Short-range spatial variability of metal contents in soil on a one hectareagricultural plot

As the soil varies spatially, monitoring of temporal changes might be biase d 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 spati al structures of these metals, to discuss their origin, and to optimize sam pling design for monitoring the long-term changes of these characteristics. We used geostatistics and sampling simulations on a set of 65 individual s amples. Results demonstrate that small changes in metal contents might be h idden by spatial variation if the sampling design for monitoring is not app ropriate and that former land-use history and old management practices may have longterm significant effects on the distribution of some metals.