Abstract

By storing carbon (C), soil provide natural solutions to climate change. However, implementing C sequestration practices on a large scale is complex because sequestration rates vary with climatic conditions, soil types and agricultural management. Researchers face challenges identifying effective C sequestration practices in arid and semi-arid regions because precipitation limits plant biomass production. We discuss the “more carbon per drop” approach to enhance C sequestration in a water-limited environment. This approach emphasizes increasing soil organic carbon (SOC) sequestration and reducing greenhouse gas emissions by enhancing water use efficiency and soil water storage. Agricultural strategies that increase the amount and diversity of C inputs, improve nutrient availability for crops, and minimize soil disturbance can simultaneously sequester soil C and enhance soil water storage. Strategies for enhancing SOC sequestration while increasing soil water storage could benefit farmers in arid and semi-arid regions because they can maintain a net-zero or net-negative C footprint. Therefore, implementing policies that promote SOC sequestration and soil water storage could provide natural climate solutions to the vast areas of the world facing water limitations.

• KEY POLICY HIGHLIGHTS

• SOC sequestration in a water-limited environment is challenging; more carbon per drop simultaneously increases SOC and soil water storage

• The social, economic, and cultural challenges of changing management practices for C sequestration could be addressed through a diverse set of incentives

• Incentivizing conventional SOC sequestration practices while investing in research and development of new frontier technologies could provide a win–win solution

摘要

通过储存碳 (C)，土壤为气候变化提供了自然解决方案。然而，大规模实施碳封存实践是复杂的，因为封存率随气候条件、土壤类型和农业管理而变化。由于降水限制了植物生物量的生产，研究人员面临着在干旱和半干旱地区确定有效碳封存实践的挑战。我们讨论了“每滴碳更多”的方法，以在水资源有限的环境中增强 C 封存。这种方法强调通过提高水利用效率和土壤蓄水量来增加土壤有机碳 (SOC) 封存和减少温室气体排放。增加碳投入量和多样性、改善作物养分供应的农业战略，和最大限度地减少土壤干扰可以同时隔离土壤碳并增强土壤储水量。在增加土壤蓄水的同时加强 SOC 封存的策略可以使干旱和半干旱地区的农民受益，因为他们可以保持净零或净负的碳足迹。因此，实施促进 SOC 封存和土壤蓄水的政策可以为世界上面临水资源限制的广大地区提供自然气候解决方案。

• 主要政策亮点

• 在水资源有限的环境中封存 SOC 具有挑战性；每滴更多的碳同时增加 SOC 和土壤储水量

• 改变碳封存管理实践所带来的社会、经济和文化挑战可以通过一系列不同的激励措施来解决

• 激励传统的 SOC 封存做法，同时投资于新前沿技术的研发，可以提供双赢的解决方案