土壤有机碳估算的最佳采样和分析方法
Optimal sampling and assay for soil organic carbon estimation
摘要：
世界需要约150 Pg的负碳排放来减缓气候变化。全球土壤可以提供一个稳定的，相当大的水库，以帮助实现这一目标，通过隔离大气中的二氧化碳作为土壤有机碳（SOC）。反过来，SOC可以支持健康的土壤，并提供多种生态系统效益。为了支持SOC固存，研究人员和政策制定者必须能够精确测量给定地块中的SOC数量。SOC测量通常通过从研究地块中随机选择土芯，将其中一些混合（合成）在一起，并在实验室中分析（测定）合成样品来完成。复合降低了分析成本，这可能是相当大的。取样也很昂贵。给定采样和测定中的不确定性和成本以及期望的估计精度，存在最佳复合尺寸，其将使实现该精度所需的预算最小化。相反，给定一个固定的预算，有一个综合规模，最大限度地减少不确定性。在本文中，我们描述和形式化的采样和分析SOC和推导出最佳的三种常用的分析方法：干燃烧元素分析仪，烧失量，和中红外光谱。我们证明了这种方法的实用性，从土壤调查在加利福尼亚州进行的数据。我们提供实践建议，并提供软件来实现我们的框架。
英文摘要：
The world needs around 150 Pg of negative carbon emissions to mitigate climate change. Global soils may provide a stable, sizeable reservoir to help achieve this goal by sequestering atmospheric carbon dioxide as soil organic carbon (SOC). In turn, SOC can support healthy soils and provide a multitude of ecosystem benefits. To support SOC sequestration, researchers and policy makers must be able to precisely measure the amount of SOC in a given plot of land. SOC measurement is typically accomplished by taking soil cores selected at random from the plot under study, mixing (compositing) some of them together, and analyzing (assaying) the composited samples in a laboratory. Compositing reduces assay costs, which can be substantial. Taking samples is also costly. Given uncertainties and costs in both sampling and assay along with a desired estimation precision, there is an optimal composite size that will minimize the budget required to achieve that precision. Conversely, given a fixed budget, there is a composite size that minimizes uncertainty. In this paper, we describe and formalize sampling and assay for SOC and derive the optima for three commonly used assay methods: dry combustion in an elemental analyzer, loss-on-ignition, and mid-infrared spectroscopy. We demonstrate the utility of this approach using data from a soil survey conducted in California. We give recommendations for practice and provide software to implement our framework.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
