The System of Rice Intensification (SRI) is a farming approach designed to boost rice production yields. This system in rice cultivation is developed by Fr. Hennery De Laulani along with the farmers of Madagascar in 1982. In this system, young rice seedlings are planted in wider spacing to allow greater realization of tillering potential and also to provide more space for the roots to grow.
Principles of SRI
- Transplanting of Single seedling per hill
- Reduces competition among seedlings and minimizes the shading effect on lower leaves.
- Increase in root length and density.
- Transplanting young seedlings (12-14 days old)
- Endosperm remains attached with roots helps to minimize transplanting stress
- Younger seedlings have high tillering capacity. i.e. up to 80-100 tillers/plant.
- Better crop establishment, higher yields, and reduced pest and disease incidence
- Transplanting of seedlings into a moist field (not too wet as in the conventional method)
- Shallow transplanting is done. i.e. 1-2 cm.
- Drained condition of the field enhances root respiration and hence root activity.
- Planting of seedlings in wider spacing
- Spacing is maintained 25-30 cm × 25-30 cm or more (sometimes 40 cm ×40 cm)
- Allows roots to grow abundantly and hence there are a greater number of tillers per plant, leading to stronger and healthier plants.
- Better interception of sunlight by the plant.
- Alternate wetting and drying (AWD) of the field
- AWD is done based on the availability of soil moisture. i.e. wetting of field for 2-3 days and then drying for about 5-7 days depending upon soil type.
- Helps to improve oxygen supply to the roots and also improves soil properties resulting in vigorous growth of roots.
- Mechanical weeding
Weeding is done early and frequently (3 to 4 times) as the weed occurs more and germinates faster.
- Use of organic manure instead of chemical fertilizer
Organic manures help to improve the physical, chemical, and biological properties of the soil and hence improve the growth and development of the crop.
Advantages of SRI
- Water requirement of the rice crop is reduced by 25-50 %. (at least 25-30 %).
- Seed requirement is less. i.e. only 8-10 kg seed is required to transplant in one-hectare land.
- The crop matures 10-20 days earlier as young seedlings with high tillering capacity are transplanted.
- Due to the longer and healthier roots of the rice plants under SRI, the plants are relatively drought-resistant.
- Soil health improves through biological activity
- Yield increased by 2-3 folds due to vigorous crop growth, better nutrient uptake, better light interception, and fewer insects and diseases. i.e. about 8-9 t/ha yield.
- As the crop is grown with wider spacing and in moist soil conditions, more weed problems should be managed properly.
Challenges
- SRI often requires more labor, especially in the early stages of implementation, such as during transplanting and weeding
- Not suitable when no irrigation source is available
- Farmers need training to properly implement SRI techniques, and adoption rates can be slow due to the required changes in traditional farming practices.
The System of Rice Intensification (SRI) is not a rigid or standardized technological approach. Instead, it represents a collection of ideas and methods aimed at efficiently managing and conserving resources by altering the way that land, seeds, water, nutrients, and human labour are used in order to increase productivity.