John Muir Institute of the Environment, University of California, Davis, California.
Cary Institute of Ecosystem Studies, Millbrook, New York.
Ann N Y Acad Sci. 2021 Dec;1505(1):102-117. doi: 10.1111/nyas.14690. Epub 2021 Sep 27.
Soil carbon (C) sequestration in agricultural working lands via soil amendments and management practices is considered a relatively well-tested and affordable approach for removing CO from the atmosphere. Carbon farming provides useful benefits for soil health, biomass production, and crop resilience, but the effects of different soil C sequestration approaches on the nitrogen (N) cycle remain controversial. While some C farming practices have been shown to reduce N fertilizer use in some cases, C farming could also impose an unwanted "N penalty" through which soil C gains can only be maintained with additional N inputs, thereby increasing N losses to the environment. We systematically reviewed meta-analysis studies on the impacts of C farming on N cycling in agroecosystems and estimated the cumulative effect of several C farming practices on N cycling. We found that, on average, combined C farming practices significantly reduced nitrous oxide emissions and nitrate leaching from soils, thus inferring both N cycling and climate change benefits. In addition to more widely studied C farming practices that generate organic C, we also discuss silicate rock additions, which offer a pathway to inorganic C sequestration that does not require additional N inputs, framing important questions for future research.
通过土壤改良和管理措施在农业用地上固存土壤碳（C）被认为是一种相对经过充分测试且经济实惠的方法，可以将 CO 从大气中去除。碳农业为土壤健康、生物质生产和作物抗逆性提供了有益的好处，但不同土壤 C 固存方法对氮（N）循环的影响仍存在争议。虽然一些 C 农业实践已被证明在某些情况下可以减少 N 肥的使用，但 C 农业也可能通过“N 惩罚”施加不必要的影响，即只有通过额外的 N 投入才能维持土壤 C 的增加，从而增加 N 向环境的损失。我们系统地回顾了关于 C 农业对农业生态系统中 N 循环影响的荟萃分析研究，并估计了几种 C 农业实践对 N 循环的累积影响。我们发现，平均而言，综合 C 农业实践显著减少了土壤中一氧化二氮的排放和硝酸盐淋失，从而推断出 N 循环和气候变化的好处。除了更广泛研究的产生有机 C 的 C 农业实践外，我们还讨论了添加硅酸盐岩石，这为不需要额外 N 投入的无机 C 固存提供了一种途径，为未来的研究提出了重要问题。
