Bioscience Evidence 2024, Vol.14, No.6, 270-280 http://bioscipublisher.com/index.php/be 276 8 Case Studies in High-Yield Rice Cultivation 8.1 Case study: high-yield rice varieties in southeast Asia In Southeast Asia, the introduction of high-yield rice varieties has been pivotal in addressing food security challenges exacerbated by climate change. A multi-scale crop modeling approach was employed to assess the impacts of climate change on rice yields and to develop adaptation strategies. The study identified Cambodia as the most vulnerable country, with potential yield reductions of up to 45% by the 2080s under high-emission scenarios. However, improved irrigation practices could significantly mitigate these losses, increasing yields by up to 42.7% in some regions (Chun et al., 2016). Additionally, the adoption of appropriate agronomic practices, such as optimized seeding and nitrogen rates, has been shown to improve yield, water productivity, and nitrogen use efficiency in wet direct-seeded rice systems (Santiago-Arenas et al., 2021). These findings underscore the importance of integrating advanced agronomic practices and climate adaptation strategies to sustain rice production in Southeast Asia. 8.2 Case study: sustainable yield strategies in India In India, sustainable yield strategies have been implemented to enhance rice productivity while minimizing environmental impacts. In the Eastern Gangetic Plains, conservation agriculture-based sustainable intensification practices have been tested across various cropping systems. These practices significantly reduced energy use and CO2-equivalent emissions while increasing energy use efficiency and net income for farmers (Gathala et al., 2020). Furthermore, in the northeastern Himalayas, improved agronomic practices and high-yielding rice varieties have been shown to maintain soil health and enhance yield and energy use efficiency. Farmers' participatory field trials demonstrated that improved practices, such as line-sowing and the application of farmyard manure, significantly increased rice yields and improved soil fertility compared to traditional shifting cultivation methods (Layek et al., 2023). These sustainable yield strategies highlight the potential for agronomic innovations to improve rice productivity and environmental sustainability in India. 8.3 Lessons learned from case studies The case studies from Southeast Asia and India provide several key lessons for high-yield rice cultivation. The use of multi-scale crop modeling to develop national and farmer-level adaptation strategies is crucial for mitigating the adverse effects of climate change on rice yields. Improved irrigation and optimized agronomic practices can significantly enhance yield resilience (Chun et al., 2016; Santiago-Arenas et al., 2021). Conservation agriculture and sustainable intensification practices can reduce energy use and greenhouse gas emissions while increasing productivity and profitability. These practices are particularly effective in regions with high climate variability (Gathala et al., 2020). Maintaining soil health through improved agronomic practices, such as line-sowing and the use of organic fertilizers, is essential for sustaining high yields. Participatory approaches involving local farmers can ensure the successful adoption of these practices. The introduction of high-yield rice varieties, coupled with appropriate agronomic management, can significantly boost productivity. This approach is particularly effective in regions with challenging growing conditions, such as the northeastern Himalayas (Layek et al., 2023). 9 Challenges and Limitations in Achieving High Yields 9.1 Environmental and climate challenges Environmental and climate factors significantly impact rice yields. Climate change has led to variations in potential yields across different regions. For instance, in the Middle and Lower Reaches of the Yangtze River (MLRYR), potential rice yields have either declined or remained stagnant, while in the Northeastern China Plain (NECP), they have shown slight increases or stability over the years. Additionally, climate-induced water stress is a major limiting factor in both regions, affecting the overall productivity of rice crops (Zhang et al., 2019). In sub-Saharan Africa (SSA), future productivity is threatened by climate change, water shortages, and soil degradation, which further complicate efforts to increase rice yields (Nhamo et al., 2014). The inherent soil properties also play a crucial role, as they can limit rice yields more than previously understood, necessitating optimized crop and soil management practices to mitigate these effects (An et al., 2015).
RkJQdWJsaXNoZXIy MjQ4ODYzMg==