Accurate assessment of the benefits of soil health building practices to soil function and crop performance requires region-specific data and locally relevant indicators. In this study, we used a long-term experiment to measure the effect of 25 yr of differing management on soil health and crop performance indicators in organic and conventionally farmed annual crops in a Mediterranean climate. We measured the strength and consistency of the relationships between several indicators and three functions of a healthy agroecosystem—C storage, net N mineralization, and yields—over two growing seasons and two crop types. Lastly, we used path analysis to test the hypothesis that healthier soils lead to healthier plants and higher yields. Organic plots had greater C stocks and net N mineralization compared with the conventional plots, but lower yields. The path analysis suggested that yields were limited by factors other than N deficiency. The relationships between soil health indicators and soil function were unaffected by crop type but were moderated by yearly changes in weather and operations timing. The indicators most strongly and consistently related to C stocks were permanganate oxidizable C and microbial biomass C, and to N mineralization were CO₂ mineralized from rewet soil and fluorescein diacetate hydrolysis. Our results highlight that (a) different indicators are appropriate for assessing different aspects of soil health, (b) using several years of data in developing robust ranges for indicator interpretation is important, and (c) links between soil and crop health must be assessed mechanistically within a given system.

中文翻译：

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与传统和有机地中海种植系统中土壤健康功能相关的指标

准确评估土壤健康建设实践对土壤功能和作物性能的益处需要特定区域的数据和当地相关指标。在这项研究中，我们使用了一项长期实验来测量 25 年的不同管理对地中海气候下有机和常规种植的一年生作物的土壤健康和作物性能指标的影响。我们在两个生长季节和两种作物类型中测量了几个指标与健康农业生态系统的三个功能（碳储量、净氮矿化和产量）之间关系的强度和一致性。最后，我们使用路径分析来检验更健康的土壤会导致更健康的植物和更高产量的假设。与传统地块相比，有机地块具有更高的碳储量和净氮矿化，但产量较低。通径分析表明，产量受到除氮缺乏以外的其他因素的限制。土壤健康指标和土壤功能之间的关系不受作物类型的影响，但会受到天气和操作时间的年度变化的影响。与 C 库最密切相关的指标是高锰酸盐可氧化 C 和微生物生物量 C，而与 N 矿化相关的指标是 CO₂从再湿土壤和荧光素二乙酸酯水解中矿化。我们的结果强调 (a) 不同的指标适用于评估土壤健康的不同方面，(b) 使用几年的数据来制定指标解释的稳健范围很重要，以及 (c) 必须评估土壤和作物健康之间的联系机械地在给定的系统内。