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Chapters 4 through 11 traced the emergence of a shared understanding about why the methods of rice production assembled by Fr. Laulanié in Madagascar more than 30 years ago and called the System of Rice Intensification (SRI) are effective. These practices and ideas amount to a paradigm shift for the production of more than just rice (Chapter 12). SRI and its extension into SCI for other crops underscore the importance of modifying management factors that improve the environments in which crop plants grow, rather than relying primarily on the modification of plants’ genes to raise production.[1]

This does not mean that genetic potentials are unimportant. Indeed, SRI success derives from evoking these potentials more fully. It does mean, however, that new varieties are not necessarily the best or the only way to improve agricultural production, as implied by much current thinking based on idealizations of ‘modern agriculture.’

Farmers should start with whatever crop varieties have the greatest genetic potential for producing desired benefits in their particular environments and circumstances. These may be newly-developed ‘improved’ varieties. But for a given environment and circumstance, it is possible that the most suitable genetic endowment will be found among ‘unimproved’ landraces. This is an empirical question.

Decisions among varieties need to take into account many economic, social, and long-term environmental considerations that arise beyond agronomic criteria of immediate relevance. Newer varieties are not always better varieties, having been selected and bred for certain traits, usually stressing yield over other characteristics. There are almost always some tradeoffs among traits.

The first statement of what constituted SRI, without attempting a full explanation for its effectiveness, was Laulanie’s 1993 article in the Belgian journal Tropicultura,[2] followed by Justin Rabenandrasana’s article in the ILEIA Newsletter in 1999.[3] This was followed by the publication of a paper that I had prepared for a Bellagio conference on agroecological innovations held in April 1999.[4] None of these presentations received much attention, and none created any waves of interest.

The first presentation on SRI that attempted some synthesis of what was known about SRI, and this article did attract attention, and considerable push-back, was published in 2002 in the journal Agricultural Systems.[5] The controversy that it engendered is discussed in Chapter 28 along with the controversy that ensued. The 2002 article’s analysis was backed up by publication almost concurrently in the proceedings of an IRRI/Wageningen workshop, reporting the results of the factorial trials summarized at the beginning of Chapter 7.

These factorial trial results are consistent with the explanations put forward throughout Part I. They were outlined in an ensuing article published in 2003 in the International Journal of Agricultural Sustainability.[6] However, the debate about SRI quickly became framed in terms of the plausibility of reported maximum results rather than an examination of any evidence that would contradict or invalidate those reports (Chapter 10).

In 2003, a first attempt was made at a ‘causal model’ to account for the SRI results that were being seen and measured in farmers’ fields as well as from experimental trials. The diagram below was presented at an international conference held on a campus of the Tamil Nadu Agricultural University.[7] The diagram, not yet a complete model, was published together with other papers from the conference in a new Indian agricultural journal and did not get much attention beyond India.[8]

Anx 1 2.jpg

The next attempt to organize the various factors that comprise SRI was made in Japan in 2005 by Takeshi Horie, a senior rice scientist at Kyoto University, and some of his colleagues.[9] Prof. Horie was at the time a member of the board of directors of WARDA, the African rice research center in West Africa. Subsequently he was appointed director-general of Japan’s National Agricultural Research Organization (NARO), which is comparable to the USDA program and facility operating at Beltsville, MD.

While Horie remained agnostic about the top yields reported for SRI in Madagascar, he and his co-authors pointed out that most of the recommended SRI practices had been used, although not all together, by most of the Japanese rice farmers who won Japan’s national prize for highest rice yield during the 1950s and 1960s. They also pointed out research by Japanese rice scientists that supported the respective practices for SRI. Having such a treatment of SRI by a rice scientist as eminent as Prof. Horie was helpful, although his accounting for SRI’s effectiveness was not given much attention outside of Japan.[10]

The next year, a PhD candidate at the Asian Institute of Technology in Bangkok, Abha Mishra, published an assessment of the scientific foundations for SRI written with her thesis advisors, respectively at AIT, in the FAO, and at the University of Queensland in Australia. This article was based on the literature review that Abha had done in preparation for doing her thesis research on SRI.[11]

From the existing literature, it could be shown how the greater productivity of SRI-grown plants was consistent with much of the accepted scientific knowledge about the effects of reduced plant density, soil nitrogen availability, plant architecture, root oxidation activity, aerobic soil conditions, use of compost, microbial responses, plant growth hormones, delayed senescence, and other factors. The article’s Figure 2 brought these factors together in a model shown below. This model integrated for the first time into a ‘flow diagram’ format the multiple factors that contribute to SRI performance.

Anx 2 4.jpg

Integrated model of the high-yielding rice plant under SRI management practices. All variables are shown as functions (f ) of the variables that drive them (AVN = available nitrogen, AWD = alternative wetting and drying), from Mishra et al. (2006).

This causal model was followed five years later by further integrative analyses done by agricultural scientists in the Netherlands and in Japan in 2011,[12] and several more followed.[13] The diagram below shows connections among various causal factors that can account for SRI’s effectiveness which Amod Thakur and associates highlighted in the analysis that they published in 2016.

Anx 3 5.jpg

None of these presentations, being published as journal articles, could go into as much detail as has been possible in some of this book’s longer treatments of the respective subjects. Part I has undertaken to consolidate and share an understanding that does not require extensive scientific training of what is involved in SRI as it was originally understood, and then as it has become better understood and more diversified through the past 20 years of research and documentation.[14] Going into full detail on SRI would have made this Part I several times longer.

It was timely that while concluding the drafting of Part I, I came across, tacked up on a campus bulletin board a Cornell, an apt reminder by a distinguished professor of economics and dean of the faculty at Harvard University, Henry Rosovsky: Never underestimate the difficulty of changing false beliefs by facts.

It is unfortunate that so many farmers who grow rice and so many scientists who study rice have held onto beliefs that, however plausible they might be, are contradicted by evidence. Gaining acceptance of SRI, which is the focus of Part II chapters, has proceeded more slowly than facts and results would warrant. However, it has succeeded in many ways and in many countries as seen in the chapters that follow in Parts II and III.


[1] This was examined in various respects by more than 100 contributors from 28 countries in the volume in Biological Approaches to Sustainable Soil Systems, discussed in Chapter 5. A 2nd edition of this book is being produced with revised and updated chapters, to be published by CRC Press in 2021.

[2] ‘Le système de riziculture intensive malgach,’ Tropicultura 11: 110-114 (1993), republished in English, ‘Intensive rice farming in Madagascar,’ Tropicultura 29: 183-187 (2011).

[3] ‘Revolution in rice intensification in Madagascar,’ ILEIA Newsletter 15: 48-49 (1999).

[4] ‘Agroecological implications of the System of Rice Intensification,’ Environment, Development and Sustainability 1: 297-313 (1999), subsequently published in the conference proceedings as ‘Opportunities for raising yields by changing management practices: The System of Rice Intensification in Madagascar,’ in Agroecological Innovations: Increasing Food Production with Participatory Development, ed. N. Uphoff, pages 146-161, Earthscan, London (2002).

[5] W.A. Stoop, N. Uphoff and A. Kassam, ‘Research issues raised for the agricultural sciences by the System of Rice Intensification (SRI) from Madagascar: Opportunities for improving farming systems for resource-limited farmers,’ Agricultural Systems 71:249-274 (2002).

[6] N. Uphoff, ‘Higher yields with fewer external inputs? The System of Rice Intensification and potential contributions to agricultural sustainability,’ International Journal of Agricultural Sustainability, 1: 38-50 (2003).

[7] The International Symposium on Transitions in Agriculture for Enhancing Water Productivity held at TNAU’s Agricultural College and Research Institute in Killikulam, India, was organized and hosted by T.M. Thiyagarajan, recently appointed dean of the campus. The symposium was co-sponsored with the International Rice Research Institute (IRRI).

[8] N. Uphoff, ‘Possible explanations for the productivity gains achieved with the System of Rice Intensification (SRI),’ published in the Indian Journal of Agriculture and Resource Management (2004). The diagram has had some dissemination as seen from its recent inclusion in an article from ICAR’s Indian Institute for Soil and Water Conservation:     D. Dinesh, A. Baskar, D. Jinger, V. Kakade and K. Rajan, ‘System of Rice Intensification -- A boon to Indian farmers: A review,’ Annals of Agricultural Research, New Series, 40: 123-139 (2019).

[9] T. Horie, T. Shiraiwa, K. Homma, K. Katsura, S. Maeda, and H. Yoshida, ‘Can yields of lowland rice resume the increases that they showed in the 1980s?’ Plant Production Science, 8: 257-272 (2005).

[10] When I talked with Prof. Horie at the 2nd International Rice Congress in New Delhi in 2006 and expressed my disagreements with the crop modelling exercises that IRRI scientists were citing to ‘disprove’ the possibility of SRI’s top reported yields, he said that he himself put little stock in these models’ conclusions. Why? Because he had himself helped to develop them for IRRI and knew how limited was their utility. Horie kindly invited me to give seminars on SRI to his colleagues and students first at Kyoto University in 2005 and 2008 and also at the National Agricultural Research Organization in 2007.

[11] A. Mishra, M. Whitten, J. W. Ketelaar and V.M. Salokhe, ‘The System of Rice Intensification (SRI): A challenge for science and an opportunity for farmer empowerment toward sustainable agriculture,’ International Journal of Agricultural Sustainability 4: 193-212 (2006). Abha published several articles from her thesis. The first and most important was by Mishra and Salokhe, ‘Seedling characteristics and the early growth of transplanted rice under different water regimes,’ Experimental Agriculture 44: 1-19 (2008). Abha’s research is reported on in Chapter 9. See also her mini-memoire describing how the article came to be written.

[12] W.A. Stoop, ‘The scientific case for system of rice intensification and its relevance for sustainable crop intensification,’ International Journal of Agricultural Sustainability 9: 443-455 (2011); K. Toriyama and H. Ando, ‘Towards an understanding of the high productivity of rice with System of Rice Intensification (SRI) management from the perspective of soil and plant physiological processes,’ Soil Science and Plant Nutrition 57: 636-649 (2011).

[13] A.K. Thakur, N. Uphoff and W. Stoop, ‘Scientific underpinnings of the System of Rice Intensification (SRI): What is known so far?’ Advances in Agronomy 135: 147-179 (2015); N. Uphoff, ‘SRI: An agroecological strategy to meet multiple objectives with reduced reliance on inputs,’ Agroecology and Sustainable Food Systems 41: 825-854 (2017). The latter analysis focused on how and why it is possible to get greater crop output with reductions in inputs.

[14] Researchers at Wageningen University in the Netherlands, as mentioned in Chapter 8, issued a long report on their study of SRI for the Bill and Melinda Gates Foundation in 2011. While the Wageningen study discussed the origins of SRI, it focused mostly on the dissemination of SRI, which is the focus of Part III of these memoires.

     The Wageningen study did not delve into gaining an understanding of the mechanisms and impacts of SRI application, which was the objective of the consortium formed by Wageningen, Cornell and IRRI researchers in 2008 (Chapter 8). The Wageningen researchers in this study viewed SRI in a reductionist way more than is done in Part I, which maps the evolution of the ideas that comprise SRI, when and how they were comprehended and applied.

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