This study makes the case for agroecological innovations in the current rice farming system to address the challenges of food and nutritional security, water scarcity, and soil degradation. In the review part of this study, the theoretical base for this case is made, using previous studies as reference. The vital interrelationships between such innovations and rural development and the Sustainable Development Goals (SDGs) were also established in this part. This is followed by a compilation of the results from the experimental studies that were conducted. Experiments were conducted first at greenhouse chamber level to establish the proof of concept for the relevance of the innovation of intercropping with rice under the System of Rice Intensification (SRI). This was followed by farmer-participative experiments at the field level to test for the scalability of the innovations and to test if intercropping brings the same benefits to rice farming system which it reportedly brings into other cropping systems.
The follow points highlight the main conclusions of this research:
1. Agroecological interventions like the System of Rice Intensification (SRI) and intercropping improve the environmental and economic productivity of rice farming.
2. The SRI has room for innovations which can make it an even better sustainable rice farming alternative.
3. Growing rice under the System of Rice Intensification with Beans Intercropping (SRIBI) improves its different plant growth characteristics and yield.
4. Intercropping (SRIBI) drastically reduces the weed infestation in rice plots grown under SRI regimen.
In the first batch of greenhouse level experiments, it was observed that intercropping resulted in an increase in different plant growth characteristics like plant height and tiller number. It was also observed that rice plants in the intercropping system, System of Rice Intensification with Beans Intercropping (SRIBI) showed higher nutrient uptake, especially nitrogen uptake, and showed a higher chlorophyll content in the leaves as compared to conventional flooded rice (CFR) cultivation as well as the normal SRI. The savings in water consumption and soil water retention in these experiments was also recorded. Further experiments were conducted to find the optimum time and spacing of the intercropped species with respect to the main crop. These aimed at a comparison of SRI and SRI with different configurations of intercropping. The
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results from the greenhouse experiments were used as the base to design experiments on the field scale.
In the field experiments, the focus of observation was the plant physical characteristics and the yield, to find out if intercropping would affect these characteristics of rice in comparison to SRI. The effect of intercropping on the incidence of weeds was also studied, as weeds are widely considered as a drawback of the SRI method and an increase in the labour requirements under SRI is also attributed to weeds. It was observed that intercropping led to an improvement in the physical growth characteristics of the plants in comparison to both SRI and CFR, despite only about 30% of the beans sown growing into plants. These included improvements in plant height and the spikelet number per panicle (SNPP), which increased by up to 20% and 50 % respectively in SRIBI compared to SRI. The tiller number in SRIBI was multiple times (up to 3 times) higher as compared to the conventionally grown rice. There was no significant difference observed in the grain weight between SRI and SRIBI. The 1000-grain weight was 26.24g and 25.46g for SRI and SRIBI respectively. However, in case of SRIBI, for every 100g of rice, 2.5g of beans was reported.
The marked difference between SRI and SRIBI was however observed in the incidence of weeds between the rows of rice. It was observed that intercropping led to a substantial reduction in weed population, which was clearly visible in the plots. A 77% reduction in the weed population was observed under intercropping as compared to the weed population in SRI, in absence of manual or chemical weeding after the date of intercropping.
The local aromatic rice variety (mushkbudij) which was used in the experimental studies is usually prone to rice blast in the ripening stages. However there was no incidence of the diseases in either SRI or SRIBI during the experimental trials, an aspect, that although needs deeper study, is definitely encouraging for the farmers. It was also observed that rice plots under SRI and SRIBI showed better resilience against rainstorms as compared to the neighbouring plots grown under conventional flooded rice (CFR) system.
These results suggest that intercropping legumes with rice under the System of Rice Intensification (SRI) has the potential to improve the ecological security of farming systems while at the same time improving the socio-economic situation of the farmers. This is evident from the improved growth characteristics, yield characteristics, resistance against weeds and extreme weather, and the possible improved resilience against diseases that was observed in
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these experiments. Such agroecological interventions need to followed up and continued in partnership and cooperation with farmers and organisations working on the ground.
Based on the theoretical and implementational research undertaken in the scope of this study, it can be concluded that SRI is a viable agroecological alternative to the current rice farming system, with a potential to improve the socioeconomic and ecological balance of the world food system. In view of the challenges like water scarcity, soil degradation, and increased occurrence of extreme weather events, SRI shows the required resilience, adaptation, and regeneration potential. Intercropping beans with rice under SRI is a valuable addition to the SRI method; it serves to diversify the income of the farmers and to reduce the biotic and abiotic stresses on the cropping system at the same time. SRIBI (System of Rice Intensification with Beans Intercropping) is hence proposed as an alternative sustainable rice cultivation method.
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RESEARCH OUTLOOK