Abstract. We evaluated the performance of a new, simple test to evaluate soil structural stability. The QuantiSlakeTest (QST) consists in a quantitative approach of the slake test, a dynamic weighing of a dried structured soil sample once immersed in water. The objective of this work was threefold: we aimed to (i) derive indicators from QST curves to evaluate soil structural stability, (ii) establish the relationship between soil properties and QST indicators, and (iii) assess how QST indicators respond to contrasting soil management practices. To reach these goals, we sampled the soil of 35 plots from three long-term field trials in the silt loam region of Belgium dealing respectively with contrasting organic matter inputs, tillage and P–K fertilisation. For each plot, indicators calculated from QST curves (e.g. total relative mass loss, disaggregation speed and time to meet a threshold values of mass loss) were compared to the results of the three tests of Le Bissonnais (1996), used as a reference method for the measurement of soil aggregate stability. Shortly after immersion in water, soil mass increases due to the rapid replacement of air by water in soil porosity. Then soil mass reaches a maximum before decreasing, once mass loss by disaggregation exceeds mass gain by air loss. Our results confirmed that the early mass loss under water is mainly related to slaking, whereas after a longer time period, clay dispersion and differential swelling become the dominant processes of soil disaggregation. The overall soil structural stability was positively correlated to the soil organic carbon (SOC) content and negatively correlated to the clay content of soil. Consequently, the SOC : clay ratio was closely related to QST indicators. Nevertheless, for a similar mean annual carbon (C) input, green manure and crop residues were more efficient in decreasing clay dispersivity and differential swelling, whereas farmyard manure promoted SOC storage and was more efficient against slaking. QST curves had a strong discriminating power between reduced tillage and ploughing regardless of the indicator, as reduced tillage increases both total SOC content and root biomass in the topsoil. The QST has several advantages. It (i) is rapid to run, (ii) does not require expensive equipment or consumables, and (iii) provides a high density of information on both specific mechanisms of soil disaggregation and the overall soil structural stability. As an open-access programme for QST data management is currently under development, the test has a strong potential for adoption by a widespread community of end users.

中文翻译：

---

QuantiSlakeTest，通过动态称重浸入水中的未受干扰样品来测量土壤结构稳定性

摘要。我们评估了一种新的、简单的测试来评估土壤结构稳定性的性能。QuantiSlakeTest (QST) 是一种定量的淤泥测试方法，即对浸入水中的干燥结构化土壤样品进行动态称重。这项工作的目标有三个：我们的目的是 (i) 从 QST 曲线得出指标来评估土壤结构稳定性，(ii) 建立土壤特性和 QST 指标之间的关系，以及 (iii) 评估 QST 指标对对比土壤的反应管理实践。为了实现这些目标，我们在比利时淤泥质壤土地区进行了三个长期田间试验，对 35 个地块的土壤进行了采样，分别处理对比有机质投入、耕作和磷钾肥。对于每个图，将根据 QST 曲线计算的指标（例如总相对质量损失、解聚速度和达到质量损失阈值的时间）与 Le Bissonnais (1996) 的三个测试结果进行比较，用作参考方法用于测量土壤团聚体稳定性。浸入水中后不久，由于土壤孔隙中的空气迅速被水取代，土壤质量增加。一旦分解造成的质量损失超过空气损失造成的质量增加，土壤质量就会在减少之前达到最大值。我们的结果证实，水下的早期质量损失主要与熟化有关，而经过较长时间后，粘土分散和差异膨胀成为土壤解聚的主要过程。土壤整体结构稳定性与土壤有机碳（SOC）含量呈正相关，与土壤粘土含量呈负相关。因此，SOC：粘土比率与 QST 指标密切相关。然而，对于相似的年平均碳（C）输入，绿肥和农作物残留物在降低粘土分散性和差异膨胀方面更有效，而农家肥则促进 SOC 储存并更有效地防止熟化。无论指标如何，QST 曲线在减少耕作和犁耕之间都具有很强的区分能力，因为减少耕作会增加表土中的总 SOC 含量和根系生物量。QST 有几个优点。它（i）运行速度快，（ii）不需要昂贵的设备或消耗品，（iii）提供有关土壤分解的具体机制和整体土壤结构稳定性的高密度信息。由于 QST 数据管理的开放获取程序目前正在开发中，因此该测试具有被广泛的最终用户社区采用的巨大潜力。