Widespread adoption of regenerative agriculture practices is an integral part of the US plan to achieve net-zero greenhouse gas emissions by 2050. National incentives have particularly increased for the adoption of cover crops (CCs), which have presumably large carbon (C) sequestration potential. However, assessments of national CC climate benefits have not fully considered regional variability, changing C sequestration rates over time, and potential N₂O trade-offs. Using the DayCent soil biogeochemical model and current national survey data, we estimate CC climate change mitigation potential to be 39.0 ± 24.1 Mt CO₂e year⁻¹, which is 45%–65% lower than previous estimates, with large uncertainty attributed to N₂O impacts. Three-fourths of this climate change mitigation potential is concentrated in the North Central, Southern Great Plains and Lower Mississippi regions. Public investment should be focused in these regions to maximize CC climate benefits, but the national contribution of CC to emissions targets may be lower than previously anticipated.

中文翻译：

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美国覆盖作物的气候缓解潜力集中于区域，低于之前的估计


广泛采用再生农业实践是美国到 2050 年实现温室气体净零排放计划的一个组成部分。国家对覆盖作物 (CC) 的采用的激励措施尤其增加，这些作物可能具有巨大的碳 (C) 固存潜力。然而，对国家CC气候效益的评估并未充分考虑区域变异性、随时间变化的碳封存率以及潜在的N ₂ O权衡。利用 DayCent 土壤生物地球化学模型和当前国家调查数据，我们估计 CC 气候变化减缓潜力为 39.0 ± 24.1 Mt CO ₂ e 年 ⁻¹ ，即 45%–65%低于之前的估计，N ₂ O 影响具有很大的不确定性。四分之三的气候变化减缓潜力集中在中北部、大平原南部和密西西比河下游地区。公共投资应集中在这些地区，以最大限度地提高 CC 的气候效益，但 CC 对排放目标的国家贡献可能低于之前的预期。