Short‐range spatial variability of metal contents in soil on a one hectare agricultural plot

As the soil varies spatially, monitoring of temporal changes might be biased by spatial variation. Hence, there is a need to develop tools to identify spatial structures and to optimize sampling designs. This study documents the short‐range variability of lead (Pb), copper (Cu), and chromium (Cr) in a 1‐ha agricultural plot. The aims of this work were to identify the spatial structures of these metals, to discuss their origin, and to optimize sampling design for monitoring the long‐term changes of these characteristics. We used geostatistics and sampling simulations on a set of 65 individual samples. Results demonstrate that small changes in metal contents might be hidden by spatial variation if the sampling design for monitoring is not appropriate and that former land‐use history and old management practices may have long‐term significant effects on the distribution of some metals.