System of Rice Intensification (SRI)

  • About

  • Origins and definition of SRI

  • Evaluating SRI

  • Helping SRI farmers

  • Related items

 sri-origins

The System of Rice Intensification (SRI) is an evolving set of practices, principles, and philosophies aimed at increasing the productivity of irrigated rice by changing the management of plants, soil, water and nutrients.

According to the SRI International Network and Resources Center at Cornell University, SRI “is not a recipe of precise things to do.” The flexibility in SRI’s definition of practices renders SRI a challenge for evaluation and assessment of adoption.

Offering farmers a menu of practices that are science-based, have a solid track record of performance, and that can be tested, adapted, and integrated by farmers locally, is a powerful mechanism to bring improvements to their production systems. Such a menu of practices tallies well with IRRI’s approach of offering best management practices as listed in the Rice Knowledge Bank.

SRI practitioners can try out best management practices locally and incorporate them into their practices where they find them successful to compliment and build on their current practices.

 sri-about

The System of Rice Intensification (SRI) was originally developed in the highlands of Madagascar by the French Jesuit missionary father Henri de Laulanié, who published his results in the journal Tropicultura in 1993 (with an English translation published in 2011). He brought together three essential principles: planting young seedlings, planting single seedlings, and applying minimal irrigation water to keep the soil just at or below saturation. These three essential elements were complemented by “general principles of improved rice cultivation” encompassing recommendations for drainage and irrigation in general, nursery establishment, careful and wide transplanting, land preparation, weeding, and harvest.

Since its development by de Laulanié, SRI spread outside of Madagascar, and its principles evolved into a suite of flexible principles to be adapted to local conditions rather than a fixed technological package. SRI is now being practiced in a number of rice-growing countries.

Defining SRI

According to the SRI International Network and Resources Center at Cornell University, SRI is currently “based upon a set of principles and practices for increasing the productivity of irrigated rice by changing the management of plants, soil, water, and nutrients” and it “is not a recipe of precise things to do.” In summary, they indicate that the major SRI principles follow:

  • Rice plants: Transplanted very young seedlings carefully and quickly, and singly, and space them widely in a square grid pattern
  • Soil: Keep moist but well drained with good structure and organic matter.
  • Water: Apply a minimum of water to keep soil moist but well drained.
  • Nutrients: Augment soil nutrients preferably with compost.
  • Weeds: Do early and regular weeding, using hand or mechanical weed control and incorporating weeds into the soil.

IRRI's Leaf Color Chart is promoted among  SRI practitioners in Tamil Nadu, IndiaHowever, none of the above is cast in stone and even transplanting older seedlings, or transplanting more than one seedling, can be considered as SRI if site-specific conditions call for it. For example, in Cambodia, SRI farmers transplant 25-day old seedlings, sometimes in more than one seedling per hill, and not always in square patterns. Although the use of compost or manure is preferred, the use of chemical fertilizers is not excluded and is even encouraged by some SRI practitioners such as those in the Indian state of Tamil Nadu who promote the use of IRRI’s Leaf Color Chart to guide fertilizer application. Norman Uphoff, a well-known advocate of SRI, states that SRI should offer a long menu of practices for farmers to choose from.

SRI encourages engagement with farmers and local testing and adaptation of practices and technologies. SRI is therefore continually changing and SRI as adopted by individual farmers may or may not include the adoption of the above practices as specified, and may include the adoption some other "best mangement practices." For example, some SRI practitioners are experimenting with direct seeding.

sri-evaluating

The System of Rice Intensification (SRI) is a dynamic set of principles and practices aimed at increasing the productivity of irrigated rice. The flexibility in SRI’s definition of practices renders SRI a challenge for evaluation and assessment of adoption.

Proponents of SRI highlight experimental results of superior SRI performance with practices that only partially follow the original or with modified practices (justified because practices should be locally adapted), while they reject experimental results of inferior SRI performance based on the fact that practices were incompletely or wrongly implemented. Critics of SRI use the same arguments the other way around.

For example, Dr. A.J. McDonald and his colleagues at Cornell University published a paper in Field Crops Research in 2005 that evaluated the productivity of SRI with respect to best management practices by analyzing 40 site-years of SRI versus best management practices comparisons published in scientific journals. In addition to Madagascar, data sets came from studies in Nepal, China, Thailand, Lao PDR, India, Sri Lanka, Indonesia, Bangladesh and the Philippines. His study concludes that

“Aside from one set of experiments in Madagascar where SRI more than doubled rice productivity with respect to BMP, we found no evidence of a systematic or even occasional yield advantage of this magnitude elsewhere. Indeed none of the 35 other experimental records demonstrated yield increases that exceeded BMP by more than 22%. Excluding the Madagascar examples, the typical SRI outcome was negative, with 24 of 35 site-years demonstrating inferior yields…”

The publication of this paper prompted a response by Dr. Norman Uphoff and a response to that again by Dr. McDonald. The debate continues with many others reporting various findings.

The situation is even more challenging in adoption studies where farmers’ practices are often labeled as SRI that have only partial adoption of the promoted practices or that adopted other best management practices under the banner of SRI.

sri-helpOffering farmers a menu of practices that are science-based, have a solid track record of performance, and that can be tested, adapted, and integrated by farmers locally, is a powerful mechanism to bring improvements to their production systems. Such a menu of practices tallies well with IRRI’s approach of offering best management practices as listed in the Rice Knowledge Bank.

Most of the complementary techniques or “general principles of improved rice cultivation” suggested by the originator of the System of Rice Intensification (SRI), Henri de Laulanié, are well documented best management practices, such as square planting, good land leveling, good water control by separate irrigation and drainage channels to individual fields, mechanical weeding using rotary or cono weeders, rouging of grassy weeds, and draining of fields prior to harvest to facilitate maturation.

As institutions, such as IRRI, build on these practical and proven best management practices, SRI practitioners can try them out locally and incorporate them into their practices where they find them successful. IRRI has long recognized the importance of farmer participation in research to aid the development of suitable technologies and hasten their uptake.

SRI as a movement is a strong force to bring together farmers, extension and development agents, scientists, and other stakeholders in a participatory manner to adopt and integrate technologies such as best management practices that can increase yield, resource-use efficiencies, and income.

IRRI and SRI

IRRI is not currently conducting any research to compare SRI to current best management practices given the inherent challenges of evaluating SRI.

We are focusing our research investment in developing new and improved best management practices scientifically proven to help rice farmers increase their rice yields in an environmentally sustainable way. We work with farmers in developing these practices and technologies and share them with rice farmers around the world, including with farmers who practice SRI. In doing so, we target our resources in the most effective way to assist rice farmers. SRI can be used as a mechanism to help locally test and adapt new best management practices and we look forward to working with SRI practitioners in trying these technologies out.