Abstract The precise and accurate assessment of carbon dioxide (CO2) exchange is crucial to identify terrestrial carbon (C) sources and sinks and for evaluating their role within the global C budget. The substantial uncertainty in disentangling the management and soil impact on measured CO2 fluxes are largely ignored especially in cropland. The reasons for this lies in the limitation of the widely used eddy covariance as well as manual and automatic chamber systems, which either account for short-term temporal variability or small-scale spatial heterogeneity, but barely both. To address this issue, we developed a novel robotic chamber system allowing for dozens of spatial measurement repetitions, thus enabling CO2 exchange measurements in a sufficient temporal and high small-scale spatial resolution. The system was tested from 08th July to 09th September 2019 at a heterogeneous field (100 m × 16 m), located within the hummocky ground moraine landscape of northeastern Germany (CarboZALF-D). The field is foreseen for a longer-term block trial manipulation experiment extending over three erosion induced soil types and was covered with spring barley. Measured fluxes of nighttime ecosystem respiration (Reco) and daytime net ecosystem exchange (NEE) showed distinct temporal patterns influenced by crop phenology, weather conditions and management practices. Similarly, we found clear small-scale spatial differences in cumulated (gap-filled) Reco, gross primary productivity (GPP) and NEE fluxes affected by the three distinct soil types. Additionally, spatial patterns induced by former management practices and characterized by differences in soil pH and nutrition status (P and K) were also revealed between plots within each of the three soil types, which allowed compensating for prior to the foreseen block trial manipulation experiment. The results underline the great potential of the novel robotic chamber system, which not only detects short-term temporal CO2 flux dynamics but also reflects the impact of small-scale spatial heterogeneity.

中文翻译：

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一种新型机器人室系统，可以准确准确地确定异质农田的时空 CO2 通量动态

摘要 精确且准确地评估二氧化碳 (CO2) 交换对于识别陆地碳 (C) 源和汇以及评估它们在全球碳预算中的作用至关重要。在解开管理和土壤对测量的 CO2 通量的影响方面存在的巨大不确定性在很大程度上被忽视，尤其是在农田中。其原因在于广泛使用的涡流协方差以及手动和自动室系统的局限性，这些系统要么解释了短期时间变异性，要么解释了小尺度空间异质性，但几乎两者兼而有之。为了解决这个问题，我们开发了一种新型机器人室系统，允许进行数十次空间测量重复，从而能够在足够的时间和高小尺度空间分辨率下进行 CO2 交换测量。该系统于 2019 年 7 月 8 日至 9 月 9 日在位于德国东北部丘陵地面冰碛景观（CarboZALF-D）内的异质场（100 m × 16 m）中进行了测试。预计该田地将进行长期的块状试验操作试验，该试验将扩展到三种侵蚀诱发的土壤类型，并用春大麦覆盖。夜间生态系统呼吸 (Reco) 和白天净生态系统交换 (NEE) 的测量通量显示出受作物物候、天气条件和管理实践影响的不同时间模式。同样，我们发现受三种不同土壤类型影响的累积（间隙填充）Reco、总初级生产力（GPP）和NEE通量存在明显的小尺度空间差异。此外，在三种土壤类型中的每一个的地块之间也揭示了由以前的管理实践引起并以土壤 pH 值和营养状态（P 和 K）的差异为特征的空间模式，这允许在可预见的块试验操作实验之前进行补偿。结果强调了新型机器人室系统的巨大潜力，它不仅可以检测短期 CO2 通量动态，还可以反映小尺度空间异质性的影响。