In the vast, often unforgiving landscapes of saline-alkali soils, farmers face an uphill battle to grow crops while minimizing environmental impact. A groundbreaking study led by Fangdi Chang, from the State Key Laboratory of Efficient Utilization of Arable Land in China and the College of Agronomy and Biotechnology at China Agricultural University, offers a promising solution to this challenge. The research, published in ‘Resources, Environment and Sustainability’ (which translates to ‘资源、环境与可持续发展’), delves into the intricate dance between nitrogen fertilizer use, green manure, and nitrous oxide (N2O) emissions in spring wheat cultivation.
The study, spanning from 2020 to 2024, explored the effects of varying nitrogen fertilizer application rates combined with green manure return strategies on wheat yield, yield stability, and N2O emissions. The findings are nothing short of transformative. “We found that reducing nitrogen fertilizer by 20% and returning only the roots of green manure can maintain spring wheat yield while significantly decreasing N2O emissions,” Chang explains. This is a game-changer for farmers and the energy sector alike, as N2O is a potent greenhouse gas with a global warming potential 300 times greater than carbon dioxide.
The research revealed that while nitrogen fertilizer combined with green manure return strategies increased wheat yield by 8% to 22%, it also decreased yield stability. However, the real breakthrough came with the discovery that reducing nitrogen fertilizer by 20% (from 200 kg N ha-1 to 160 kg N ha-1) and returning only the roots of green manure decreased cumulative soil N2O emissions by 20% to 34% and N2O intensity by 22% to 38% compared to returning both roots and shoots. This strategy not only mitigates the environmental impact but also offers economic benefits by reducing the amount of nitrogen fertilizer needed.
For the energy sector, this research holds significant implications. As the world transitions towards cleaner energy sources, understanding and mitigating agricultural N2O emissions become crucial. The findings suggest that by adopting more sustainable farming practices, the agricultural sector can contribute to global efforts to reduce greenhouse gas emissions. This could potentially open avenues for carbon credits and other incentives for farmers, creating a win-win situation for both the environment and the economy.
The study also highlights the importance of soil pH and NO3−-N content in regulating N2O emissions in saline-alkali soils. This knowledge can guide future research and policy decisions aimed at optimizing nitrogen use and minimizing environmental impact in similar agroecosystems.
As we look to the future, this research paves the way for more sustainable and efficient agricultural practices. By integrating green manure return strategies with optimized nitrogen fertilizer use, farmers can enhance crop productivity while mitigating climate change. The findings underscore the need for continued innovation and research in agritech, as well as the importance of policy support to incentivize sustainable farming practices. The energy sector, in particular, stands to benefit from these advancements, as reducing agricultural N2O emissions can help meet global climate goals and foster a more sustainable future.