Influence of pH and industrial activity on total zinc concentrations in agricultural soils, sewage sludges, and beach sands: relationship with plant (Saccharum officinarum) availability.

摘要

A study was conducted to assess the total zinc content in agricultural soils (calcareous Fluvisols), sludges and beach sands from the Mediterranean coastal area of Motril (southeast Spain) and the effect on the bioavailability and total concentrations of zinc in sugarcane grown in these soils. Results showed that zinc levels measured in sewage sludge (145.8±32.2μg/g) and agricultural soils (121.3±40.1μg/g) were statistically higher than those found in beach sands (81.0±22.7μg/g). A regression analysis between the total zinc contents and corresponding pH values in agricultural soils was also performed, establishing that zinc concentrations are inversely related to pH values. Zinc levels measured in agricultural soil samples from industrialized zones were statistically higher than those found in samples from the non-industrialized zone. This indicate the direct influence of industrial activity on zinc concentrations in agricultural soils of the surrounding area. In addition to the total zinc concentrations, pH was also measured in these agricultural soils from the industrial zone. It was found that the ph values of agricultural soils located in the non-industrialized area were significantly higher showing a slow and progressive acidification ofsoils included in the industrialized area. No significant correlation was found between total zinc content in the agricultural soils and metal levels in sugarcane samples. Therefore, zinc uptake by plant was independent of total zinc concentrations on present agricultural soils. No significant correlation was also found between soil pH and zinc concentration in sugarcane despite a negative correlation coefficient obtained between these variables.