The abbreviation SRI can stand for a number of things: Socially Responsible Investing[i], Scholastic Reading Inventory[ii], even the Stanford Research Institute[iii]. In climate and agricultural circles, however, SRI stands for System of Rice Intensification[iv]: a revolutionary method of growing rice developed by a French Jesuit in Madagascar in the 1980s. From humble beginnings in the impoverished fields of southern Africa arose what Cornell professor Norman Uphoff calls[v] “one of the most remarkable agricultural innovations of the last century.”
Miraculous in its potential to exponentially increase rice production while decreasing water use, methane emissions, and cost to farmers, le système de riziculture intensive (in the original French of its creator) has slowly but steadily taken root in the areas that need it most: Southeast Asia and Africa, two regions characterized by poverty and climate change.
The numbers vary by location, but all are impressive. According to Cornell University’s SRI International Network and Resources Center[vi] (SRI-Rice), yields can increase by at least 20-100% using up to 90% fewer seeds and 50% less water. Equally important, SRI rice produces fewer methane (CH4) omissions, uses less chemical fertilizers, favors small farmers over conventional corporate agriculture, and empowers women and girls.
In other words, SRI fundamentally lowers the carbon footprint of the world’s most important food staple while increasing its ability to feed our growing population. It is not the only way sustainable method of growing rice, but it is, in Project Drawdown’s words, “the most promising.”[vii] That’s why the organization[viii] lists SRI as #53[ix] on its top 100 solutions to reverse climate change.
SRI Up Close: How It Works
The notion that one of the most significant agricultural innovations of the 20th century arose not in a multibillion-dollar lab but in the dry and unforgiving fields of Madagascar gets to the heart of SRI: it is counterintuitive in many ways[x], using fewer, smaller, and younger seeds to get more, bigger, and more resilient harvests. Sent by the Jesuits from his native France to assist the poor farmers in the 1960s, Father Henri de Laulanié developed SRI[xi] first by observing the unconventional adaptations of a handful of farmers who produced bigger yields and then by drawing upon his own degree in agriculture to offer other innovations.
SRI fundamentally introduces innovations at three key stages or steps of rice production[xii]:
- When planting, farmers place seedlings in a grid pattern with plenty of room between each plant so that it receives enough water, sunlight, and nutrients. In traditional rice cultivation, seedlings are bunched close together and thus compete for these resources.
- SRI does not flood fields in order to grow rice, since overwatering kills root systems[xiii], thus lowering the quality of the soil, and also leads to the methanogenesis[xiv] that makes rice production such a potent greenhouse gas producer. Alternate wetting and drying (a method covered in #24, Improved Rice Cultivation[xv]) and other intermittent watering methods are used not only to save money and water but also to keep roots and soil healthy and full of nutrients.
- Since farmers flood rice fields in part to suffocate weeds, tending looks different under SRI, using a simple rotating hoe (houe rotative) to aerate and weed the soil. When Madagascar’s government withdrew subsidies for chemical fertilizers in the 1980s, moreover, Laulanié and the farmers found that yields grew even larger[xvi] when they switched to compost and biomass.
As Erika Styger and Norman Uphoff of Cornell’s SRI-Rice[xvii] observe[xviii], yields improve most—as does the carbon footprint—if all three principles of SRI are adapted. However, even partial implementation can provide notable benefits, and the next section will reveal.
Styger and Uphoff also note that it takes about three rice growing seasons for farmers to feel truly confident in SRI principles, moving from watching demonstrations in the first season to doing it themselves in the second and integrating these practices into communal efforts like shared irrigation and labor in the third.
Examples of Successful SRI
On the SRI-Rice website, you can find a bibliography listing more than one thousand journal articles[xix] examining SRI success stories all around the globe. Estimates[xx] are that as many as 20 million farmers have implemented SRI practices in more than 60 countries worldwide.
Perhaps the most famous example is Sumant Kumar, the Indian farmer who purportedly[xxi] set a world record for rice yields in 2012[xxii] with an astonishing 22.4 tons of rice per hectare. (While the record itself has come under scrutiny, he produced far more than the average 4-5 tons[xxiii] per hectare.)
While records represent the extreme exceptions, many case studies record truly impressive benefits. A 3-year study of SRI methods[xxiv] used by 50,00 farmers in 13 west African countries, for example, found that yields increased 56% in irrigated areas and 86% in rainfed areas—a finding that underscores the fact that SRI works best when conventional agricultural practices are used as little as possible. At the same time, these farmers saw their income rise by 41%[xxv].
Similarly, farmers in northern Vietnam—far from the fertile Mekong Delta and thus far poorer and more vulnerable—who used SRI made $17.6 million USD (VNC 370 billion) more[xxvi] than their conventional counterparts in 2011.
While increased income will appeal first and foremost to most farmers, sustainability is crucial to long-term survival. Studies have shown that the total global warming potential (GWP) drops by at least 20-30%[xxvii] when SRI methods replace traditional rice cultivation. Moreover, SRI rice is more resilient. A Japanese study[xxviii], for instance, found that only 10% of a field planted using SRI methods suffered storm damage—compared to 55% of the crop in an adjacent field using conventional ones. Most importantly, SRI can reduce methane emissions by anywhere from 35-70%[xxix]. Drawdown estimates that 3.1 gigatons of GHGs[xxx] can be sequestered or removed if SRI expands to 133 million acres by 2050.
SRI is so exciting and important because our must vulnerable populations depend on rice. As Oxfam notes[xxxi], “rice is the single-largest source of employment and income for rural people” worldwide, with 11% of all arable land on Earth devoted to it. SRI is a shining example of the best climate change strategies: simple and cheap to implement, it improves lives while it reduces emissions. As Uphoff beautifully puts it[xxxii], SRI is based on the notion that “smaller would become bigger, and less could produce more. This sounds like nonsense; but it is possible and true.”
[vii] Drawdown, 48.
[xii] Drawdown, 48.
[xiv] Drawdown, 48.
[xv] LINK TO POST WHEN AVAILABLE.
[xviii] https://cgspace.cgiar.org/bitstream/handle/10568/77040/GACSA Practice Brief- SRI FINAL.pdf?sequence=1&isAllowed=y.
[xxii] Drawdown, 48.
[xxvii] https://cgspace.cgiar.org/bitstream/handle/10568/77040/GACSA Practice Brief- SRI FINAL.pdf?sequence=1&isAllowed=y.
[xxix] Drawdown, 49.