What is 'SRI' and how can it help feed the world?
The System of Rice Intensification, or SRI, is a method of rice farming with the potential to increase prductivity and reduce the effects of climate change. Similar methods have been used with other crops, to great success.
The System of Rice Intensification, known as SRI, can reduce water requirements, increase land productivity, and promote less reliance on artificial fertilizers, pesticides, herbicides, and other agrochemicals, all while buffering against the effects of climate change and reducing greenhouse gases (GHG).
In a recent interview with Food Tank, Professor Norman Uphoff at Cornell, who has been studying the impacts of SRI management for more than 15 years, describes SRI as not a fixed technology, but, instead, as a set of principles and ideas. Ideas that translate into a combination of agroeconomic practices, which might differ depending on agro-ecological and cropping system conditions, but that can have widespread benefits.
Application of SRI practices can raise household incomes, enhance soil fertility, and protect crops against climatic, pest, and disease stresses.
For irrigated rice production, for which SRI was first developed, farmers transplant young, single seedlings, spacing them widely in a grid pattern, keeping soils moist and fertile, but not flooded, enhancing them with compost and other sources of organic nutrients, doing regular and early weeding that aerates the soil, and incorporating weeds into the soil to decompose.
According to Dr. Erika Styger, Director of Programs of SRI-Rice, the SRI International Network and Resources Center at Cornell University, SRI is already invaluable to farmers in Cambodia, China, Cuba, India, Indonesia, Kenya, Mali, Myanmar, the Philippines, and Vietnam by fostering larger, healthier, better-performing root systems and canopies above-ground. Benefits from applying the SRI methodology and modifying practices accordingly have occurred already in more than 50 countries.
The broader application of SRI ideas and methods is referred to as the System of Crop Intensification (SCI). SCI practices have already been developed for wheat, finger millet, tef, sugarcane, mustard, and sorghum. A World Bank publication reports that at least 100,000 farmers in Bihar state of India are using SRI methods for rice and also with other crops. Increases in rice yields, according to the report, were 82 percent, and incomes were raised by 250 percent. The methods adapted for wheat, pulses, oilseeds and vegetables resulted in yield increases by 72 percent, 56 percent, 50 percent, and 20 percent, respectively, while the respective increases in income were 86 percent, 67 percent, 93 percent, and 47 percent.
In Ethiopia, SCI practices have been developed for tef as well as other crops. Results from the System of Tef Intensification (STI) have been so successful that the government’s Agricultural Transformation Agency (ATA) is supporting its extension.
In India, the System of Sugarcane Intensification (SSI) has been very successful, and SSI is also being introduced in Cuba. According to the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT) and the Worldwide Fund for Nature (WWF), SSI practices can generate 20-100 percent greater sugarcane yield with 30 percent lower water requirements and a 25 percent reduction in chemical inputs. ICRISAT and WWF have produced a manual on the adaptations of the SRI principles to sugarcane production.
Today, Food Tank would like to highlight five ways how applying SRI practices and ideas can help "feed the world," support family farmers, and help protect the environment.
1. Reduce water use — In the 50 plus countries in which the benefits of SRI have already been demonstrated, there has been a 30-50 percent decrease in water use compared to growing the same varieties on the same soil under flooded conditions. According to Oxfam America, “the significance of SRI lies not only in enabling farmers to increase yields with less water, but in the basket of associated social and environmental benefits.”
2. Reduce costs associated with farming — By reducing their reliance on purchased inputs, farmers can cut their costs of production, an important consideration for cash-poor households. An average reduction of 23 percent was calculated from on-farm evaluations of impacts from SRI methods in Bangladesh, Cambodia, China, India, Indonesia, Nepal, Sri Lanka, and Vietnam.
3. Increasing household income — According to Uphoff, “No other innovation offers the net economic returns that SRI can provide” because costs can be reduced while income goes up. This is especially true in regions of the world where rice production is a break-even endeavor. In northern Myanmar, for example, under rainfed conditions, households' net incomes from rice production using SRI methods were increased eight-fold in real terms.
4. Creating resilience against climate change — According to areport published in theProceedings of the National Academy of Sciences of the United States of America (PNAS), there is direct evidence of decreased rice yields due to higher night temperatures as a result of global warming. Practices will need to change to deal with these changing conditions. According to Uphoff, SRI’s buffering against climate change is attributable to two things: 1) improvements in crop root systems, with larger, better roots and less degeneration than under flooded, hypoxic conditions; and 2) soil biodiversity and biological activity. Uphoff points to the beneficial effects that soil microorganisms can have when residing within rice plants as symbiotic endophytes. They can have an effect on plants' chlorophyll levels and photosynthesis and even on their expression of genetic potential.
5. Increase yields — Uphoff first accepted the potential of SRI in 1997 after he visited farmers in Madagascar who had been producing just two tonnes of rice per hectare on their poor soils — by using SRI, they were able to average eight tonnes per hectare for three consecutive seasons on the same soils and with the same varieties, without having to purchase inputs. The average yield increases from on-farm evaluations across eight countries were 47 percent, according to Oxfam America.
After learning about how successful the spread of SRI has been, many assume that SRI research and extension must be well-funded, but the work has been mostly done by dedicated people who are looking and working for innovations that can succeed on farmers' fields, often on a volunteer basis.
Support for basic tasks of advancing knowledge, doing evaluations, and disseminating further innovations for SRI and SCI has been, and still is, minimal. “Although the global network is strong, with a wide variety of well-performing technical innovations spreading in farmers’ fields, scaling-up of SRI is not happening at a pace that smallholder farmers in Africa, Asia, and Latin America are ready for,” says Styger.
Uphoff adds, “We should not need to have food shortages in the world if we would make better use of our existing land, water, seed, labor, and capital resources.”
To learn more about SRI, you can visit Cornell’s SRI-Rice website.