Copper
Some studies have reported higher mean Cu values,such as that of Campos (1997) in the fertile Granada Valley, Marín et al. (2000) in vineyard soils of La Rioja and Millán et al. (1983) in the Ebro Valley. The mean value in the study area was close to that of López and
Grau (2004) from agricultural soils in Alicante. The normal Cu content of agricultural soils is 5 to 50 mg kg-1. Concentrations below 8 mg kg-1 could indicate a deficiency for some crops as Cu is an essential micronutrient (McBride, 1994; Kabata-Pendias and Pendias,2001). In this study, all sampled plots were in the normal range and none exceeded the reference value of Pérez
et al. (2002) for agricultural soils in Murcia.