Short‐scale distribution of copper fractions in a vineyard acid soil

We studied short‐scale variation in the total concentration of copper and its fractions in a soil vineyard. Soil samples were collected at a depth of 0–20 cm between plant rows (1), between individual plants (2) and at their base (3) in a vine‐grown plot in NW Spain. The mean total content in Cu (Cut) in the soil was found to be 97 mg kg−1 and that of potentially available Cu (CuEDTA) 34 mg kg−1. Copper bound to organic matter (CuOM) and to non‐crystalline inorganic soil components (CuIA) were the dominant fractions and accounted for 34% of total copper each. The contents in exchangeable (Cue), pyrophosphate‐extractable (Cup), oxalic/oxalate‐extractable (Cuo) and total copper (Cut) exhibited statistically significant correlations with pH, sum of base cations (S), cation‐exchange capacity (CEC) and exchangeable calcium (Cae). Both total and fractional copper contents were higher in plant rows than between them, particularly in the centre of the plot. Also, CuOM and CuIA were higher in planting rows than between rows. These copper results may have been influenced by the vine‐growing practices of the area and also by the distribution of plants and their pruning. This variability pattern for Cu distribution is crucial with a view to minimising potential adverse effects of fungicides and optimising any reclamation treatments needed.