"System of Rice Intensification" of cultivation, in which alternate wetting and drying of rice fields is practised, results in : Select the correct answer using the code given below :
1 , 2 and 3
Understanding the System of Rice Intensification (SRI)
The System of Rice Intensification (SRI) is a methodology for increasing the yield of rice produced in farming. It involves changes in managing the plants, soil, water, and nutrients. One key practice within SRI is the alternate wetting and drying (AWD) of the rice fields.
Benefits of Alternate Wetting and Drying in Rice Cultivation
The question asks about the specific results of practicing alternate wetting and drying within the System of Rice Intensification. Let's examine each point mentioned in the options:
1. Reduced Seed Requirement in SRI
The System of Rice Intensification promotes transplanting young seedlings, often singly and widely spaced, rather than broadcasting large quantities of seeds or planting multiple seedlings per hill. This method significantly reduces the total amount of seed needed compared to conventional rice farming methods where dense seeding is common. Therefore, reduced seed requirement is a direct result of adopting SRI principles.
- SRI focuses on planting single, young seedlings.
- Seedlings are spaced further apart.
- This contrasts with conventional methods using higher seed rates.
2. Reduced Methane Production in Rice Fields
Methane is a potent greenhouse gas produced in flooded rice fields by anaerobic bacteria decomposing organic matter. Alternate wetting and drying (AWD) is a core practice in SRI that involves periodically draining the rice field, allowing the soil to dry slightly before re-flooding it. This intermittent drying introduces oxygen into the soil, which inhibits the activity of the methane-producing anaerobic bacteria. This leads to a significant reduction in methane emissions compared to continuously flooded rice fields.
- Flooded fields create anaerobic conditions suitable for methane-producing bacteria.
- AWD introduces aerobic conditions temporarily.
- Oxygen inhibits methane production.
3. Reduced Electricity Consumption for Irrigation
Alternate wetting and drying involves less continuous flooding compared to traditional methods that keep the fields submerged throughout the growing season. Since less water is needed overall and the field is not kept permanently flooded, the demand for pumping water (often using electric pumps) is reduced. This directly translates to lower electricity consumption for irrigation purposes.
- AWD uses less water than continuous flooding.
- Reduced water use means less pumping is required.
- Less pumping leads to lower electricity usage.
Conclusion on SRI Benefits
Based on the analysis of each point, the System of Rice Intensification, particularly with the practice of alternate wetting and drying, results in:
- Reduced seed requirement (due to single, spaced transplanting).
- Reduced methane production (due to intermittent drying).
- Reduced electricity consumption (due to less water pumping).
Therefore, all three statements are accurate results of adopting the System of Rice Intensification with alternate wetting and drying.
| SRI Practice (AWD) | Impact | Explanation |
|---|---|---|
| Single, young seedling transplanting | Reduced seed requirement | Less seed is needed per unit area. |
| Alternate wetting and drying (AWD) | Reduced methane production | Periodic drying introduces oxygen, inhibiting methane bacteria. |
| Less water application (AWD) | Reduced electricity consumption | Less pumping of water is needed for irrigation. |
Revision Table: Key Outcomes of SRI with AWD
| Aspect | SRI Result |
|---|---|
| Seed | Lower requirement |
| Methane Emissions | Reduced |
| Water Use | Reduced |
| Energy for Irrigation | Reduced electricity consumption |
| Yield | Often increased |
Additional Information on System of Rice Intensification
The System of Rice Intensification (SRI) is not just about alternate wetting and drying, but a set of practices that aims to improve soil health, plant health, and yield while using fewer external inputs like water and seeds. Key principles include:
- Using very young seedlings for transplanting (usually 8-15 days old).
- Transplanting seedlings singly rather than in clumps.
- Wider spacing between plants in a square grid pattern.
- Maintaining moist soil conditions rather than continuous flooding, often using Alternate Wetting and Drying (AWD).
- Using organic fertilizers and improving soil health.
- Weeding actively, often using mechanical methods which also aerate the soil.
These combined practices in SRI lead to stronger plants with larger root systems, which can access nutrients and water more effectively, often resulting in higher yields along with the resource savings mentioned in the question.
