Department of Geography, University of Exeter, Exeter, EX4 4RJ, UK.
Rapid Commun Mass Spectrom. 2012 Oct 30;26(20):2413-21. doi: 10.1002/rcm.6336.
The spatial variability of soil properties is poorly understood, despite its importance in designing appropriate experimental sampling strategies. As preparation for a farm-scale agro-ecosystem services monitoring project, the 'North Wyke Farm Platform', there was a need to assess the spatial variability of key soil chemical and physical properties.
The field-scale spatial variability of soil chemical (total N, total C, soil organic matter), soil physical properties (bulk density and particle size distribution) and stable isotope ratios (δ(13) C and δ(15) N values) was studied using geostatistical approaches in an intensively managed grassland.
The scales over which stable isotopes vary (ranges: 212-258 m) were larger than those of the total nutrients, soil organic matter and bulk density (ranges: 84-170 m). Two visually and statistically distinct areas of Great Field (north and south) were identified in terms of co-occurring high/low values of several soil properties.
The resulting patterns of spatial variability suggest lower spatial variability of stable isotopes than that of total nutrients, soil organic matter and bulk density. Future sampling regimes should be conducted in a grid with <85 m distance between sampling locations to sufficiently capture the spatial variability of the measured soil properties on the 'North Wyke Farm Platform'. Consultation of the management histories of the sampled field revealed that it had previously comprised two fields with contrasting management histories, suggesting an effect of management legacy (>5 years) on the patterns of spatial variability.
尽管土壤属性的空间变异性对于设计适当的实验采样策略非常重要，但人们对此知之甚少。作为“North Wyke 农场平台”（一个农场规模的农业生态系统服务监测项目）的准备工作，需要评估关键土壤化学和物理性质的空间变异性。
本研究采用地统计学方法研究了集约化管理草地中土壤化学（总氮、总碳、土壤有机质）、土壤物理性质（体密度和粒径分布）和稳定同位素比值（δ¹³C 和 δ¹⁵N 值）的田间尺度空间变异性。
稳定同位素变化的尺度（范围：212-258 m）大于总养分、土壤有机质和体密度的尺度（范围：84-170 m）。根据几个土壤性质的高/低值共现情况，将大草地（北部和南部）分为两个在视觉上和统计学上明显不同的区域。
空间变异性的结果模式表明，稳定同位素的空间变异性低于总养分、土壤有机质和体密度。未来的采样方案应在距离采样点<85 m 的网格中进行，以充分捕获“North Wyke 农场平台”上测量土壤性质的空间变异性。对采样场地管理历史的咨询表明，该场地以前由两块具有不同管理历史的田地组成，这表明管理历史（>5 年）对空间变异性模式有影响。
