Liu Yi, Li Yuefen, Harris Paul, Cardenas Laura M, Dunn Robert M, Sint Hadewij, Murray Phil J, Lee Michael R F, Wu Lianhai
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
Sustainable Agriculture Sciences, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, UK.
Geoderma. 2018 Apr 1;315:49-58. doi: 10.1016/j.geoderma.2017.11.029.
In this study, we evaluated the ability of the SPACSYS model to simulate water run-off, soil moisture, NO fluxes and grass growth using data generated from a field of the North Wyke Farm Platform. The field-scale model is adapted via a linked and grid-based approach (grid-to-grid) to account for not only temporal dynamics but also the within-field spatial variation in these key ecosystem indicators. Spatial variability in nutrient and water presence at the field-scale is a key source of uncertainty when quantifying nutrient cycling and water movement in an agricultural system. Results demonstrated that the new spatially distributed version of SPACSYS provided a worthy improvement in accuracy over the standard (single-point) version for biomass productivity. No difference in model prediction performance was observed for water run-off, reflecting the closed-system nature of this variable. Similarly, no difference in model prediction performance was found for NO fluxes, but here the NO predictions were noticeably poor in both cases. Further developmental work, informed by this study's findings, is proposed to improve model predictions for NO. Soil moisture results with the spatially distributed version appeared promising but this promise could not be objectively verified.
在本研究中，我们利用北怀克农场平台一块田地生成的数据，评估了SPACSYS模型模拟径流、土壤湿度、氮通量和草生长的能力。该田间尺度模型通过一种基于链接和网格的方法（网格到网格）进行调整，不仅要考虑时间动态，还要考虑这些关键生态系统指标在田间的空间变化。在量化农业系统中的养分循环和水分运动时，田间尺度上养分和水分存在的空间变异性是不确定性的一个关键来源。结果表明，新的空间分布式版本的SPACSYS在生物量生产力方面比标准（单点）版本在准确性上有了值得肯定的提高。对于径流，未观察到模型预测性能的差异，这反映了该变量的封闭系统性质。同样，对于氮通量，未发现模型预测性能的差异，但在这两种情况下，氮预测都明显较差。根据本研究的结果，建议进一步开展开发工作，以改进对氮的模型预测。空间分布式版本的土壤湿度结果看起来很有前景，但这一前景无法得到客观验证。
