Over the last few years, the question of whether soil carbon sequestration could contribute significantly to climate change mitigation has been the object of numerous debates. All of these debates so far appear to have entirely overlooked a crucial aspect of the question. It concerns the short-term mineralization kinetics of fresh organic matter added to soils, which is occasionally alluded to in the literature, but is almost always subsumed in a broader modelling context. In the present article, we first summarise what is currently known about the kinetics of mineralization of plant residues added to soils, and about its modelling in the long run. We then argue that in the short run, this microbially-mediated process has important practical consequences that cannot be ignored. Specifically, since at least 90% of plant residues added to soils to increase their carbon content over the long term are mineralized relatively rapidly and are released as CO₂ to the atmosphere, farmers would have to apply to their fields 10 times more organic carbon annually than what they would eventually expect to sequester. Over time, because of a well-known sink saturation effect, the multiplier may even rise significantly above 10, up to a point when no net carbon sequestration takes place any longer. The requirement to add many times more carbon than what one aims to sequester makes it practically impossible to add sufficient amounts of crop residues to soils to have a lasting, non-negligible effect on climate change. Nevertheless, there is no doubt that raising the organic matter content of soils is desirable for other reasons, in particular guaranteeing that soils will be able to keep fulfilling essential functions and services in spite of fast-changing environmental conditions.

中文翻译：

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用于减缓气候变化的土壤碳封存：有机投入物的矿化动力学是一个被忽视的限制

在过去的几年里，土壤碳封存是否可以显着促进减缓气候变化的问题一直是众多争论的主题。到目前为止，所有这些辩论似乎都完全忽略了这个问题的一个关键方面。它涉及添加到土壤中的新鲜有机物的短期矿化动力学，这在文献中偶尔会提到，但几乎总是包含在更广泛的建模环境中。在本文中，我们首先总结了目前已知的关于添加到土壤中的植物残留物的矿化动力学及其长期建模的知识。然后我们认为，在短期内，这种微生物介导的过程具有不可忽视的重要实际后果。具体来说，₂对大气而言，农民每年向他们的田地施用的有机碳将是他们最终预计的封存量的 10 倍。随着时间的推移，由于众所周知的汇饱和效应，乘数甚至可能显着高于 10，直至不再发生净碳固存。需要添加比封存目标多许多倍的碳，这使得在土壤中添加足够量的作物残留物以对气候变化产生持久的、不可忽视的影响几乎是不可能的。然而，毫无疑问，出于其他原因，提高土壤的有机质含量是可取的，特别是保证土壤能够在快速变化的环境条件下继续履行基本功能和服务。