title: Effects of zinc addition to a copper-contaminated vineyard soil on sorption of Zn by soil and plant physiological responses.
abstract: The occurrence of high levels of Cu in vineyard soils is often the result of intensive use of fungicides for the preventive control of foliar diseases and can cause toxicity to plants. Nowadays many grape growers in Southern Brazil have replaced Cu-based with Zn-based products. The aim of the study was to evaluate whether the increase in Zn concentration in a soil with high Cu contents can interfere with the dynamics of these elements, and if this increase in Zn may cause toxicity to maize (Zea mays L.). Soil samples were collected in two areas, one in a vineyard with more than 30 years of cultivation and high concentration of Cu and the other on a natural grassland area adjacent to the vineyard. Different doses of Cu and Zn were added to the soil, and the adsorption isotherms were built following the Langmuir's model. In a second experiment, the vineyard soil was spiked with different Zn concentrations (0, 30, 60, 90, 180, and 270mg Zn kg(-1)) in 3kg pots where maize was grown in a greenhouse for 35 days. When Cu and Zn were added together, there was a reduction in the quantities adsorbed, especially for Zn. Zn addition decreased the total plant dry matter and specific leaf mass. Furthermore, with the increase in the activity of catalase, an activation of the antioxidant system was observed. However, the system was not sufficiently effective to reverse the stress levels imposed on soil, especially in plants grown in the highest doses of Zn. At doses higher than 90Znmgkg(-1) in the Cu-contaminated vineyard soil, maize plants were no longer able to activate the protection mechanism and suffered from metal stress, resulting in suppressed dry matter yields due to impaired functioning of the photosynthetic apparatus and changes in the enzymatic activity of plants. Replacement of Cu- by Zn-based fungicides to avoid Cu toxicity has resulted in soil vineyards contaminated with these metals and damaging of plant photosynthetic apparatus and enzyme activity.
authors.affiliation: Departamento de Ciência do Solo da Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. Electronic address: tadeu.t@hotmail.com.
authors.forename: Tadeu L
authors.initials: TL
authors.lastname: Tiecher
authors.affiliation: Departamento de Ciência do Solo da Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Ceretta
authors.affiliation: Departamento de Ciências Agrárias da Universidade Regional Integrada do Alto Uruguai edas Missões, 98400-000 Frederico Westphalen, RS, Brazil.
authors.forename: Tales
authors.initials: T
authors.lastname: Tiecher
authors.affiliation: Departamento de Ciência do Solo da Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Paulo A A
authors.initials: PA
authors.lastname: Ferreira
authors.affiliation: Departamento de Biologia, Centro de Ciências Naturais e Exatas da Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Fernando T
authors.initials: FT
authors.lastname: Nicoloso
authors.affiliation: Departamento de Engenharia Florestal, CESNORS, Universidade Federal de Santa Maria, 98400-000 Frederico Westphalen, RS, Brazil.
authors.forename: Hilda H
authors.initials: HH
authors.lastname: Soriani
authors.affiliation: Departamento de Biologia, Centro de Ciências Naturais e Exatas da Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Liana V
authors.initials: LV
authors.lastname: Rossato
authors.affiliation: Faculty of Science and Technology, Free University of Bolzano, I-39100 Bolzano, Italy.
authors.forename: Tanja
authors.initials: T
authors.lastname: Mimmo
authors.affiliation: Faculty of Science and Technology, Free University of Bolzano, I-39100 Bolzano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Cesco
authors.affiliation: Departamento de Engenharia Rural da Universidade Federal de Santa Catarina, 88034-000 Florianópolis, SC, Brazil.
authors.forename: Cledimar R
authors.initials: CR
authors.lastname: Lourenzi
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia da Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC, Brazil.
authors.forename: Admir J
authors.initials: AJ
authors.lastname: Giachini
authors.affiliation: Departamento de Ciência do Solo da Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Brunetto
mesh_terms: D000327:Adsorption; D001938:Brazil; D003300:Copper / Q000737:chemistry / Q000633:toxicity; D000072480:Farms; D005659:Fungicides, Industrial; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity; D027843:Vitis; D003313:Zea mays / Q000187:drug effects* / Q000254:growth & development; D015032:Zinc / Q000737:chemistry / Q000633:toxicity
chemical_list: D005659:Fungicides, Industrial; D012987:Soil; D012989:Soil Pollutants; D003300:Copper; D015032:Zinc
keywords: Acidic soils; Antioxidant enzymes; Photosynthetic pigments; Potentially toxic elements; Soil solution; Soil sorption capacity