The successful implementation of sustainable resource management strategies depends on the availability of indicators that are capable of reflecting system complexity adequately but can easily be computed and communicated. However, systematic assessment of the scope and limits of simple indicators is often lacking. In the present study two indicators that can readily be derived from a material flow analysis structure are applied to and evaluated in a large and complex system of phosphorus and nitrogen management in Austria. Circularity (C) is defined as the share of recycled materials in total system throughput, whereas the Substance Concentration Efficiency (SCE), an indicator based on statistical entropy, measures the extent to which a substance is concentrated or diluted while passing through the system. For comparison the indicators were normalized with respect to a best-case and worst-case scenario ($\overline{C}$ and $\overline{SCE}$). Although both indicators correspond well in their general statements, clear differences in the prioritization of different aspects of sustainability can be observed. While $\overline{C}$ focuses on increasing recycling, emission reduction and system downsizing have stronger effects on $\overline{SCE}$. $\overline{SCE}$ therefore is considered more suitable for providing first indications on sustainability in Austrian nutrient management.

可持续资源管理策略的成功实施取决于指标的可用性，这些指标能够充分反映系统的复杂性，但可以轻松地进行计算和传达。但是，经常缺乏对简单指标的范围和界限的系统评估。在本研究中，可以从奥地利的大型复杂磷和氮管理系统中应用和评估可以从物质流分析结构中轻松得出的两个指标。圆度（C）定义为再生材料在系统总吞吐量中所占的份额，而物质浓度效率（SCE）是一种基于统计熵的指标，用于衡量物质在通过系统时的浓缩或稀释程度。$\overline{C}$ 和 $\overline{\mathrm{小号}CË}$）。尽管这两个指标在其一般性说明中都很好地吻合，但是可以观察到在可持续性的不同方面的优先次序方面存在明显的差异。而$\overline{C}$ 专注于增加回收利用，减少排放和缩小系统规模对 $\overline{\mathrm{小号}CË}$。 $\overline{\mathrm{小号}CË}$ 因此，它被认为更适合为奥地利营养管理的可持续发展提供初步的依据。