Template:Chapters 2.11
2.11 - Analysis of the System of Rice Intensification (SRI) for Smallholder Farmers
Marcus Lam , University of Guelph,Canada
Suggested citation for this chapter.
Lam,M. (2022)Analysis of the System of Rice Intensification (SRI) for Smallholder Farmers. In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Introducing the System of Rice Intensification (SRI)
Rice is a staple food for over 50% of the world’s population and is especially important in Asia, accounting for 90% of the world’s rice production (Dass et al., 2015). As of 2021/22, global rice production was 520.8 million tonnes (Food Outlook – Biannual Report on Global Food Markets, 2023). It was thought that rice was best grown when submerged underwater or when the soil was very wet (Uphoff, 2006). An example of this type of rice agriculture is in the form of rice paddies. This traditional practice of flooding rice fields uses a significant amount of water while also producing significant amounts of greenhouse gases (IRRI, 2013).
The System of Rice Intensification (SRI) is a collection of scientific methods to help farmers earn more income by reducing the amount of water, seeds, and fertilizers required (IRRI, 2013). Some of the basic steps of the SRI method include planting the rice seedlings while they are younger, planting the seedlings in a square grid pattern with space in between the seedlings, watering, adding fertilizer if needed, and managing the weeds.
One of the main focuses of the SRI method is reducing the amount of irrigation water required. It reduces irrigation water by 25-50% by keeping paddy soil well drained and moist rather than flooded or by alternating between wet and dry cycles during production (Uphoff, 2006). By reducing water requirements for rice production along with other SRI implementations, farmers can increase yields by 50-100% (Uphoff, 2006). The main challenging is managing weeds which has to be done either by hand or mechanically. This issue will be evaluated in a later part of this chapter.
Guide on How-To Implement the SRI Method
As previously mentioned, the SRI Method is a collection of scientific methods. There are 6 main concepts to the SRI method (Dass et al., 2015). The first concept involves transplanting the rice seedlings when they are 8-12 days old (Dass et al., 2015). Concept 2 is planting the seedlings in a square grid pattern with each seedling planted 25 cm x 25 cm apart. Concept 3 involves planting the young seedlings quickly and ensuring the roots are shaped like an L letter shape in the soil. Concept 4 is watering the fields regularly where the soil stays wet/moist but not flooded to ensure aeration and proper drainage, or alternating between wet and dry cycles. Concept 5 is providing the soil nutrients through organic or inorganic fertilizers. Concept 6 is managing the weeds in the field at 10-12, 22-25, and 40-42 days after planting either by hand or mechanically (Dass et al., 2015).
Picture Instructions for SRI Method
Figure 1. 8-12 day old seedlings ready for transplanting into the field: (https://www.youtube.com/watch?v=DiEtrI09sJs).
Figure 2. 8-12 day old seedling with L shape roots ready for planting (https://www.youtube.com/watch?v=DiEtrI09sJs).
Figure 3. Planting the seedlings in a square grid pattern (https://www.youtube.com/watch?v=DiEtrI09sJs).
Figure 4. Using a string to mark how far apart to plant seedlings (https://www.youtube.com/watch?v=FVtmRf_awBU).
Figure 5. A Long-handled weed puller (top left picture) and a Cono-weeder for rice paddies (bottom right picture) There are other tools that can be used or made to help manage weeds. Please see links in “Useful Links to get Started” section below for more information (http://www.sakbooks.com/uploads/8/1/5/7/81574912/7.2__south_asian.pdf).
Benefits of the SRI Method
A primary benefit of using the SRI method involves reducing irrigation water use (International Rice Research Institute., n.d.). Using the SRI, water requirements were reduced by 50% while doubling yield compared to conventional paddy flooding (Surendran et al., 2021). One example of SRI proving efficient is a study in 2021 by Mishra et al. showing that in Cambodia, Laos, Thailand, and Vietnam, average rice yield increased by 52%, labor productivity increased by 64%, water productivity by 61%, and efficiency of mineral fertilizer-use rose by 163% (the data from table 10 in study says 163%)(Surendran et al., 2021). Another study by Thakur in 2018 showed 58% higher yield with 16% less water than conventional farming practices in India (Surendran et al., 2021). Compared to traditional flooding, SRI had a roughly 45% reduction in water-use and major improvements to water-use-efficiency (Dass et al., 2015).
Limitations of the SRI Method
A primary limitation to SRI is the need to remove weeds manually or mechanically due to lack of field flooding as a weed suppressant (IRRI, n.d.). Rice during its early development stages is highly sensitive to water shortages, and so, it is important to maintain soil moisture levels, or else yields may decrease (Surendran et al., 2021). Another limitation/ potential risk to those who use the SRI method is that weeds can cause up to an 80% reduction in yields, which for small scale farmers would be devastating (Surendran et al., 2021). Although weeds pose a threat to production yields and have the potential to increase labor, tools such as the Cono-weeder, rotary hoe, or a power weeder can be used. These also provide a form of aeration to the soil (Surendran et al., 2021).
When SRI was initially introduced, there were concerns that the increase in labor would outweigh the benefits, but these were quickly disproved as farmers became more proficient and utilized mechanization. One main reason that farmers in India and China have implemented SRI was due to its labor savings. An interesting method of saving labor while also suppressing weeds would be intercropping as seen in Northeastern Thailand where yields increased while intercropping mung beans. Another example of this would be from SRI farmers in Vietnam who grew mulched no-till potatoes in rotation with SRI rice, leading to 40-70% less labor (Kassam et al., 2011).
Conclusion
While there are still areas for improvement within the SRI method, it has proven to increase yields while also reducing costs, resulting in increased incomes. Despite the SRI method proving to be efficient, it is useless if smallholder farmers do not understand how to implement it properly or lack the resources to help with implementation.
Practical Resources to Get Started
- These links go to a picture book that gives information about tools and ways to remove weeds.
For South Asia click this link. http://www.sakbooks.com/uploads/8/1/5/7/81574912/7.2__south_asian.pdf
For East/ Southeast Asia click this link. http://www.sakbooks.com/uploads/8/1/5/7/81574912/7.2e.s.a.pdf
There is currently an issue with the SubSaharan Africa / Caribbean page but the pictures in the links above should be the same.
- For videos on effective weed management click the links below here.
https://www.accessagriculture.org/effective-weed-management-rice
This video shows a rotary weeder. https://www.accessagriculture.org/rotary-weeder?cat_id=50
- This video contains a lot of information. It shows how the SRI can be changed to fit the environment you are in. It also shows an easy measuring tool that can be made by attaching a long string between two sticks that create a long line, and having smaller strings tied on the big string at equal spacing to show rice seedling planting distance.
https://www.youtube.com/watch?v=FVtmRf_awBU
- This video shows SRI implemented by farmers in Kilosa, Tanzania: https://www.youtube.com/watch?v=KrBcwdAcYAc
- This an example video of SRI from an ECHO Asia Farm https://www.youtube.com/watch?v=DiEtrI09sJs
- This website from the International Rice Research Institute (IRRI) provides information for all parts of rice production. Home page: http://www.knowledgebank.irri.org/
This page has sections for what to do before planting your rice like choosing what type of rice to plant, how to prepare your field, make sure you have good seeds, etc.: http://www.knowledgebank.irri.org/step-by-step-production/pre-planting
This page has information on when you are growing your rice. It has information on how to plant, manage water, control weeds, etc.: http://www.knowledgebank.irri.org/step-by-step-production/growth
This page is about what to do when you are ready to harvest and what to do after: http://www.knowledgebank.irri.org/step-by-step-production/postharvest
References
1. Dass, A., Kaur, R., Choudhary, A. K., Pooniya, V., Raj, R., & Rana, K. S. (2015). System of rice (Oryza sativa) intensification for higher productivity and resource-use efficiency-A review. In Indian Journal of Agronomy 60 (1). http://www.slideshare.net/SRI.CORNELL/
2. Food Outlook – Biannual report on global food markets. (2023). In Food Outlook – Biannual report on global food markets. https://doi.org/10.4060/cc3020en
3. International Rice Research Institute. (n.d.). Rice Almanac : Source Book for One of the Most Economic Activities on Earth. http://books.irri.org/0851996361_content.pdf
4. Kassam, A., Stoop, W., & Uphoff, N. (2011). Review of SRI modifications in rice crop and water management and research issues for making further improvements in agricultural and water productivity. Paddy and Water Environment, 9(1), 163–180. https://doi.org/10.1007/s10333-011-0259-1
5. Surendran, U., Raja, P., Jayakumar, M., & Subramoniam, S. R. (2021). Use of efficient water saving techniques for production of rice in India under climate change scenario: A critical review. Journal of Cleaner Production, 309, 127272. https://doi.org/10.1016/J.JCLEPRO.2021.127272
6. Uphoff, N. (n.d.). Increasing water savings while raising rice yields with the system of rice intensification (SRI). Cornell University. http://sri.cals.cornell.edu/conferences/2irc1006/2IRCntu.pdf