Picture provided by Dr. Rena Perez. These two rice plants are ‘twins’ in that they were planted on the same day in the same nursery from the same seed bag. The one on the right was taken out at 9 days and transplanted into an SRI environment. The one on the left was kept in the flooded nursery until its 52 nd day, when it was taken out for transplanting (in Cuba, transplanting of commonly done between 50 and 55 DAP). The difference in root growth and tillering (5 vs. 42) is spectacular. We think this difference is at least in part attributable to the contributions of soil microorganisms producing phytohormones in the rhizosphere that benefit plant growth and performance.
Picture provided by Dr. Koma Yang Saing, director, Cambodian Center for the Study and Development of Agriculture (CEDAC), September 2004. Dr. Koma himself tried SRI methods in 1999, and once satisfied that they worked, got 28 farmers in 2000 to try them. From there the numbers have increased each year, to 400, then 2100, then 9100, then almost 17,000. Over 50,000 farmers are expecting to be using SRI in 2005. Ms. Sarim previously produced 2-3 t/ha on her field. In 2004, some parts of this field reached a yield of 11 t/ha, where the soil was most ‘biologized’ from SRI practices.
Picture provided by Rajendra Uprety, District Agricultural Development Office, Morang District, Nepal. Again, this is a single SRI plant grown from a single seed.
This is the most simple description of what SRI entails. Transplanting is not necessary since direct seeding, with the other SRI practices, also produces similarly good results. The principle of SRI is that if transplanting is done , very young seedling should be used, and there should be little or no trauma to the young plant roots. These are often ‘abused’ in transplanting process, being allowed to dry out (desiccate), or are knocked to remove soil, etc.
This picture from Sri Lanka shows two fields having the same soil, climate and irrigation access, during a drought period. On the left, the rice grown with conventional practices, with continuous flooding from the time of transplanting, has a shallower root system that cannot withstand water stress. On the right, SRI rice receiving less water during its growth has deeper rooting, and thus it can continue to thrive during the drought. Farmers in Sri Lanka are coming to accept SRI in part because it reduces their risk of crop failure during drought.
Figures from a paper presented by Dr. Tao to international rice conference organized by the China National Rice Research Institute for the International Year of Rice and World Food Day, held in Hangzhou, October 15-17, 2004. Dr. Tao has been doing research on SRI since 2001 to evaluate its effects in physiological terms.
These data were reported in Prof. Robert Randriamiharisoa's paper in the Sanya conference proceedings. They give the first direct evidence to support our thinking about the contribution of soil microbes to the super-yields achieved with SRI methods. The bacterium Azospirillum was studied as an &quot;indicator species&quot; presumably reflecting overall levels of microbial populations and activity in and around the plant roots. Somewhat surprisingly, there was no significant difference in Azospirillum populations in the rhizosphere. But there were huge differences in the counts of Azospirillum in the roots themselves according to soil types (clay vs. loam) and cultivation practices (traditional vs. SRI) and nutrient amendments (none vs. NPK vs. compost). NPK amendments with SRI produce very good results, a yield on clay soil five times higher than traditional methods with no amendments. But compost used with SRI gives a six times higher yield. The NPK increases Azospirillum (and other) populations, but most/much of the N that produced a 9 t/ha yield is coming from inorganic sources compared to the higher 10.5 t/ha yield with compost that depends entirely on organic N. On poorer soil, SRI methods do not have much effect, but when enriched with compost, even this poor soil can give a huge increase in production, attributable to the largest of the increases in microbial activity in the roots. At least, this is how we interpret these findings. Similar research should be repeated many times, with different soils, varieties and climates. We consider these findings significant because they mirror results we have seen in other carefully measured SRI results in Madagascar. Tragically, Prof. Randriamiharisoa, who initiated this work, passed away in August, 2004, so we will no longer have his acute intelligence and probing mind to advance these frontiers of knowledge.
0950 Considering plant-microbial interactions suggested by the System of Rice Intensification
Considering plant-microbial interactions suggested by the System of Rice Intensification Zhejiang University, January 15, 2009 Norman Uphoff, CIIFAD, Cornell University, USA
SRI: a methodology developed for raising rice yields in Madagascar <ul><li>Overview of SRI – can see the positive effects from altering rice mgmt practices </li></ul><ul><li>Evidence of the phenotypical effects of SRI practices (also epigenetic effects ?) </li></ul><ul><li>Data suggesting positive contributions of soil microbial populations to rice yield </li></ul><ul><li>SRI changes in soil microbial populations </li></ul><ul><li>Contributions to rice performance from endophytic symbiotic microbes </li></ul>
CUBA: farmer with two plants of same variety (VN 2084) and same age (52 DAP)
SRI does not rely on either (a) the introduction of improved varieties or (b) the application of external inputs <ul><li>SRI changes the ways that rice plants, soil, water and nutrients are managed to get more productive PHENOTYPES from any and all rice GENOTYPES </li></ul><ul><li>Changes in plant morphology – numbers of tillers, root system growth, leaf area, angle of tillers, etc. </li></ul><ul><li>Changes in plant physiology – water-use efficiency, root exudation, rates of photosynthesis, delayed senescence, etc. </li></ul><ul><li>Indications of EPIGENETIC changes to be explored – contribution from plant-microbial interactions ? </li></ul>
CAMBODIA: Rice plant grown from single seed in Takeo province
NEPAL: Single rice plant grown with SRI methods, Morang district
IRAN: SRI roots and normal (flooded) roots: note difference in color as well as size
IRAQ: Comparison trials at Al-Mishkhab Rice Research Station, Najaf
‘ Rice Aplenty in Aceh’ (Indonesia) CARITAS NEWS Spring 2009 SRI methods were introduced in Aceh in 2005 by CARITAS Australia after tsunami had devastated the area – new methods raised local rice yields from 2 t/ha to 8.5 t/ha: “Using less rice seed, less water and organic compost, farmers in Aceh have quadrupled their crop production.”
2009 Report from Aga Khan Foundation program in Baghlan Province,Afghanistan 2008: 6 farmers got SRI yields of 10.1 t/ha vs. 5.4 t/ha regular 2009: 42 farmers got SRI yields of 9.3 t/ha vs. 5.6 t/ha regular 2 nd -year SRI farmers got 13.3 t/ha vs. 5.6 t/ha 1 st -year SRI farmers got 8.7 t/ha vs. 5.5 t/ha
AFGHANISTAN : SRI field in Baghlan Province, supported by Aga Khan Foundation Natural Resource Management program
SRI plant with 133 tillers @ 72 days after transplanting 11.56 t/ha
BHUTAN: Report on SRI in Deorali Geog, 2009 Sangay Dorji, Jr. Extension Agent, Deorali Georg, Dagana SRI @ 25x25cm 9.5 t/ha SRI random spacing 6.0 t/ha SRI @ 30x30cm 10.0 t/ha Standard practice 3.6 t/ha
Comparison of SRI and usual rice plants in INDONESIA Miyatty Jannah, Crawuk village, Ngawi, E. Java
INDONESIA: Sampoerna CSR Program, Malang, E. Java, 2009 Single SRI rice plant Variety: Ciherang No. of fertile tillers: 223
Extensions of SRI to Other Crops: Uttarakhand / Himachal Pradesh, India Rajma (kidney beans) Manduwa (millet) Crop No. of Farmers Area (ha) Grain Yield (t/ha) % Incr. 2006 Conv. SRI Rajma 5 0.4 1.4 2.0 43 Manduwa 5 0.4 1.8 2.4 33 Wheat Research Farm 5.0 1.6 2.2 38 2007 Rajma 113 2.26 1.8 3.0 67 Manduwa 43 0.8 1.5 2.4 60 Wheat (Irrig.) 25 0.23 2.2 4.3 95 Wheat (Unirrig.) 25 0.09 1.6 2.6 63
<ul><li>ICRISAT-WWF Sugarcane Initiative : at least 20% more cane yield, with: </li></ul><ul><li>30% reduction in water, and </li></ul><ul><li>25% reduction in chemical inputs </li></ul><ul><li>“ The inspiration for putting </li></ul><ul><li>this package together is </li></ul><ul><li>from the successful </li></ul><ul><li>approach of SRI – System </li></ul><ul><li>of Rice Intensification.” </li></ul>
SRI Involves Only Changes in Practices <ul><li>Transplant young seedlings to preserve their growth potential -- but DIRECT SEEDING is now an option </li></ul><ul><li>Avoid trauma to the roots -- transplant quickly and shallow, not inverting root tips which halts growth </li></ul><ul><li>Give plants wider spacing -- one plant per hill and in square pattern to achieve “edge effect” everywhere </li></ul><ul><li>Keep paddy soil moist but unflooded -- soil should be mostly aerobic -- not continuously saturated </li></ul><ul><li>Actively aerate the soil as much as possible </li></ul><ul><li>Enhance soil organic matter as much as possible </li></ul><ul><li>First 3 practices stimulate plant growth , while the latter 3 practices enhance the growth and health of plants’ ROOTS and of soil BIOTA </li></ul>
Evidence of Phenotypical Effects of SRI Practices
SRI LANKA: same rice variety, same irrigation system & same drought -- left, conventional methods; right, SRI
VIETNAM: D ông Trù village, Hanoi province, after typhoon
India: Meteorological and yield data from ANGRAU IPM evaluation, Andhra Pradesh, 2006 * Low yield was due to cold injury for plants (see above) *Sudden drop in min. temp. during 16–21 Dec. (9.2-9.8 o C for 5 days) Period Mean max. temp. 0 C Mean min. temp. 0 C No. of sunshine hrs 1 – 15 Nov 27.7 19.2 4.9 16–30 Nov 29.6 17.9 7.5 1 – 15 Dec 29.1 14.6 8.6 16–31 Dec 28.1 12.2 * 8.6 Season Normal (t/ha) SRI (t/ha) Rabi 2005-06 2.25 3.47 Kharif 2006 0.21* 4.16
Nepal: Crop duration (from seed to seed) of rice varieties with SRI vs. conventional methods – average no. of days: 125 vs. 141 Varieties Conventional duration SRI duration Difference Bansdhan/Kanchhi 145 127 (117-144) 18 (28-11) Mansuli 155 136 (126-146) 19 (29- 9) Swarna 155 139 (126-150) 16 (29- 5) Sugandha 120 106 (98-112) 14 (22- 8) Radha 12 155 138 (125-144) 17 (30-11) Barse 3017 135 118 17 Hardinath 1 120 107 (98-112) 13 (22- 8) Barse 2014 135 127 (116-125) 8 (19-10)
47.9% 34.7% Non-Flooding Rice Farming Technology in Irrigated Paddy Field Dr. Tao Longxing, China National Rice Research Institute, 2004
China National Rice Research Institute: Factorial trials over two years, 2004/2005 using two super-hybrid varieties with the aim of breaking the ‘plateau’ limiting yields <ul><li>Standard Rice Mgmt </li></ul><ul><li>30-day seedlings </li></ul><ul><li>20x20 cm spacing </li></ul><ul><li>Continuous flooding </li></ul><ul><li>Fertilization: </li></ul><ul><ul><li>100% chemical </li></ul></ul><ul><li>New Rice Mgmt (SRI) </li></ul><ul><li>20-day seedlings </li></ul><ul><li>30x30 cm spacing </li></ul><ul><li>Alternate wetting and drying (AWD) </li></ul><ul><li>Fertilization: </li></ul><ul><ul><li>50% chemical, </li></ul></ul><ul><ul><li>50% organic </li></ul></ul>
Average super-rice yields (kg/ha) with new rice management (SRI) vs.standard rice management at different plant densities ha -1
AN ASSESSMENT OF PHYSIOLOGICAL EFFECTS OF THE SYSTEM OF RICE INTENSIFICATION (SRI) COMPARED WITH RECOMMENDED RICE CULTIVATION PRACTICES IN INDIA A.K. Thakur, N. Uphoff, E. Antony Experimental Agriculture , 46(1), 77-98 (2010) Water-use efficiency is reflected in the ratio of photosynthesis to transpiration For the loss of 1 millimol of water by transpiration, In SRI plants, 3.6 millimols of CO 2 are fixed In RMP plants, 1.6 millimols of CO 2 are fixed
Comparison of chlorophyll content, transpiration rate, net photosynthetic rate, stomatal conductance, and internal CO 2 concentration in SRI and RMP Standard deviations are given in parentheses (n = 15). Parameters Cultivation method SRI RMP LSD .05 Total chlorophyll (mg g -1 FW) 3.37 (0.17) 2.58 (0.21) 0.11 Chlorophyll a/b ratio 2.32 (0.28) 1.90 (0.37) 0.29 Transpiration (m mol m -2 s -1 ) 6.41 (0.43) 7.59 (0.33) 0.27 Net photosynthetic rate (μ mol m -2 s -1 ) 23.15 (3.17) 12.23 (2.02) 1.64 Stomatal conductance (m mol m -2 s -1 ) 422.73 (34.35) 493.93 (35.93) 30.12 Internal CO 2 concentration (ppm) 292.6 (16.64) 347.0 (19.74) 11.1
Data from Madagascar Suggested that Contributions of Soil Microbial Populations & Plant-Microbial Interactions Could Explain SRI Effects
Effects of Active Soil Aeration with Mechanical Weeder Mechanical Weedings (N) Yield (t ha -1 ) MADAGASCAR: 1997-98 main season -- Ambatovaky (N=76) None 2 5.97 One 8 7.72 Two 27 7.37 Three 24 9.12 Four 15 11.77 NEPAL: 2006 monsoon season – Morang district (N=412) One 32 5.16 (3.6 – 7.6) Two 366 5.87 (3.5 – 11.0) Three 14 7.87 (5.85 – 10.4)
We See that SRI Management Practices Can Modify Soil Microbial Populations
Microbial populations in rice rhizosphere Tamil Nadu Agricultural University research T. M. Thiyagarajan, WRRC presentation, Tsukuba, Japan, 2004 Microorganisms Conventional SRI Total bacteria 88 x 10 6 105 x 10 6 Azospirillum 8 x 10 5 31 x 10 5 Azotobacter 39 x 10 3 66 x 10 3 Phosphobacteria 33 x 10 3 59 x 10 3
Total bacteria Total diazotrophs Microbial populations in rhizosphere soil in rice crop under different management at active tillering, panicle initiation and flowering (SRI = yellow; conventional = red) [units are √ transformed values of population/gram of dry soil] Phosphobacteria Azotobacter
Dehydrogenase activity (μg TPF) Urease activity (μg NH 4 -N)) Microbial activities in rhizosphere soil in rice crop under different management (SRI = yellow; conventional = red) at active tillering, panicle initiation and flowering stages [units are √ transformed values of population/gram of dry soil per 24 h] Acid phosphate activity (μg p-Nitrophenol) Nitrogenase activity (nano mol C 2 H 4 )
Total microbes and numbers of beneficial microbes (CFU g -1 ) under conventional and SRI cultivation methods, Tanjung Sari, Bogor, Indonesia, Feb-Aug 2009 (Iswandi et al., 2009) Cultivation method and fertilization Total microbes (x10 5 ) Azoto-bacter (x10 3 ) Azospi- rillum (x10 3 ) P-solubilizing bacteria (x10 4 ) Conventional crop mgmt with NPK 2.3a 1.9a 0.9a 3.3a Inorganic SRI (NPK fertilizer) 2.7a 2.2a 1.7ab 4.0a Organic SRI (compost) 3.8b 3.7b 2.8bc 5.9b Inorganic SRI + biofertilizer 4.8c 4.4b 3.3c 6.4b
Endophytic Symbiotic Microbes -- both Bacteria and Fungi – Can Contribute to Rice Plant Productivity Not O nly in the Rhizosphere These reports may or may not apply to SRI, which is still really ‘a work in progress’
Ascending Migration of Endophytic Rhizobia, from Roots and Leaves, inside Rice Plants and Assessment of Benefits to Rice Growth Physiology Feng Chi et al., Applied and Envir. Microbiology 71 (2005), 7271-7278 Rhizo-bium test strain Total plant root volume/ pot (cm 3 ) Shoot dry weight/ pot (g) Net photo-synthetic rate (μmol -2 s -1 ) Water utilization efficiency Area (cm 2 ) of flag leaf Grain yield/ pot (g) Ac-ORS571 210 ± 36 A 63 ± 2 A 16.42 ± 1.39 A 3.62 ± 0.17 BC 17.64 ± 4.94 ABC 86 ± 5 A SM-1021 180 ± 26 A 67 ± 5 A 14.99 ± 1.64 B 4.02 ± 0.19 AB 20.03 ± 3.92 A 86 ± 4 A SM-1002 168 ± 8 AB 52 ± 4 BC 13.70 ± 0.73 B 4.15 ± 0.32 A 19.58 ± 4.47 AB 61 ± 4 B R1-2370 175 ± 23 A 61 ± 8 AB 13.85 ± 0.38 B 3.36 ± 0.41 C 18.98 ± 4.49 AB 64 ± 9 B Mh-93 193 ± 16 A 67 ± 4 A 13.86 ± 0.76 B 3.18 ± 0.25 CD 16.79 ± 3.43 BC 77 ± 5 A Control 130 ± 10 B 47 ± 6 C 10.23 ± 1.03 C 2.77 ± 0.69 D 15.24 ± 4.0 C 51 ± 4 C
Data are based on the average linear root and shoot growth of three symbiotic (dashed line) and three nonsymbiotic (solid line) plants. Arrows indicate the times when root hair development started. Ratio of root and shoot growth in symbiotic and nonsymbiotic rice plants -- symbiotic plant seeds were inoculated with Fusarium culmorum Russell J. Rodriguez et al., ‘Symbiotic regulation of plant growth, development and reproduction,’ Communicative and Integrative Biology , 2:3 (2009).
Growth of nonsymbiotic (on left) and symbiotic (on right) rice seedlings. On growth of endophyte (F. culmorum) and plant inoculation procedures, see Rodriguez et al., Communicative and Integrative Biology , 2:3 (2009).
<ul><li>SRI is pointing the way toward an emerging paradigm shift in the agricultural sciences: </li></ul><ul><li>Less genocentric and more fundamentally biocentric </li></ul><ul><li>More interest in epigenetics </li></ul><ul><li>Re-focus biotechnology and bioengineering to capitalize on benefits of biodiversity and ecological dynamics </li></ul><ul><li>Less chemical-dependent and more energy-efficient </li></ul><ul><li>More oriented to health of humans and the environment </li></ul><ul><li>Intensification of production </li></ul><ul><li>Focus on greater factor productivity and sustainability </li></ul>