Abstract Compost is a valuable organic amendment which affords substantive fertility to soils where applied. A common component of compost fertility is cation exchange capacity (CEC), which has traditionally been determined via standard wet chemistry laboratory methods. This research utilized portable X-ray fluorescence (PXRF) spectrometry to evaluate 74 compost samples from the USA and Canada. PXRF elemental data were used for predicting compost CEC via random forest (RF) regression. Comparison between laboratory-determined vs. PXRF predicted CEC produced the following relationships: R2=0.90, RMSE = 5.41 meq 100 g−1 (model calibration) and R2=0.60, RMSE = 8.07 meq 100 g−1 (model validation). A key advantage of this technique is that the same data used for CEC prediction can also yield insight into other compost parameters of interest such as heavy metal content, plant essential nutrient content, salinity, and pH. Taken collectively, the PXRF approach can provide rapid, on-site analysis of compost which was previously not feasible with conventional methods. Our initial study has established the viability of PXRF for compost CEC determination, with further development on a wider array of feedstocks suggested for future study.

中文翻译：

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通过便携式 X 射线荧光 (PXRF) 光谱法的堆肥阳离子交换能力

摘要 堆肥是一种有价值的有机改良剂，可在施用时为土壤提供大量肥力。堆肥肥力的一个常见组成部分是阳离子交换容量 (CEC)，传统上通过标准湿化学实验室方法确定。这项研究利用便携式 X 射线荧光 (PXRF) 光谱法来评估来自美国和加拿大的 74 个堆肥样品。PXRF 元素数据用于通过随机森林 (RF) 回归预测堆肥 CEC。实验室确定的与 PXRF 预测的 CEC 之间的比较产生以下关系：R2=0.90，RMSE = 5.41 meq 100 g-1（模型校准）和 R2=0.60，RMSE = 8.07 meq 100 g-1（模型验证）。该技术的一个关键优势是，用于 CEC 预测的相同数据还可以深入了解其他感兴趣的堆肥参数，例如重金属含量、植物必需营养素含量、盐度和 pH 值。总的来说，PXRF 方法可以提供对堆肥的快速现场分析，这在以前是传统方法不可行的。我们的初步研究确定了 PXRF 用于确定堆肥 CEC 的可行性，并进一步开发了更广泛的建议用于未来研究的原料。