WHAT?

The System of Rice Intensification (SRI)
is a climate-smart agricultural methodology.

SRI is a sustainable agricultural practice that provides ecological, social, and economic benefits to farmers, families, consumers, and businesses.

SRI follows four key principles that produce significantly greater crop yields, simultaneously minimising inputs and greenhouse gas emissions, particularly methane.

SRI is a holistic approach to sustainable rice cultivation

Project Drawdown

WHAT?

The System of Rice Intensification (SRI) promotes collaborative synergies throughout sectors.

The SRI network of government agencies, NGOs, civil society, and the private sector continues to grow in over 60 countries, with a shared goal of more efficient, equitable, and sustained development.

Effective partnerships and collaboration lie at the heart of SRI success.

"to innovate, contribute, and support the human
existence with whatever capacities we respectively have"

Dr. Abha Mishra, Agronomist

HOW?

The System of Rice Intensification (SRI) promotes collaborative synergies throughout sectors.

The SRI network of government agencies, NGOs, civil society, and the private sector continues to grow in over 60 countries, with a shared goal of more efficient, equitable, and sustained development.

Effective partnerships and collaboration lie at the heart of SRI success.

"to innovate, contribute, and support the human
existence with whatever capacities we respectively have"

Dr. Abha Mishra, Agronomist

HOW MUCH?

The System of Rice Intensification (SRI) promotes collaborative synergies throughout sectors.

The SRI network of government agencies, NGOs, civil society, and the private sector continues to grow in over 60 countries, with a shared goal of more efficient, equitable, and sustained development.

Effective partnerships and collaboration lie at the heart of SRI success.

"to innovate, contribute, and support the human
existence with whatever capacities we respectively have"

Dr. Abha Mishra, Agronomist

WHY?

The System of Rice Intensification (SRI) promotes collaborative synergies throughout sectors.

The SRI network of government agencies, NGOs, civil society, and the private sector continues to grow in over 60 countries, with a shared goal of more efficient, equitable, and sustained development.

Effective partnerships and collaboration lie at the heart of SRI success.

"to innovate, contribute, and support the human
existence with whatever capacities we respectively have"

Dr. Abha Mishra, Agronomist

WHO?

The System of Rice Intensification (SRI) promotes collaborative synergies throughout sectors.

The SRI network of government agencies, NGOs, civil society, and the private sector continues to grow in over 60 countries, with a shared goal of more efficient, equitable, and sustained development.

Effective partnerships and collaboration lie at the heart of SRI success.

"to innovate, contribute, and support the human
existence with whatever capacities we respectively have"

Dr. Abha Mishra, Agronomist

WHERE?

The System of Rice Intensification (SRI) promotes collaborative synergies throughout sectors.

The SRI network of government agencies, NGOs, civil society, and the private sector continues to grow in over 60 countries, with a shared goal of more efficient, equitable, and sustained development.

Effective partnerships and collaboration lie at the heart of SRI success.

"to innovate, contribute, and support the human
existence with whatever capacities we respectively have"

Dr. Abha Mishra, Agronomist

What is SRI?

The System of Rice Intensification (SRI) is a climate-smart agricultural methodology for cultivating rice based on four key principles that address plant, soil, and water management.

What are the main principles of SRI?

There are four key principles of SRI which guide how SRI is practiced. These are: the early establishment of healthy plants; low plant density; soil enrichment; and the sparing application of water.

What are the main practices of SRI?

The practices of SRI vary according to the needs, abilities, resources, and local conditions of each farmer. Each of the principles of SRI should be adapted to each farmer's context.

What is AWD?

Alternate Wetting and Drying (AWD), also known as “intermittent irrigation”  is the process of providing water intermittently to rice paddies. AWD can dramatically reduce methane emissions.

What equipment is needed?

SRI does not require additional equipment. A handheld mechanical weeder is a cost-effective investment that can help alleviate labour requirements.

What types of rice can be used with SRI?

The methods of SRI can be applied to all varieties of rice and has been validated with both improved and indigenous varieties.

What investments are needed in SRI?

Although SRI can be implemented without the need to invest in costly resources, there are many areas, such as irrigation development or equipment availability, that could benefit from outside investment in supporting SRI uptake.

What further opportunities does SRI have?

SRI can be used in tandem with other agroecological approaches. The principles of SRI have been applied to other crops, such as wheat, finger-millet, and sugar cane. SRI's beneficial outcomes can help countries to achieve sustainable development goals, such as those called for by the UN.

What is SRI?

The System of Rice Intensification (SRI) is a climate-smart agricultural methodology for cultivating rice. SRI achieves greater yields from reduced inputs, while simultaneously minimising greenhouse gas emissions, particularly methane.

SRI is based on a set of Four Key Principles. These principles are adapted to the needs, skills, priorities, and environment of the rice farmer. Through a variety of different management approaches, such as reducing the density of rice plants, or using alternate wetting and drying (AWD), farmers produce higher yields that are more resilient to the changing climate.


CO_Shuichi Sato

What are the
main principles of SRI?

Since its synthesis in the 1908s, SRI has been guided by four principles. These are to start with young healthy plants; to optimise spacing to minimise competition between plants; to build up fertile and healthy soil; and to apply only the minimum amount of water needed by the rice plants and soil organisms.  

We now need to promote a more nature-based implementation of SRI, given the current over-reliance on agrochemicals and unsustainable degradation of agricultural soils. Therefore, the fifth principle given here is provided with the aim to reduce rice cultivation’s impact on the environment , support sustainable food-systems, and align with the principles of Conservation Agriculture, as practised in India’s Zero Budget Natural Farming movement.

With this adjustment, SRI adds to its existing agro-ecological approach and the beneficial attributes of regenerative, organic, and conservation agriculture.

1. Start with young, healthy plants

2. Optimise spacing to minimise competition between plants

3. Build up healthy and fertile soil

4. Apply only the minimum amount of water needed

5. Think agroeco-logically and practice farming accordingly

What are the main practices of SRI?

The practice of SRI varies according to the needs, abilities, resources, and local conditions of each farmer. Some of the practices can initially seem counter-intuitive as they depart from commonly used practices which have been in use for centuries in rice cultivation.

It is therefore important to understand the reasons behind these practices. Understanding the 'why' behind the 'what' allows the practices to be adopted with confidence and adapted to best suit local conditions.

Rice Management Practice Conventional Practice SRI Practice Why SRI works SRI Principle
Seedling preparation and transplanting
  • There is no seed selection or treatment.
  • Seedlings are much older, anywhere between 25-60 days.
  • Normally planted 3-5 per hill together plunged into soil at variable depths.
  • Start with careful seed selection before sowing the nursery (or if planting seeds directly), so that only well-developed seeds are sown.
  • Raise rice seedlings in an unflooded nursery with enriched soil and with sparse sowing of the seeds. Seed rate is reduced by 80-90% per ha.
  • Transplant young seedlings at the 2-3 leaf stage, usually 8-12 days old, usually before 15 days old, i.e., before the start of their 4th phyllochron of growth.
  • Plant the seedlings quickly after they are removed from the nursery and carefully so as to minimise trauma.
  • Plant the seedlings gently and shallow (just 1-2 cm), avoiding 'J-shape' of the root in soil. Prefer to have 'L-shape' or 'I-shape,' with the tip of the root not pointing upward.
  • The discarded seeds have limited growth potential. It is best to start with only robust seeds.
  • Sparse seeding and no flooding of the nursery encourages better growth of the seedling roots.
  • Careful transplanting minimises 'transplant shock' so that seedlings can resume their growth immediately. Transplanting quickly keeps the roots from drying out.
  • Transplanting before the 4th phyllochron conserves more of the rice plant's innate potential to grow more and larger tillers and roots.
START WITH YOUNG, HEALTHY PLANTS
Spacing
  • High density, around 10-15cm spacing.
  • Reduce plant density (plants per m2) by planting the rice seedlings singly, only one per hill rather than 3 to 6 or more per mill. If the soil is 'poor,' planting two seedlings per hill is okay for the first season or two.
  • Plant seedlings in a square pattern, usually with spacing of 25x25 cm. The plants can be closer if the soil is 'poor,' or wider apart if the soil is very fertile, to achieve optimum density.
  • Over time as SRI practices build up soil fertility, having one plant per hill and spacing wider than 25x25 cm will make demonstrably better use of the land area.
  • Rice plants when not crowded (and flooded) can each express their genetic potential more fully.
  • Such plants will produce more tillers and larger panicles, supported by larger root systems.
  • Spacing should be optimised rather than maximised or minimised. Healthy plants quickly grow to cover the whole area.
  • Sunlight and soil nutrients are more fully harvested and utilised.
OPTIMISE SPACING TO MINIMISE COMPETITION BETWEEN PLANTS
Managing soil fertility and weed control
  • Use of chemical fertilisers
  • Use of chemical pesticides
  • Provide the soil with as much organic matter as possible (compost, mulch, green manure, crop residues, biochar, etc.).
  • Weed control is best done with a mechanical weeder, manual or motorised, criss-crossing the field in perpendicular directions. This is made possible by planting the hills in a square pattern. This kind of weeding stirs up and aerates the surface layer of topsoil while it eliminates weeds.
  • Weeding should begin about 10 days after transplanting (or after the emergence of direct-seeded plants), and it should be repeated every 10-12 days until the canopy closes. This kind of weeding provides soil aeration as well as weed control.
  • Rice plants when not crowded (and flooded) can each express their genetic potential more fully.
  • Such plants will produce more tillers and larger panicles, supported by larger root systems.
  • Spacing should be optimised rather than maximised or minimised. Healthy plants quickly grow to cover the whole area.
  • Sunlight and soil nutrients are more fully harvested and utilised.
BUILD UP HEALTHY AND FERTILE SOIL
Water management and weed control
  • Continuous flooding of rice paddies.
  • Weeding tools or manual weeding.
  • Avoid continuous flooding of rice paddies. Instead, practice alternate wetting-and-drying (AWD).
  • Adjust the timing of the wetting and drying intervals according to soil type and climatic conditions (like rainfall) to provide a minimum but sufficient supply of water for the plants and for sustaining life in the soil.
  • While rice plants can survive in standing water, they are not aquatic plants and do not perform best under flooded conditions.
  • Continuous flooding suffocates the plant roots and also beneficial soil organisms that bolster plant health and growth.
  • The roots of rice plants that are flooded and given N fertiliser do not grow deeply into the soil because water and N are sufficient at the soil surface.
  • A less humid environment makes the above-ground microclimate less hospitable for most insect pests and disease vectors.
  • AWD reduces water consumption in our increasingly water-short world.
  • Aerobic soil rich in organic matter supports the proliferation of beneficial biodiversity in and around the fields.
APPLY ONLY THE MINIMUM AMOUNT OF WATER NEEDED BY THE RICE PLANTS AND BY SOIL ORGANISMS
Environmental and sustainable considerations
  • Not considered
  • To the extent possible, integrate agroecological principles and practices into the farming system, e.g., Conservation Agriculture (CA), Integrated Pest Management (IPM), agroforestry, water harvesting, etc. As feasible, modify one’s farming system to practice SRI Plus
  • Minimise reliance on agrochemical inputs, and as much as possible, end the current chemical-dependence in cultivation practices.
  • Rotate SRI rice-growing with other crops to enhance above- and below-ground biodiversity.
  • Keep the soil covered as much as possible with crop residues, cover crops, intercrops, green manures, etc.
  • Move toward no-tillage of the soil, e.g., with raised beds, to have minimum disturbance of soil systems.
  • SRI methods strengthen rice plants’ innate defence mechanisms against pests and disease, so there is less or no need for agrochemical crop protection.
  • The incidence of pests and diseases is usually reduced below the threshold at which the continued use of agrochemicals becomes uneconomic.
  • Not disturbing the soil through tillage reduces the losses of C and N from the soil system into the atmosphere.The spread of SRI practices, also to other crops, should make possible the reduction, and perhaps an end, of chemical-dependent food production, which will improve plant, soil and human health.
THINK AGROECO-LOGICALLY AND PRACTICE FARMING ACCORDINGLY

SRI +

A variety of  agroecological principles and practices can be integrated with SRI. Conservation Agriculture (CA), Integrated Pest Management (IPM),  water harvesting, aquaculture and horticulture, organic, or biochar rice straw management are some examples. Assessing each location and farmer's context is important to creating a holistic cultivation system that is long-lasting and sustainable.

What is AWD?

Alternate Wetting and Drying (AWD), also known as “intermittent irrigation”, is the process of providing water intermittently to rice paddies.

In contrast, conventional rice farming continuously floods rice paddies. This constant flooding allows methanogens (methane producing organisms) to flourish, resulting in rice farming contributing to over a fifth of man-made methane emissions.

AWD can play a crucial role in global methane reduction. Intermittently applying water to rice paddies keeps the soil in a mostly aerobic condition, passively aerating the soil. Aerobic conditions are not tolerable by methanogens, therefore methane emissions are significantly reduced.

AWD is necessary to avoid the plant roots degenerating. Healthier root systems produce healthier plants, and in turn significantly enhance overall yields.

Additionally, AWD requires a much smaller volume of water. By practising AWD, water input can be reduced by 25-50%; a critical factor as water scarcity and climate shocks increase.


CO_Biksham Gujja, AgSri

What equipment
is needed?

SRI can be practiced without making any additional equipment purchases. A handheld mechanical weeder, however, is a beneficial addition that can significantly reduce the labour efforts involved. Investments in simple mechanisation can usually be returned within the first season for the farmer.

Other equipment used can include: transplanters, markers, direct seeders, land markers, amongst others. Farmers are continually innovating and adapting machinery and equipment to suit their needs. Investing in equipment, logistics, and the infrastructure necessary for both small-holders and large-scale farmers would be a major asset to increasing SRI adoption.


CO_Biksham Gujja, AgSri

What types of rice can be used with SRI?

The methods of SRI can be applied to all varieties of rice.

SRI enables rice plants to more fully express their genetic potential and has shown increased productivity in both improved and indigenous varieties.

Growing indigenous varieties using SRI practices has shown increased yields of 5-10 tons per hectare, while simultaneously lowering production costs.

Indigenous varieties are often preferred by consumers and hold greater market value, so are usually more profitable than newer varieties. SRI can be an attractive option for farmers to help preserve the genetic biodiversity of rice.


CO_Sabarmatee

What are the costs?

A major advantage of SRI is that it can be implemented without purchasing any new resources or equipment.

Unlike many new agricultural technologies, SRI is readily accessible to poor and resource-limited households. SRI capitalises upon strengthening and enhancing the existing biological processes and potentials in rice plants and soil systems. SRI therefore does not require additional inputs; instead the focus is on changing land and crop management practices.

As SRI has no major upfront costs, yet significantly increases yields and profits, SRI can have a direct, positive impact on reducing hunger and poverty, as well as climate change mitigation.

Access to a soil-aerating mechanical weeder is a cost-effective addition which can significantly reduce the labour required. It is not, however, a requirement in practising SRI. This investment can be shared by a number of farmers in a community, thereby dividing the costs.


CO_Gamini Batuwitage

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What are the barriers to SRI?

Many barriers that affect SRI are also barriers impacting conventional rice cultivation. Two main barriers that may restrain SRI adoption are the access and control of water, and labour supply.

Barriers

Water Control

To perform alternate wetting and drying (AWD),
the water supply must be controllable.

Water Access

Participatory Irrigation Management

Investing in participatory irrigation management systems by local and national governments would increase water use efficiency and allow farmers to have greater control over irrigation of crops.

Small Scale Irrigation

Provision of small-scale irrigation, such as solar pumps, allows farmers to have more control over irrigation in regions where rainfall is unreliable and insufficient. 

Biomass Availability

Organic nutrients are important in providing minerals to support soil health and biodiversity of microorganisms in the soil. Using organic matter as green fertiliser instead of synthetic fertiliser results in healthier soils each year that supports greater yields.

Labour Supply

Learning the SRI methodology can initially increase labour demands while new methods are learnt.
SRI may also exacerbate a labour bottleneck during the transplanting phase when a larger number of workers are required in a shorter period of time.

Availability of Mechanical Tools

The availability of equipment such as mechanical weeders, transplanters, and seeders requires improvement.

Pest and Disease Control

The pests and disease that affect conventionally
flooded paddies also affect SRI paddies.



Farmer Attitudes and Psychology

A minimum knowledge and practicality of skills is required to enact SRI methods correctly.

SRI Solutions and benefits

Construct Drainage Systems in Arid Areas

Constructing small drainage channels along the sides and across paddy fields to create raised beds between drainage channels can be an alternative to AWD where water cannot be controlled as easily.

Land Grading and Draining

Proper land grading and provision of draining can allow control in flood-prone areas.

Lower Water Requirements

SRI uses a much lower volume of water to grow greater yields than conventional management practices. Therefore, farmers with less access to water will benefit from SRI practises.  

Shorter Crop Cycles

The shorter crop cycle characterised by SRI allows farmers to grow additional crops such as nitrogen-fixing legumes where some or all of the yield can be composted and used to enrich the soil as green fertiliser. As SRI crops are more land efficient, farmers can also assign areas of their fields to grow crops for use as organic manure. 

Mechanical Tools

Using mechanical tools such as rake or roller-markers can help to alleviate labour time and requirements. 

Collective Investment in Tools

Farmers can collectively invest in equipment to share as a community, greatly reducing the cost of investment. The use of this equipment in SRI practice can have a significant impact on SRI success; this investment is recommended as
a high priority.  

Integrated Pest Management (IPM)

IPM combines multiple strategies to control pests and diseases by working with nature to enhance its potential in the agricultural landscape in a context-specific manner. IPM can be used in tandem with SRI to find locally specific solutions to control diseases and pests in rice fields.

SRI Champions

Physical demonstrations by lead farmers or ‘SRI champions’ using farmer-to-farmer networks can persuade farmers who are unconvinced by SRI. Often, farmers are sceptical in the initial month as the seedlings are barely visible in the soil. However, reassurance from lead farmers, and the use of support materials are a simple and accessible way to educate farmers.

What investments
are needed in SRI?

Investments to enhance a community’s capabilities
are required for SRI practice to reach its full potential.
The following are areas that would benefit greatly from investments.


CO_Gamini Batuwitage

Irrigation Systems

Investing in irrigation management systems is an option to improve water use efficiency and a farmer's control of water. This is particularly important in areas with erratic rainfall. Irrigation systems that require farmers to pay for the fuel or volume of water used can work as an incentive to use SRI due to AWD methods being cheaper than conventional flooding practices.

This style of water management system, however, is not necessarily recommended to be introduced if it is not already in place as it may deter SRI uptake. Working with the local farmers and their community to understand and develop local participatory irrigation systems is an essential step to inclusive, equitable, and sustainable development.

Mechanical Weeders

Investment in mechanical weeders requires capacity building through combined training and financial support in the necessary tools and equipment to manufacture rotary weeders.


CO_Shuichi Sato

Improved Equipment Supply Chains

Investments to enhance equipment supplies are necessary for faster scaled adoption for medium and large-scale farmers, and for those restricted by labour constraints.


CO_Biksham Gujja, AgSri

Insurance Schemes

Farmers may be concerned about receiving lower yields due to the initially counterintuitive nature of SRI practices. Agricultural insurance could help to alleviate this initial barrier and concern.


CO_Biksham Gujja, AgSri

Biomass Investments

Access to biomass of any source needs improvement. SRI education strategies should include training on sourcing and producing local biomass options.


CO_Biksham Gujja, AgSri

Training and Extension Officers

Investments in community capacity-building in the form of well-trained extension workers and lead farmers, who can demonstrate practices and support other farmer learning, are required to upscale SRI adoption. Extension work should reach both landowners and hired workers. Farmer Field Schools have been shown to be effective in spreading awareness and understanding of SRI practices.


CO_Biksham Gujja, AgSri

Dissemination Centres

Establishment of dissemination centres facilitates the creation of sustainable SRI networks, allowing farmers to receive support from extension officers and lead farmers.


CO_Shuichi Sato

Policy Lobbying

Investing in policy activism unites public, private, and civil sectors together to adopt SRI and achieve collective benefits. There is a lot of activity currently on the ground spreading awareness of SRI. But, in order to achieve potential levels of SRI production, policy-makers need to support and promote SRI practices.


CO_Biksham Gujja, AgSri

Further Research

Further context-specific research on adaptations of SRI can help find solutions to the contextual barriers to adoption. Monitoring and evaluation of projects is the most effective way of ensuring sustainability of SRI upscaling. Research demonstrating quantified benefits of combining SRI with other agroecological methodologies can help to foster a shift towards sustainable agricultural practices.

5. Weeding

Simple mechanical equipment is used to control weeds.

Avoiding flooded conditions fosters weed growth which needs to be kept under control. SRI farmers are encouraged to adopt simple mechanical weeders and start the operations 10 days after transplanting, repeating every 7-10 days until the canopy is closed. By incorporating the weeds into the soil, farmers enrich their field, they aerate the soil and they make nutrients newly available to the plant.

What further opportunities does SRI have?

SRI has been implemented in combination with other agroecological practices which also assist towards achieving the United Nations Sustainable Development Goals (SDGs).

Integrating SRI with agroforestry has been shown to improve yields and enhance carbon sequestration and also provides a source of organic matter.

SRI has been successfully incorporated into conservation agriculture (CA) in zero-till raised-bed rice production. Positive results have been demonstrated in China and Pakistan.

SRI is now included in multiple countries' National Climate Plans, both as an adaptation and mitigation technique.

SRI has also been included in disaster-preparedness programs to help vulnerable communities recover from the effects of natural disasters. Indonesia, for example, used SRI after the 2004 tsunami to help recover food production systems.

To halt the climate crisis and reverse warming trends, many practices that societies have followed for centuries call for change. The integration of climate-smart agricultural practices can assist moving rice cultivation into a sustainable system, necessary to mitigate global warming. Continual development and evaluation of agroecological approaches is necessary. Supporting the convergence of SRI, agroforestry, conservation agriculture, and other practices can help support farmers in producing climate-resilient crops, and play a crucial role in contributing to the achievement of multiple global sustainable development goals.