0504 Scientific Opportunities and Challenges with the System of Rice Intensification
1. SCIENTIFIC OPPORTUNITIES AND CHALLENGES WITH THE SYSTEM OF RICE INTENSIFICATION (SRI) Norman Uphoff, CIIFAD Cornell University, USA Institute of Plant Nutrition, University of Bonn October 6, 2005
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3. Ms. Im Sarim, Cambodia, with rice plant grown from a single seed of traditional variety using SRI methods -- yield of 6.72 t/ha
25. 47.9% 34.7% “ Non-Flooding Rice Farming Technology in Irrigated Paddy Field” Dr. Tao Longxing, China National Rice Research Institute, 2004
26. Plant Physical Structure and Light Intensity Distribution at Heading Stage (Tao et al., CNRRI, 2002)
27. Change of Leaf Area Index (LAI) during growth cycle (Zheng et al., SAAS, 2003)
28. Roots’ Oxygenation Ability with SRI vs. Conventionally-Grown Rice Research done at Nanjing Agricultural University, Wuxianggeng-9 variety (Wang et al., 2002)
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30. Rice fields in Sri Lanka: same variety, same irrigation system, and same drought : conventional methods (left), SRI (right)
31. Rice in Vietnam: normal methods on right; SRI with close spacing in middle; SRI with recommended spacing on left
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38. MEASURED DIFFERENCES IN GRAIN QUALITY Characteristic SRI (3 spacings) Conventional Diff. Paper by Prof. Ma Jun, Sichuan Agricultural University, presented at 10th conference on Theory and Practice for High-Quality, High-Yielding Rice in China, Haerbin, 8/2004 + 17.5 38.87 - 39.99 41.81 - 50.84 Head milled rice (%) + 16.1 41.54 - 51.46 53.58 - 54.41 Milled rice outturn (%) - 65.7 6.74 - 7.17 1.02 - 4.04 General chalkiness (%) - 30.7 39.89 - 41.07 23.62 - 32.47 Chalky kernels (%)
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45. Rice in Tamil Nadu, India: normal crop is seen in foreground; SRI crop, behind it, resists lodging
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54. Increase in Finger Millet Yield with Guli Vidhana Method, as reported by Green Foundation, Bangalore Methods: Broadcast - Drill sowing - Close transplant - Guli Vidhana
55. SRI RAGI (FINGER MILLET), Rabi 2004-05 60 days after sowing – Varieties 762 and 708 VR 762 VR 708 10 15 21* *Age at which seedlings were transplanted from nursery Results of trials being being done by ANGRAU
65. Table 1. Summary of results from SRI vs. BMP evaluations in China and India, 2003-2004 * Chinese comparisons were made using hybrid rice varieties. 1.57 (27.7%) 7.23 5.66 100 trials (SRI and BMP trials each 0.1 ha) Tamil Nadu state 2.42 (33.8%) 8.73 6.31 1,525 trials (average 0.4 ha; range 0.1-1.6 ha) Andhra Pradesh state 3.31* (40.7%) 11.44* 8.13* 8 trials (0.2 ha each) Sichuan province 3.1* (35.2%) 11.9* 8.8* 16.8 ha of SRI rice with 2 hybrid varieties Zhejiang province SRI advantage (t ha -1 ) (% incr.) SRI ave. yield (t ha -1 ) BMP ave. yield (t ha -1 ) No. of on-farm comparison trials (area in parentheses) Province/state
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68. Roller-marker devised by Lakshmana Reddy, East Godavari, AP, India, to save time in transplanting operations; his yield in 2003-04 rabi season was 17.25 t/ha paddy (dry weight)
69. 4-row weeder designed by Gopal Swaminathan, Thanjavur, TN, India Aerate soil at same time that weeds are removed/incorporated
Slides for presentation to a seminar at the Institute of Plant Nutrition, University of Bonn, Germany, October 6, 2005, hosted by Prof. Mathias Becker.
SRI is not the best conceivable name for this management system, because ‘intensification’ has connoted greater use of external inputs. But it is the opposite of ‘extensive’ strategies that emphasize large scale, even if there are lower marginal returns to inputs, for the sake of greater profitability. SRI aims to get the greatest productivity on any scale, but it is most suitable for small-scale farmers, who can intensify their management of their rice crop, attending to the needs of the soil as well as of the plant.
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, Biratnagar, Nepal. This DADO is responsible for Morang district, but Uprety has taken leadership to extend SRI in other terai districts and now has gotten SRI being dissemination on a national basis. Farmers in Morang district in 2004 monsoon season had a doubling of yield, from 3.37 t/ha to 7.85 t/ha, with average time to maturity reduced by 15.1 days.
Picture of the SRI field of Dr. Gamini Batuwitage, who has started using SRI methods with Basmati rice, which has a much higher price in the market. He is not an agriculturalist, but took up growing SRI rice himself when he, as Sr. Asst. Secretary in the Ministry of Agriculture, encountered resistance from Sri Lankan rice scientists, who dismissed SRI without trying it. He wanted to be personally acquainted with SRI so that he could be a more effective and confident proponent. He is now executive director of the Gemi Diriya Foundation, set up with World Bank funding to promote poverty-reduction schemes among the poor in Sri Lanka, including SRI production.
Picture of SRI harvest at Sapu Research Station, provided by Dr. Mustapha Ceesay, former director of the station before he came to Cornell University to do MS and PhD in crop and soil sciences. He returned in 2000 and 2001 summers to carry out SRI trials on-station, with results of 5.4-8.3 t/ha. Nearby farmers who tried the methods were able to increase their yield by 100-200%.
This field was harvested in March 2004 with representatives from the Department of Agriculture present to measure the yield. Picture provided by George Rakotondrabe, Landscape Development Interventions project, which has worked with Association Tefy Saina in spreading the use of SRI to reduce land pressures on the remaining rainforest areas.
This story is related in Pere de Laulanie’s 1993 article in TROPICULTURA (Brussels), and still going on.
This picture was provided by Association Tefy Saina, showing Fr. de Laulanie the year before his death in 1995, at age 75.
These are the president and secretary of Association Tefy Saina, the NGO set up by Fr. de Laulanie, Sebastien, Justin and some other Malagasies in 1990 to promote SRI and rural development in Madagascar more generally.
SRI is often hard to accept because it does not depend on either of the two main strategies of the Green Revolution, not requiring any change in the rice variety used (genotype) or an increase in external inputs. The latter can be reduced.
This is the simplest description of what SRI entails. Transplanting is not necessary, as direct-seeding with the other practices gives good results also. The SRI principle is the if you transplant, the seedling should be young and care must be taken to cause minimum trauma to the roots.
SRI is a ‘designer’ innovation, practically tailored to the requirements of 21 st century agriculture, although this is not yet fully appreciated, as 20 th century thinking and practices are being perpetuated at the present time, not looking ahead to the constraints and factor endowments we must anticipate in the decades to come.
This is a brief summary of results; many other advantages as well such as often shorter time to maturity; higher milling outturn (10-15% more milled rice from SRI paddy rice); resistance to pests and diseases; resistance to abiotic stresses (drought, cold, storm damage), etc.
There are relatively few barriers to SRI adoption; most are mental. Little effort and thought has gone into improving technologies for production, handling and application of compost or mulch (biomass) to the soil. SRI makes these practices sufficiently profitable that it should elicit more research in this area and changes in farmer thinking and behavior.
SRI is often hard to accept because it does not depend on either of the two main strategies of the Green Revolution, not requiring any change in the rice variety used (genotype) or an increase in external inputs. The latter can be reduced.
Picture provided by Rajendra Uprety, District Agricultural Development Office, Biratnagar, serving Morang District, Nepal, September 2005. This plant was growing outside the field, so it has plenty of space to expand. About half the tillers are fertile.
Picture provided by Dr. A. Satyanarayana, at the time Director of Extension for Acharya N. G. Ranga Agricultural University (ANGRAU), the agricultural university for Andhra Pradesh state in India. Dr. Satyanarayana was a co-recipient with ICRISAT of the King Baudoin Award in 2002, the CGIAR’s highest award, as a plant breeder working on (drought-resistant) pulses. He has become the leader of SRI evaluation and dissemination efforts in Andhra Pradesh based on observed and measured results.
Picture provided by Dr. P. V. Satyanarayana, the plant breeder who developed this very popular variety, which also responds very well to SRI practices.
SRI is often hard to accept because it does not depend on either of the two main strategies of the Green Revolution, not requiring any change in the rice variety used (genotype) or an increase in external inputs. The latter can be reduced.
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.
Rice plants at 80 days, started in same nursery, but SRI plant on left transplanted at 9 days into an SRI environment. Picture courtesy of Dr. Rena Perez, from farm of Luis Romero.
These last slides get into an area of SRI explanation that is more tentative, but probably more important for highest SRI yields. There is a lot of country-to-country variation in SRI results, and also within countries, much larger variations than can be explained by differences in practices or by differences in soil chemical and physical properties. We cite an observation by S. K. DeDatta in his well-known text on rice. We add our own emphasis to underscore our conclusion that there needs to be much more consideration of soil microbes and their contributions to rice yield. There is, however, little research on this subject, so DeDatta devoted very few pages to this compared to genetic, soil and other factors.
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.
This figure is based on research findings from the China National Rice Research Institute, reported at the Sanya conference in April 2002 and published in the conference proceedings. Two different rice varieties were used (top and bottom rows) with SRI and conventional (CK) methods (left and right columns). The second variety responded more positively to the SRI methods in terms of leaf area and dry matter as measured at different elevations, but there was a very obvious difference in the phenotypes produced from the first variety's genome by changing cultivation methods from conventional to SRI. Both leaf area and dry matter were significantly increased by using SRI methods.
Figure from research on SRI done by the Crop Research Institute of the Sichuan Academy of Agricultural Sciences, comparing leaf area of SRI rice with conventional rice, same variety and otherwise same growing conditions.
Figure from a report by Nanjing Agricultural University researchers to the 2002 Sanya conference, and reproduced from the conference proceedings. It shows that the oxygenation ability of rice roots growing under SRI conditions are about double the ability, throughout the growth cycle, compared to the same variety grown under conventional conditions. At maturity, the SRI roots have still almost 3x the oxygenation ability of conventionally grown rice plants.
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.
Picture provided by Dr. Max Whitten, former head of plant pathology in ACIAR, Australia, now working with FAO and FFS crop protection programme as consultant.
Data reported by District Agricultural Development Office, Morang District, Biratnagar, Nepal (Rajendra Uprety); AP data from Dr. A. Satyanarayana, at the time Director of Extension, ANGRAU, for state of Andhra Pradesh, from 2003-2004 season; Cambodia data from Dr. Yang Saing Koma, executive director, CEDAC.
This book should be read by anyone and everyone in the agricultural sciences.
The theory of trophobiosis was proposed in Dr. Chaboussou’s 1985 book, but has been largely ignored in the agricultural sciences, being taken seriously only in Brazil, where it has become widely accepted.
Dr. Chaboussou’s analysis and conclusions are based on research published in the mainstream, peer-reviewed literature since the 1930s. The 2004 edition is a translation of his 1985 book, so it does not have more recent references, but the theory makes sense of what has been observed and written about in terms of crop pests and diseases for many years, integrating these observations and articles into one coherent explanation, across different kinds of pests and pathogens.
This was first reported in Sri Lanka, where rice millers in the Mahaweli System H scheme were coming to farmers who had SRI crops standing in the field and offering to pay 10% more per bushel for their SRI paddy. This suggested that the outturn had to be more than 10% higher than with ‘normal’ paddy because millers do not offer higher prices to farmers on altruistic grounds.
These data from Prof. Ma Jun presented at the Haerbin conference confirmed what had been reported more anecdotally for several years. The data also covered rice quality assessed in terms of chalkiness (amylose content). The data showed SRI rice grains (from three different spacings within the SRI range) to be clearly superior in two major respects to conventionally-grown grains (two spacings). A reduction in chalkiness makes the rice more palatable. An increase in outturn is a ‘bonus’ on top of the higher yields of paddy (unmilled) rice that farmers get with SRI methods. We have seen this kind of improvement in outturn rates in Cuba, India and Sri Lanka, about 15%. More research on other aspects of SRI grain quality should be done, including nutritional content.
Dr. Anischan Gani at the Sukamandi rice research station of the Indonesian Agency for Agricultural Research and Development did measurements of illumination within the canopy of rice plants growing with SRI spacing and with normal spacing. The lower third of the canopy with normal spacing did not have enough illumination to support photosynthesis, which made these leaves dependent on the photosynthesis of other leaves, rather than contributing net photosynthate to the plant’s metabolism. Abha Mishra at Asian Institute of Technology, Bangkok, has reviewed literature on this and reports that it is the lower leaves that provide most photosynthate to the root systems – if they have any surplus.
These relationships are well known, but are not often reported in the literature. Two instances are cited here.
DeDatta in three different places in his authoritative book on rice says that rice plants perform better under submerged conditions. Unfortunately, this is not correct, and he acknowledges this now. There are few studies of rice roots. The Kirk and Bouldin article is one of the few.
These pictures are from an article by Michel Puard (1986) in the French journal on tropical agriculture. On left are cross sections of root from an ‘upland’ variety, and on the right, cross-sections from the root of an ‘irrigated’ variety. Top left is under upland conditions, and bottom left from flooded conditions; top right is under flooded conditions (note that the ‘irrigated’ variety has more degeneration of its cortex to form larger and presumably better-functioning aerenchyma, to permit more oxygen to circulate within the root tissues), and lower right is under upland conditions. The ‘irrigated variety’ when not subjected to hypoxic, submerged conditions, has an undegenerated cortex, presumably a more ‘normal’ condition, than when it is growing under continuously flooded conditions.
Again, citing literature that is well-accepted.
Effects of silicon uptake are not discussed in the literature, as far as I know. We see in SRI phenotypes much stronger tillers and also sturdier leaves. Farmers report that in SRI fields, they cannot walk through with short pants without getting cuts on their legs (a minor inconvenience compared with the benefit of higher yield) whereas there is no problem walking through ‘normal’ (N-fertilized) rice.
Picture provided by Dr. T. M. Thiyagarajan, dean of TNAU college of agriculture at Killikulam, Tamil Nadu, India.
This is one of the most interesting aspects of SRI, based in plant physiology that is not widely known because Katayama’s work is not known much outside of the Japanese-reading/speaking world. Outside this phenomenon is addressed more crudely in terms of degree-days and leaf age, serviceable concepts that are not as well-grounded in plant physiology as the concept of phyllochron, which applies to all gramineae species.
Diagram developed by Fr. de Laulanie after learning about the theory of phyllochrons (T. Katayama, 1951) as reported in book on rice by Didier Moreau, published by GRET, Paris, 1986)
This is the chart that Fr. de Laulanie work out once he knew about Katayama’s concept of phyllochrons from the book by Didier Moreau (GRET, 1986).
This is a chart that I have worked out from reading Nemoto et al., 1995, the only article on rice phyllochrons in a volume of CROP SCIENCE (35:1) devoted to phyllochrons (with papers from a symposium organized by USDA scientists who work on wheat). Phyllochrons is a concept now known among wheat scientists, but little among (non-Japanese-reading) rice scientists. Forage scientists in Australia also know about and are working with the concept of phyllochrons in grasses, as can be seen from a search on the Web. Rice growing will be more successful to the extent that the factors on the left can be increased and those on the right can be avoided. This will shorten phyllochron length and lead to more phyllochrons of growth being completed before panicle initiation (PI), which means that rice plants will have more tillers – and more roots! – for the next phase of reproduction once vegetative growth has stopped.
This is a ‘bonus.’ CIIFAD with partners in Cambodia, Madagascar and Sri Lanka put in a proposal to the UNEP-UNDP-IUCN SEED Initiative, and this was selected as one of the five winning proposals from more than 260 considered. It aims to promote the production of indigenous rice varieties by organic means so that the resulting rice can be sold for a higher price, making the conservation of rice biodiversity more profitable. SRI methods also by reducing agrochemical use and irrigated rice production’s demand for water also contributes to healthier ecosystems, esp. aquatic ecosystems that are in competition with rice production for water supply. WWF’s Aquatic Ecosystems Program, based at ICRISAT in India, has been funding evaluations of SRI in Andhra Pradesh, to determine whether there is enough water saving to justify WWF’s promotion of SRI for environmental protection purposes.
The Paraboowa Farmers Association has a dozen ‘wild rice’ varieties that it can grow for marketing or for export. The rice is grown ‘organically’ so can get a premium price in overseas markets. 17 tons have been exported to Italy already. The farmers want to preserve these varieties for future generations, and SRI enables them to do this.
This is something that farmers are undertaking – to use SRI ideas for other crops.
The Green Foundation, an NGO in Bangalore, India, working with poor and marginal populations, particularly tribal women, has come across and documented the Guli Vidhana method of cultivating ragi (finger millet). This was developed by some farmers, but Green Foundation, which is promoting SRI in Karnataka State, saw the similarities in concept – and in results – with SRI, and points this out in its educational poster for Guli Vidhana method, which is tripling yield for poor households that desperately need more food.
This is a drawing from the poster that the Green Foundation has prepared to promote the Guli Vidhana method among poor households in Karnataka State, who have no access to irrigation, only rainfed land.
These pictures of finger millet roots, all at 60 days of age, with different dates (ages) of transplanting, confirm the observations with SRI that using younger seedlings for transplanting will result in more vigorous root (and shoot) growth. Pictures from staff of the Acharya N. G. Ranga Agricultural University in Hyderabad, India, the state agricultural university for Andhra Pradesh.
This is a picture sent by Thadeusz Niesiobedzki in Poland, of his winter wheat crop that is being grown with single seedlings, wide spacing, use of organic matter, etc. approximating SRI. He hit upon these practices by accident (a long story) and also discovered the SRI internet web page, and saw the similarities between his practices and SRI, thereafter contacting Cornell by email to open up dialogue.
This method has been developed by Prabhakar Reddy, one of the first SRI farmers in Andhra Pradesh state, and is being monitored and documented by Dr. Shashi Bhushan, ANGRAU faculty member. Reddy was explicitly adapting his SRI experience to sugar cane production, with similarly large increases in production from reduced planting material.
The upland rice results are from trials by BIND (Broader Initiatives for Negros Development, in Negros Occidental); the Madagascar results were reported in CIIFAD Annual Report 1999-2001. The cotton and vegetable results are reported by Gopal Swaminathan, a farmer in Kadiramangalam in the Cauvery Delta of Tamil Nadu. He is one of many experimenting farmers who are taking SRI ideas into new areas.
SRI defies usual logic – that to get more, you have to invest more. But “less” can produce “more,” for a number of different, but reinforcing reasons, well grounded in the scientific literature. USDA research by Kumar and associates (Proceedings of the National Academy of Sciences, US, 2004) shows how changed growing conditions in the root zone affects the expression of genes in leaf tissue cells, affecting senescence and disease resistance. This research gives clues for explaining how SRI practices produce different phenotypes.
We are learning more about the many services the soil organisms provide to produce healthier, more productive plants. This is a listing of the most important identified so far. On the last point, see book by Frankenburger and Arshad (1995) on microbial (aerobic bacterial and fungal) production of auxins, cytokinins, etc. that stimulate root growth and have other benefits, such as ISR.
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 "indicator species" 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.
Picture provided by Dr. Zhu Defeng, China National Rice Research Institute, September 2004.
SRI farmer in Chibal village, Srey Santhor district, Kampong Cham province, Cambodia
Picture provided by Dr. Peng Jiming, associate director of the China National Hybrid Rice Research and Development Center, Changsha, from trials that CNHRDDC is doing in the West African country of Guinea growing its hybrid rice varieties with SRI methods.
These data were provided by, respectively, the China National Rice Research Institute, Hangzhou, Zhejiang Province, China; the Crop Research Institute of the Sichuan Academy of Agricultural Sciences, Chengdu, Sichuan Province, China; the Acharya N. G. Ranga Agricultural University (ANGRAU), Hyderabad, Andhra Pradesh State, India; and the Tamil Nadu Agricultural University (TNAU) College of Agriculture, Killikulam, Tamil Nadu State, India. The data from the on-going evaluation of SRI by these institutions.
SRI experience suggests that the agricultural sector can achieve great gains in productivity by capitalizing upon biological potentials. Conventional biotechnology, which is an extension of the Green Revolution paradigm, will not give as great benefits as biotechnology that is agroecologically-oriented, taking into account the interactions of plants with microbial symbionts.
Tefy Saina is more comfortable communicating in French language, though it can handle English. CIIFAD has worldwide contacts on SRI through the internet.
This was developed in 2003 by Mr. L. Reddy, to replace the use of strings and sticks to mark lines for planting, or the use of a wooden “rake” that could mark lines when pulled across the paddy in two directions. This implement, which can be built for any spacing desired, enables farmers, after it is pulled across the paddy in one direction, to plant SRI seedlings in a 25x250 cm square pattern. It saves as lot of labor time for transplanting because only one pass is needed across the field, and this is wider than a rake could be. Even wider ones have been built. Mr. Reddy is a very innovative and successful SRI farmer, with a superb yield last rabi season, measured and reported by the Department of Extension in Andhra Pradesh.
Mr. Gopal Swaminthan, an educated farmer in the Cauvery Delta of Tamil Nadu, India, built this weeder which can cultivate four rows at a time, removing weeds and aerating the soil, cutting labor time for this operation by half or more. He has also devised an innovative system for crop establishment, suited to hot climates, called the Kadiramangalam system, described on our SRI home page (http://ciifad.cornell.edu/sri/)
Mr. Subasinghe Ariyaratna has 2 ha and thus found it difficult to manage the weeding of his SRI field himself. So he designed and built this weeder which he says enables him to weed his field in one day’s work. The cost of construction, with a Chinese motor attached, was $800. This could be lowered if the weeder were mass produced.
Built by Luis Romero, one of the most successful SRI farmers in Cuba, to plant germinated seeds at 40x40 cm spacing. The seeds are put in the respective bins and dropped at the bins rotate. For his field, Luis found that 40x40 cm was too wide, because of weed problems. He has built one for 30x30 cm now. His neighbor built a seeder with 12 bins, four times as wide, that can be pulled by oxen to further save labor. The important thing to know is that farmers are working on their own ways to reduce SRI labor requirements because they see the benefits of wide spacing, aerated soil, etc.
This is Liu Zhibin with a plot that was harvested just before my visit, with an official certificate for a yield of 13.4 t/ha. I was most interested in his experimentation with no-till methods and SRI.
In Heilongjiong province of China, seedlings need to be started in heated greenhouses when there is still snow on the ground. Dr. Jin Xueyong at Northeast Agricultural University in Haerbin has developed the 3-S system for growing rice in cold climates that is about 80% the same as SRI. It must use older seedlings (45-days) because of the lower temperatures, but it uses single seedlings, wide spacing, reduced water, more organic matter, etc.
Two fields of rice grown with normal methods on the left and the 3-S system on the right. The phenotypical differences are evident, much as seen with SRI. Prof. Jin is in center with blue shirt and white cap.
This is a SRI rice nursery in Sri Lanka, showing one way (but only one of many ways) to grow young seedlings. The soil in this raised bed was a mixture of one-third soil, one-third compost, and one-third chicken manure. (The flooding around it is because the surrounding field is being readied for transplanting; normally there would not be so much water standing around the nursery.)
Here the seedlings are being removed. We would recommend that they be lifted with a trowel, to have minimum disturbance of the roots, but these seedlings are so vigorous that this manual method is successful. This farmer has found that his seedlings, when transplanted with two leaves at time of transplanting, already put out a third leave the next day after transplanting, indicating that there was no transplant 'shock.'
Here the field is being 'marked' for transplanting with a simple wooden 'rake.' If the soil is too wet, these lines will not remain long enough for transplanting. There are drains within the field to carry excess water away from the root zone.
Here are seedlings being removed from a clump for transplanting. Note that the yellow color comes from the sunlight reflecting off the plant. The plant's color is a rich green, indicating no N deficiency.
Here the seedlings are being set into the soil, very shallow (only 1-2 cm deep). The transplanted seedlings are barely visible at the intersections of the lines. This operation proceeds very quickly once the transplanters have gained some skill and confidence in the method. As noted already, these seedling set out with two leaves can already have a third leaf by the next day.
Picture provided by Gamini Batuwitage, at the time Sr. Asst. Secretary of Agriculture, Sri Lanka, of SRI field that yielded 13 t/ha in 2000, the first year SRI was used in that country. Such performance got SRI started there..