High soil copper may result in adverse effects on natural and agricultural systems. Copper-based pesticides have long been used for control of microbial diseases on fruit tree productive systems. Although copper is relatively safe from a human health management point of view, it can be accumulated in agricultural soils, affecting soil microbiota and litter degradation. The purpose of this review was to collect the available information to critically discuss the role that litter may play in fruit tree productive systems, in terms of copper incorporation into the soil, where this element is used as a pesticide. To achieve this objective, we focused our review on (1) soil contamination by copper-based pesticides in fruit production systems, (2) soil copper behavior, (3) effects of copper contamination on soil organisms, and (4) copper-litter relation in soil. From this review, we can suggest that (1) litter is the main sink of metals coming from atmospheric fallout because it is a good complexing agent of cations, (2) litter decomposition depends on its quality and in soil microbial activity, and (3) soil and litter microbial activity is negatively affected by soil copper enrichment. Thus, under uncontrolled applications of copper-based pesticides in fruit tree productive systems, copper soil enrichment will generate a decrease in microbial activity, diminishing litter breakdown and decreasing dissolved organic carbon formation. This process will also decrease the soluble copper incorporation into the soil; however, this assumption remains unevaluated.
This study assessed both the soil and litter copper (Cu) levels and their relationships with soil microbial activity, in fruit-tree production areas of central Chile where Cu-based pesticides are intensively sprayed. Samples of soil (0–20 cm depth) and litter from a number of selected orchards (kiwi, table grape, plum, and cherry) were collected and analysed for their Cu content and C-induced soil microbial activity. Results showed that the mean total soil Cu level was 225 mg/kg and soluble soil Cu was less than 0.01% of total soil Cu, as expected from pH values of study soils (range of 6.33 to 7.93). However, leaf litter Cu content was 3–7 times higher than in soil (mean of681 mg/kg). Despite the soil and leaf litter Cu concentrations, no effect was observed on the C-induced soil microbial activity. We conclude that leaf litter exerts a protective role, preventing the entry of Cu into the soil and thus soil microbial toxicity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.