System of Rice Intensification

The System of Rice Intensification (SRI) is an innovative and sustainable method of rice cultivation that aims to increase yields while reducing inputs such as water, seeds, and chemical fertilisers. Developed through farmer experimentation in Madagascar during the 1980s, SRI represents a major shift from traditional paddy cultivation practices by focusing on optimising plant, soil, water, and nutrient management rather than depending solely on external inputs.

Origin and Development

The System of Rice Intensification was developed in Madagascar by Father Henri de Laulanié, a French Jesuit priest and agricultural scientist. Through practical observation and experimentation with local farmers in the 1980s, he identified techniques that enhanced rice plant growth by improving root development and soil aeration.
The method was later promoted by the Association Tefy Saina, a non-governmental organisation in Madagascar, and gained international attention through the efforts of Norman Uphoff of Cornell University in the 1990s.
By the early 2000s, SRI had spread to countries across Asia, Africa, and Latin America, becoming an important part of discussions on sustainable agriculture, particularly in nations facing challenges of water scarcity and land degradation.

Principles and Practices of SRI

The System of Rice Intensification is not a fixed technology but a set of principles and practices that can be adapted to local conditions. Its core components are based on improving the biological efficiency of rice plants and the ecosystems in which they grow.
The key practices include:

• Young Seedling Transplanting:Seedlings are transplanted at an early age, typically between 8 and 12 days old, when they have just two small leaves. This early transplantation helps minimise transplant shock and promotes vigorous root growth.
• Single Seedling per Hill:Instead of clumps of multiple seedlings, only one seedling is planted per hill, allowing each plant sufficient space and resources to grow to its full potential.
• Wider Spacing:Plants are spaced at wider intervals, usually in a square pattern (25 × 25 cm) or even wider, to enable better sunlight penetration and air circulation. This spacing also facilitates mechanical weeding and soil aeration.
• Alternate Wetting and Drying:Fields are kept moist but not continuously flooded, unlike traditional methods. Periodic drying allows soil aeration, encouraging microbial activity and stronger root systems.
• Mechanical Weeding and Soil Aeration:Weeds are controlled using cono weeders or mechanical devices that also help to aerate the soil, improving root respiration and nutrient uptake.
• Use of Organic Manure:Preference is given to compost, farmyard manure, or green manure over chemical fertilisers to enhance soil health and microbial diversity.

These principles combine to create a more productive and environmentally friendly system of rice cultivation.

Agronomic and Ecological Benefits

The SRI method has been shown to bring about several measurable benefits in terms of yield, input efficiency, and environmental sustainability:

• Higher Yields: Rice yields can increase by 30 to 50 per cent compared with traditional flooded methods, even under resource-poor conditions.
• Reduced Water Use: SRI typically requires 30 to 40 per cent less water, as fields are not kept continuously flooded.
• Lower Seed Requirement: Because single seedlings are used, the seed requirement is reduced by up to 80–90 per cent.
• Improved Soil Health: Periodic drying and the use of organic matter promote soil aeration, beneficial microorganisms, and long-term fertility.
• Reduced Methane Emissions: Less flooding results in reduced anaerobic conditions, thereby lowering methane emissions—a significant greenhouse gas.
• Enhanced Plant Vigour: SRI plants develop stronger root systems and thicker tillers, making them more resistant to pests, diseases, and climatic stresses such as drought or storm damage.

Implementation and Adoption in India

In India, the SRI method was introduced in the early 2000s, with the state of Tamil Nadu being one of the first to adopt it widely. The Directorate of Rice Research and the National Bank for Agriculture and Rural Development (NABARD) supported pilot projects to promote the technique.
Major states practising SRI today include Andhra Pradesh, Bihar, Odisha, Tamil Nadu, West Bengal, and Tripura. The Government of India has integrated SRI promotion into schemes such as the National Food Security Mission (NFSM) and Rashtriya Krishi Vikas Yojana (RKVY).
Field demonstrations, training for farmers, and the provision of simple mechanical weeders have played a key role in expanding SRI cultivation across the country.

Challenges and Limitations

Despite its numerous advantages, the widespread adoption of SRI faces several challenges:

• Labour Intensity: The need for careful transplanting of young seedlings and frequent weeding increases labour demand, especially at the initial stages.
• Knowledge Requirement: SRI involves management-intensive practices that require training and consistent observation. Many farmers find it difficult to adopt without guidance.
• Water Control Difficulties: Maintaining alternate wetting and drying requires precise control over irrigation, which is not always feasible in canal-irrigated or rainfed systems.
• Initial Yield Variability: In some cases, inconsistent application of SRI principles has led to mixed results, discouraging smallholders from continuing.

Scientific and Environmental Significance

The System of Rice Intensification is an example of agroecological innovation—enhancing productivity by working with natural processes rather than relying heavily on external chemical inputs. Its scientific foundation lies in optimising root health, soil biology, and plant-microbe interactions.
By promoting sustainable water use and reducing greenhouse gas emissions, SRI also contributes to climate change mitigation and adaptation strategies. In regions prone to water scarcity, such as South and Southeast Asia, SRI offers a viable method for producing more rice with less environmental impact.

Global Impact and Adaptations

SRI has now spread to over 50 countries, including China, Indonesia, Vietnam, the Philippines, Ethiopia, and Cuba. It has also inspired similar innovations for other crops such as wheat, sugarcane, and finger millet—collectively known as System of Crop Intensification (SCI).
These adaptations follow the same core principle of improving productivity through enhanced plant and soil management rather than increased external input use.