Copper accumulation in vineyard soils: Rhizosphere processes and agronomic practices to limit its toxicity

Abstract

Viticulture represents an important agricultural practice in many countries worldwide. Yet, the continuous use of fungicides has caused copper (Cu) accumulation in soils, which represent a major environmental and toxicological concern. Despite being an important micronutrient, Cu can be a potential toxicant at high concentrations since it may cause morphological, anatomical and physiological changes in plants, decreasing both food productivity and quality. Rhizosphere processes can, however, actively control the uptake and translocation of Cu in plants. In particular, root exudates affecting the chemical, physical and biological characteristics of the rhizosphere, might reduce the availability of Cu in the soil and hence its absorption. In addition, this review will aim at discussing the advantages and disadvantages of agronomic practices, such as liming, the use of pesticides, the application of organic matter, biochar and coal fly ashes, the inoculation with bacteria and/or mycorrhizal fungi and the intercropping, in alleviating Cu toxicity symptoms.

Accumulation and Precipitation of Cu and Zn in a Centenarian Vineyard

“…As applications are made frequently because of the climatic condition of the area, in high amounts and over long term, metal accumulation occurred in the vineyard soils, mainly in aged vines. In the literature, copper accumulation in vineyard soils has often been associated with the Bordeaux mix application (Komárek et al, 2010; Brunetto et al, 2014; 2016), but those studies were made on relatively young vineyards.…”

“…Agricultural inputs are common sources of soil contaminants (Facchinelli et al, 2001; Pietrzak and McPhail, 2004; Ramos, 2006; Vitanović et al, 2010). Especially during grape production, Cu and Zn accumulate in soils in response to phytosanitary treatments and organic fertilization (Chaignon et al, 2009; Brunetto et al, 2016; Tiecher et al, 2017).…”

“…The ion forms that accumulate in soil are also dependent on the contents of organic matter, clays and oxides, as well as soil solution conditions (pH and Eh) and can be estimated using different chemical compounds (Tessier et al, 1979; Husson, 2013). Furthermore, the plant rhizosphere plays a determinant role in the ion forms, affecting ion mobility in the soil (Paradelo et al, 2011; Brunetto et al, 2016) and clay mineral alteration (Hinsinger et al, 2009; Bortoluzzi et al, 2012).…”

“…Many studies have been performed on ion accumulation and its availability in soils and assessment of the role of soil colloid in ion sorption under different chemical conditions (Hogg et al, 1993; Silveira and Alleoni, 2003; Bradl, 2004; Chaignon et al, 2009; Paradelo et al, 2011; Brunetto et al, 2016; Tiecher et al, 2017). Despite these studies, little is known about the mineral changes that occur because of continuous chemical inputs in agricultural lands, especially those of Cu and Zn in vineyards.…”

“…Despite these studies, little is known about the mineral changes that occur because of continuous chemical inputs in agricultural lands, especially those of Cu and Zn in vineyards. Because vineyards present high Cu accumulation in soil, especially in the rhizosphere zone (Brunetto et al, 2016), we hypothesize that this condition remains an important factor that favors geochemical changes, that is, high residual ion forms, and can form Cu‐ or Zn‐bearing minerals in the soil. Thus, if specific soil chemical conditions are satisfied, chemical ion precipitation and mineral crystallization processes can occur (Lindsay, 2001; Baumgartner et al, 2013; Teng, 2013).…”