Conservation agriculture effects on ecosystem health and sustainability - A review of rice-wheat cropping system.

Conventional tillage, extreme climate events, increasing weed incidence, pest and disease pressures, and diminished farm input availability negatively impact crop yield, stability, profitability, and water productivity in South Asia's rice-wheat (R-W) systems. This article reviews and evaluates the effectiveness and benefits of conservation agriculture (CA) practices in improving soil health, water productivity, and sustainability in R-W systems. CA practices focus on minimum soil disturbance, permanent soil cover, and crop rotations. Techniques such as direct seeding in rice and zero tillage in wheat are employed, supported by advancements in zero tillage sowing machinery like super-seeders. CA practices contribute significantly to ecosystem health by conserving soil and water, enhancing soil quality, reducing erosion, and improving nutrient use efficiency. They also lower production costs, increase water use efficiency, stabilize yields, promote crop diversification, and mitigate climate change effects through carbon sequestration and reduced greenhouse gas emissions. However, initial challenges include increased weed pressure and the need for suitable rice varieties for direct seeding. In conclusion, CA practices support sustainable and climate-resilient farming, improving land and water productivity, food security, and on-farm profits. Despite the benefits and growing government support, widespread adoption in South Asia remains limited. Effective support systems, including incentives, technical knowledge dissemination, and integrated weed management, are crucial for overcoming barriers and enhancing CA adoption in R-W systems.