CopperSome studies have reported hi

CopperSome 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 andGrau (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 Pérezet al. (2002) for agricultural soils in Murcia.Iron and manganese In general, the soil Fe and Mn concentrations are not reported in studies focussing on soil heavy metal content because they are not contaminant elements. Both metals are important in plant nutrition as they areessential crop micronutrients. These elements can be in insoluble forms in calcareous soils causing deficiencies(e.g. ferric chlorosis). The mean Fe value in the study area was lower than the mean obtained by Millán et al. (1983) from agricultural soils of the Ebro Valleyand Campos (1997) in the Granada Valley. In spite of an elevated soil content, total Fe or Mn are not a good indicator of their plant availability. For example, Fe is mainly present in precipitated forms, such as oxides and hydroxides, in these soils. Therefore, Fe deficiencydoes not seem to be due to an insufficient total soil Fe content but to the formation of insoluble compounds. However, further study would be necessary to properly assess deficiency processes of these metals in the study area.

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.Iron and manganese In general, the soil Fe and Mn concentrations are not reported in studies focussing on soil heavy metal content because they are not contaminant elements. Both metals are important in plant nutrition as they are
essential crop micronutrients. These elements can be in insoluble forms in calcareous soils causing deficiencies(e.g. ferric chlorosis). The mean Fe value in the study area was lower than the mean obtained by Millán et al. (1983) from agricultural soils of the Ebro Valley
and Campos (1997) in the Granada Valley. In spite of an elevated soil content, total Fe or Mn are not a good indicator of their plant availability. For example, Fe is mainly present in precipitated forms, such as oxides and hydroxides, in these soils. Therefore, Fe deficiency
does not seem to be due to an insufficient total soil Fe content but to the formation of insoluble compounds. However, further study would be necessary to properly assess deficiency processes of these metals in the study area.

Copper
Some studies have reported higher mean Cu values such as, that of Campos (1997) in the fertile, Granada Valley Mar í n. Et al. (2000) in vineyard soils of La Rioja and Mill and n et al. (1983) in the Ebro Valley. The mean value in the study area. Was close to that of L is PEZ 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 P é rez
et al. (2002) for agricultural soils in Murcia.Iron and manganese, In generalThe soil Fe and Mn concentrations are not reported in studies focussing on soil heavy metal content because they are not. Contaminant elements. Both metals are important in plant nutrition as they are
essential crop micronutrients. These elements. Can be in insoluble forms in calcareous soils causing deficiencies (e.g. Ferric chlorosis).The mean Fe value in the study area was lower than the mean obtained by Mill and n et al. (1983) from agricultural soils of. The Ebro Valley
and Campos (1997) in the Granada Valley. In spite of an elevated soil content total Fe, or Mn are not a. Good indicator of their plant availability. For example Fe is, mainly present in precipitated forms such as, oxides and. Hydroxides in these soils. Therefore,,Fe deficiency
does not seem to be due to an insufficient total soil Fe content but to the formation of insoluble, compounds. However further study, would be necessary to properly assess deficiency processes of these metals in the study area.