRI and its modifications to mitigate climate change effects (methane emissions) and for enhancing resource conservation and for wide scale adoptability across the country. Keywords: Methods of crop establishment, water productivity, Rice-rice system, System of Rice Intensification (SRI) and Mechanized System of Rice Intensification 1. INTRODUCTION Rice is the principal staple food for 65 % of the population of India and demand for rice is expected to rise due to increase in population (1.6 % per year), with reduced area of 40 million ha in the next years. As per the fourth Advance Estimates for , the production of rice in India is million tonnes. Rice covers one third of total cultivated area of India and provides food to more than half of the population. 1 Principal Scientist Agronomy, IIRR Rajendranagar Hyd INDIA kumarrm213@gmail.com, Fax: PhD Scholar, IIRR, Rajendranagar, Hyderabd INDIA 3 Principal Scientist Soil Science, IIRR Rajendranagar Hyderabad INDIA 4 Principal Scientist Entomology, IIRR Rajendranagar Hyderabad INDIA 5 Director, IIRR Rajendranagar Hyderabad INDIA 1

2 This makes it India s largest produced food crop both by area under cultivation as well as production. India is second largest producer of rice after China; produces one fifth of the world s rice; and is largest exporter of rice. Rice is the staple crop in eastern and southern part of the country and is very important crop in terms of national food security. The projected demand has to be met in the background of declining land and water resource, scarcity of labour and costly inputs. The System of Rice Intensification (SRI) an alternative way to grow traditional flooded rice (Laulanie, 1993). SRI method reportedly enhances the yields of rice through synergy among several agronomic management practices. SRI works by integrating processes such as reduced plant population, transplanting single young seedling, wider square planting, mechanical weeding with need based fertilizer application and optimum use of water for better growth especially soil aeration (Kumar and Shivay, 2004). The SRI advocates synergies among the unconventional management practices that unlock the physiological potential of rice, with results that challenge prevailing notions of yield ceilings for this food staple (WWF-ICRISAT, 2010). Transplanting of rice manually is a laborious, time consuming and causes drudgery. Non availability of labors for transplanting at appropriate time leads to late planting resulting in poor yield (Awan et al., 2008). Rice transplanting manually alone requires about man days ha-1, which is roughly 25 % of the total labour requirement of rice production (Swain et al., 2013). Under such situation, a less expensive and labour saving method of rice transplanting without reduction in grain yield is the need of the hour. The mechanical transplanting of rice has been considered the most promising option, as it saves labour, ensures timely transplanting and attains optimum plant density that contributes to high productivity. Keeping these points in view the present research on Evaluation of irrigation regimes and nitrogen management practices on production potential of rice (Oryza sativa (L.)) under mechanized SRI and SRI methods was carried out to assess the performance of rice under mechanized SRI and SRI method, to study the effect of irrigation regimes on growth and yield of rice under mechanized SRI (MSRI) and SRI method and to study the effect of different nitrogen management practices on growth and yield of rice under MSRI and SRI methods. 2. METHODS The studies were conducted at Indian Institute of Rice Research Farm, Hyderabad (Telangana) in clay loam soils ( to ) for two consecutive wet (kharif) and dry (rabi) seasons to investigate water saving potential, and grain yield by comparing the plants grown with different crop establishment methods (SRI and MSRI methods ). The treatments consisted of two planting methods (Mechanized system of rice intensification (MSRI) and system of rice intensification (SRI)) as main treatments, three irrigation regimes (saturation, 5 cm irrigation at three and five days after disappearance of ponded water) as sub treatments and four nitrogen management practices (RDN % through inorganic, RDN - 75 % inorganic and 25 % organic, Leaf Color Chart (LCC) based nitrogen application and Soil Test Crop Response (STCR) based nitrogen application as sub-sub plots. 2.1 Physico-chemical properties of the experimental soil The soil samples were collected randomly from the experimental field from 0-30 cm depth and were analyzed for their physico-chemical properties by adopting standard procedures. The results of the analysis are presented in Table 1. 2

3 Varadhan (DRR Dhan 36) is a derivative of indica / japonica cross with mid early duration that matures in days, possessing long and heavy panicle, erect flag leaf, medium tillering, highly responsive to fertilizers and suitable for irrigated medium lands 2.2 System of Rice Intensification (SRI) Puddling of the field was done similar to conventional nursery bed preparation and then raised (about 10 cm) bed of 1.0 m width and 10.0 m length was prepared. Around the bed, 40 cm drainage cum irrigation channel was prepared. On this nursery bed, soil and vermicompost (1:1) mixture was spread to 4-5 cm thickness. Nursery bed was prepared one day before sowing of seeds. Seeds were soaked for 24 hours and incubated in moist gunny bag for 24 hours (Plate 3). The sprouted seeds were broadcasted uniformly on nursery bed. Seed rate at 5 kg in 100 m-2 area of nursery bed was used and it was sufficient to transplant one hectare main field. After broadcasting the sprouted seed, 1:1 soil and vermicompst mixture was spread again in a thin layer of 0.5 to 1 cm over the seeds and neatly mulched with rice straw for 2-3 days to prevent the seed from direct exposure to sun, rain, birds etc. Table 1. Physico-chemical properties of the experimental soil Particulars Values Physical properties Mechanical analysis Sand (%) Silt (%) Clay (%) Textural class Clay loam Physico-chemical properties Soil ph Method of analysis Bouyoucos hydrometer (Piper,1966) Digital ph meter DI 707 (Jackson, 1967) Electrical conductivity (dsm-1) Digital EC meter (Jackson, 1967) Chemical properties Organic carbon (%) Wet digestion method (Walkley and Black, 1934) Available nitrogen (kg ha-1) Alkaline permanganate method (Subbaiah and Asija, 1956) Available phosphorus (kg ha- 1) Available potassium (kg ha-1) Olsen s extractant method (Olsen et al., 1954) Flame photometer (Jackson, 1973) Twelve days old seedlings were planted manually (one seedling hill-1) with a spacing of 25 cm x 25 cm. During transplanting, the seedlings were removed along with roots from nursery bed carefully and planted within 30 minutes after removing from nursery in the main field at very shallow depth. 2.3 Mechanized SRI The mat type nursery was prepared by laying plastic sheets of micron gauge on a raised puddled soil bed to a level of about 5 cm and followed by placing wooden frame of 50 cm x 19 cm x 2 cm size. The frame was filled with well-prepared soil. 3

4 Seeds were soaked for 24 hours and incubated in moist gunny bag for 24 hours. The sprouted seeds were broadcast uniformly on each 40 kg ha -1 and then covered with a thin layer of vermicompost (0.5 cm). Water was sprinkled three to four times in a day for six to seven days to keep the seed bed wet. One week after sowing, water was applied through the water channel until transplanting (Plate 3). To enhance the growth of seedling, 2% foliar spray of poorna (19:19:19 N:P: K) was given at 12 DAS. During transplanting (18 days old seedlings), the mats were lifted from the plastic sheets and placed directly in the trays of diesel engine drawn transplanted, which ran length wise of the field on the puddle and leveled land. The water level in the field was kept at less than 2 cm only to avoid floating of seedlings. The machine transplants seedlings from mat type nursery in eight rows in a single pass. The tray containing mat type nursery for 8 rows is moved sideways by a scroll shaft mechanism, which converts rotary motion received from the engine through belt pulley, gear and universal joint shaft into linear motion of a rod connected to the seedling tray having provision to reverse the direction of movement of tray after it reaches the extreme positions at ends. Fixed fork with knock out lever type planting fingers (cranking type) are moved by a four bar linkage to give the designed locus to the tip of the planting finger. 3. RESULTS AND DISCUSSION SRI gave significantly higher irrigation water productivity as compared to MSRI during both the years of study. SRI gave 7.01, 8.83 and 7.87 % higher irrigation water productivity than MSRI during 2013, 2014 and in pooled means, respectively. This was due to higher grain yield and comparatively lower irrigation water used in SRI. Similar findings were reported by Dass and Dhar (2014) and Kumar et al. (2014). SRI was superior in terms of growth parameters, yield attributes, yield, nutrient uptake, partial factor productivity and water productivity over MSRI. Days to panicle initiation and 50 % flowering were early by 5-6 days and 4-5 days, respectively in SRI as compared to MSRI. Irrigation maintained at saturation level produced significantly higher growth parameters, yield attributes, yield, N & K nutrient uptake and partial factor productivity which were comparable with irrigation at 3 DADPW. Irrigation at 3 DADPW superior with root growth characteristics, P uptake and lesser number of days taken for panicle initiation and 50 % flowering (Gopalakrishnan et al, 2013). The irrigation water productivity and water productivity were higher with irrigation at 5 DADPW. Application of N based on LCC registered significantly higher growth parameters, yield attributes, yield, nutrient uptake, P and K Pfp and water productivity which were comparable with STCR based nitrogen management practice. Panicle initiation and 50% flowering were early in LCC based N management practices as compared to other N management practices. Using intermittent irrigation, Thiyagarajan et al., (2002) reported a water saving of 50% over the traditional flooding without any adverse effect on grain yield and proved that SRI is not only seed saving but also water saving technology. The water saved for rice can be effectively used for increasing the area under rice or other irrigated dry crops in the cropping sequence for enhancing the system productivity. Hence, the better yields in SRI crop are due to its practices (young seedling, wider spacing, inter cultivation with weeder, saturation of soil without submergence and use of organics) taken together, create conditions in which beneficial for plant growth better tillering and yield attributes and yields. 4

5 Table.2. Grain, Straw yield and yield attributes as influenced by methods of crop establishment Grain yield t/ha straw yield t/ha Harvest index (%) 1000 grain panicle number of panicles / m 2 number of tillers / m 2 Treatments Kh-2015 M1 (MSRI) main plot M2 (SRI) SEM CD (0.05) NS 1.49 NS NS NS Table.3. Grain, Straw yield and yield attributes as influenced by irrigation scheduling Grain yield t/ha straw yield t/ha Harvest index (%) 1000 grain panicle number of panicles m 2 number of tillers / m 2 Treatments R14-15 I1 (saturation) I2(3 DADPW) I3 (5 DADPW) SEM CD (0.05) NS

6 Table.4. Grain, Straw yield and yield attributes as influenced by nutrient management Grain yield t/ha straw yield t/ha Harvest index (%) 1000 grain panicle number of number of panicles / m 2 tillers / m 2 Treatments R14-15 R14-15 N1 (RDN 100 %) sub sub plot N2 (25% organic and 75% inorganic) N3 (LCC) N4 (STCR) SEM CD (0.05) NS 1.50 NS Interaction NS 1.01 NS 0.81 NS 3.71 NS 1.61 NS 0.71 NS NS CV Mean Figure 1. Grain yield (t/ha) as influenced by crop establishment methods, irrigation scheduling and nitrogen management 6

7 Figure 2. Production and partitioning of dry matter in rice at 30, 60, 90 DAT and at harvest in to leaf, stem and panicle under MSRI and SRI of pooled means 4. CONCLUSIONS System of rice intensification (SRI) was superior in terms of growth parameters, root growth characteristics, yield attributes, yield, nutrient uptake, partial factor productivity and water productivity over mechanized system of rice intensification (MSRI). Days to panicle initiation and 50 % flowering were early by 5-6 days and 4-5 days, respectively in SRI as compared to MSRI. Irrigation maintained at saturation level produced significantly higher growth parameters, yield attributes, yield, N & K nutrient uptake and partial factor productivity which were comparable with irrigation at 3 DADPW. Irrigation at 3 DADPW superior with root growth characteristics, P uptake and lesser number of days taken for panicle initiation and 50 % flowering. The irrigation water productivity and water productivity were higher with irrigation at 5 DADPW which were at par with 3 DADPW. Application of N based on LCC registered higher growth parameters, root growth characteristics, yield attributes, yield, nutrient uptake, P and K partial factor productivity and water productivity which were at par with STCR based nitrogen management practice. Panicle initiation and 50 % flowering were early in LCC based nitrogen management practices as compared to other nitrogen management practices. The saving of the water to the extent of % accounts to nearly US$ /ha and US$ /ha during wet and dry seasons respectively and thereby reducing production cost especially under water scarce conditions. Further collaborative research studies are useful in SRI and its modifications to mitigate climate change effects (methane emissions), for enhancing resource conservation and for wide scale adoptability across the country. However, there is a need for a strong policy and suitable modifications to make SRI more adaptable and profitable to small and marginal farmers of the country. REFERENCES Awan, T.H., Ali, I., Safdar, M.E., Ahmad, M. and Akhtar, M.S Comparison of parachute, line and traditional rice transplanting methods at farmer s field in rice growing area. Pakistan Journal of Agricultural Sciences. 45 (4): 432:438. 7

8 Dass, A and Dhar, S Irrigation management for improving productivity nutrient uptake and water-use efficiency in system of rice intensification: a review. Annuals of Agricultural Research. 35(2) : Gopalakrishnan, S., Kumar, R.M., Humayun, P., Srinivas, V., Kumari, B.R., Vijayabharathi, R., Singh, A., Surekha, K., Ch. Padmavathi, Somashekar, N., Raghuveer Rao, P., Latha, P.C., Subba Rao, L.V., Babu, V.R., Viraktamath, B.C., Vinod Goud, V., Loganandhan, N., Biksham Gujja and Rupela Assessment of different methods of rice (Oryza sativa. L) cultivation affecting growth parameters, soil chemical, biological, and microbiological properties, water saving, and grain yield in rice rice system. Paddy and Water Environment Important Facts About Rice Production in India Jackson, H.L Soil Chemical Analysis. Prentice Hall of Inco. New York, USA Jackson, M.L., Soil Chemical Analysis, (Ed.). Prentice Hall of India Pvt. Ltd., New Delhi Kumar, R.M., Surekha, K., Padmavathi, Ch., Rao, L.V.S., Latha, P.C., Prasad, M.S., Babu, V.R., Ramprasad, A.S., Rupela, O.P., Goud, P.V., Raman, P.M., Somashekar, N., Ravichandran, S., Singh, S.P and Viraktamath, B.C Research experiences on System of Rice Intensification and future directions. Journal of Rice Research. 2 : Kumar, S., Singh, R.S and Kumar, K Yield and nutrient uptake of transplanted rice (Oryza sativa) with different moisture regimes and integrated nutrient supply. Current Advances in Agricultural Sciences. 6(1) : Laulanié, H Le système de riziculture intensive malgache. Tropicultura (Brussels) 11 : Olsen, S.R., Cole, C.V., Waterable, F.S and Dean, L.A Estimation of phosphorus in soils by extraction with sodium bicarbonate. United States Department of Agriculture Piper, C.S Soil and Plant Analysis. Academic press, New York Subbaiah, B.V and Asija, G.L A rapid procedure of estimation of available nitrogen in soils. Current Science. 65(7) : Swain, S.K., Nayak, B.R., Khanda, C.M and Dash, A.K Effect of establishment methods on yield and economics of rice (Oryza satavia L.). Madras Agricultural Journal. 100(10-12) : Thiyagarajan, T.M., Velu, V and Bindrabam, P.S Effect of SRI practice on rice in Tamil Nadu. IRRI Report. 26. Walkley, A and Black, C.A Estimation of organic carbon by chromic acid titration method. Soil Science. 37 : WWF-ICRISAT, More rice for people, more water for the planet. Africare, Oxfam America, WWF-ICRISAT Project, Hyderabad, India