Van Eerd Laura L, Chahal Inderjot, Peng Yajun, Awrey Jessica C
School of Environmental Sciences, University of Guelph, Ridgetown, Ontario, Canada.
School of Environmental Sciences, University of Guelph, Ridgetown, Ontario, Canada.
Sci Total Environ. 2023 Feb 1;858(Pt 3):159990. doi: 10.1016/j.scitotenv.2022.159990. Epub 2022 Nov 7.
Cover crops have been studied for over a century, but the recognition of a complex interaction of cover crop on the Earth's biosphere, lithosphere, hydrosphere, and atmosphere is relatively recent. Furthermore, previously published cover crop research has largely focused on evaluating cover crop impacts on subsequent crop yield. Understanding the cover crop-induced benefits on soil organic carbon (SOC) sequestration, nitrous oxide (NO) emissions, wind and water erosion, weed control, and soil microbial communities has gained considerable attention in the last few decades, which is crucial to make progress towards developing sustainable agricultural production systems. New research is continuously published to gain a comprehensive understanding of the multiple ecosystem services provided by cover crops. Here, in this review, we aimed to (a) summarize current knowledge related to cover crop impacts on agroecosystem functioning and explore the potential mechanisms responsible for those effects, and (b) identify the key factors limiting the adoption of cover crops into agroecosystems and the conspicuous knowledge gaps in cover crop research. Overall, the review results suggest that cover crops increased subsequent crop yield, increased SOC storage, increased weed suppression, mitigated NO emissions, reduced wind and water erosion, suppressed plant pathogens, and increased soil microbial activity and wildlife biodiversity. However, the magnitude of benefits observed with cover crops varied with cover crop type, location, and the duration of cover cropping. Notably, cover crop termination methods, designing crop rotations to fit cover crops, additional costs associated with cover crop integration, and uncertainty related to economic returns with cover crops are some of the major barriers limiting the adoption of cover crops into production systems, particularly in North America. In addition to long-term effects, future research on cover crop agronomy, breeding cover crop cultivars, and interactive effects of cover crops with other sustainable land management practices is needed.
覆盖作物已经被研究了一个多世纪，但人们对覆盖作物在地球生物圈、岩石圈、水圈和大气圈中的复杂相互作用的认识相对较新。此外，先前发表的覆盖作物研究主要集中在评估覆盖作物对后续作物产量的影响。在过去几十年里，了解覆盖作物对土壤有机碳（SOC）固存、一氧化二氮（N₂O）排放、风蚀和水蚀、杂草控制以及土壤微生物群落的益处受到了相当大的关注，这对于在发展可持续农业生产系统方面取得进展至关重要。不断有新的研究发表，以全面了解覆盖作物提供的多种生态系统服务。在此综述中，我们旨在（a）总结与覆盖作物对农业生态系统功能影响相关的现有知识，并探索造成这些影响的潜在机制，以及（b）确定限制覆盖作物在农业生态系统中采用的关键因素和覆盖作物研究中明显的知识空白。总体而言，综述结果表明，覆盖作物提高了后续作物产量，增加了SOC储存，增强了杂草抑制能力，减少了N₂O排放，降低了风蚀和水蚀，抑制了植物病原体，并增加了土壤微生物活性和野生动物生物多样性。然而，覆盖作物所带来的益处程度因覆盖作物类型、地点和覆盖种植持续时间而异。值得注意的是，覆盖作物的终止方法、设计适合覆盖作物的作物轮作、与覆盖作物整合相关的额外成本以及与覆盖作物经济回报相关的不确定性是限制覆盖作物在生产系统中采用的一些主要障碍，特别是在北美。除了长期影响外，还需要对覆盖作物农艺学、培育覆盖作物品种以及覆盖作物与其他可持续土地管理实践的相互作用进行未来研究。
