Identification and phytoremediation potential of spontaneous species in vineyard soils contaminated with copper.

Copper (Cu) contents in vineyard soils due to the application of cupric fungicides cause changes in the native covering flora. Under these conditions, the surviving individuals accumulate the metal in and decrease its availability in the soil, reducing the potential toxicity to grapevine. We have identified spontaneous plant species and their phytoremediation potential from vineyards of Isabella (Vitis labrusca) on two distinct soil types (Inceptisol and Entisol) contaminated with Cu. The results demonstrated that wild species displayed higher Cu contents in the roots than in the shoot, but had low bioaccumulation potential. During summer, the plants were unable to extract and stabilize the metal, although during the winter, Lolium multiflorum, Cyperus compressus and Chrysanthemum leucanthemum demonstrated phytostabilization potential. Among the investigated species, dry matter production and Cu accumulation by Lolium multiflorum indicated that the species is effective to decrease Cu availability in the soil.

High copper content in vineyard soils promotes modifications in photosynthetic parameters and morphological changes in the root system of 'Red Niagara' plantlets.

High copper (Cu) soil contents, due to the continuous vineyard application of Cu fungicides throughout the years, may impair the growth of the shoot and modify the structure of the root system. The current study aimed to investigate the threshold levels of available Cu in the soil causing toxicity effects in young grapevine plants of 'Red Niagara' cultivated in clay soils. Grapevine plantlets were cultivated in pots containing vineyard devoted soils with increasing contents of available Cu (25, 80, 100 and 165 mg kg-1), for 53 days. Photosynthesis and transpiration rates, and the quantum yield of photosystem II (Fv/Fm) were evaluated during the cultivation period. At the end of the experiment, the plant nutrient and leaf chlorophyll were determined, along with the anatomical analysis of the root system structure and plant dry matter determination. Higher levels of available Cu in the soil increased the apoplastic, symplastic and total fraction of the metal in the roots, reducing the other nutrients, especially in the shoots. Photosynthesis, transpiration rates and Fv/Fm were also reduced. Higher levels of Cu led to anatomical changes in the roots, that increased diameter, number of layers in the cortex, vascular cylinder and total root areas. It also resulted in reduced dry matter production by grapevines.

Formas de perdas de cobre e fósforo em água de escoamento superficial e percolação em solo sob aplicações sucessivas de dejeto líquido de suínos / Forms of losses of copper and phosphorus in water of runoff and percolation in soil with successive pig slurry application

As aplicações sucessivas de dejeto líquido de suínos podem aumentar os teores de cobre e fósforo na camada superficial do solo, aumentando as perdas de suas formas por escoamento superficial e percolação. O trabalho teve por objetivo avaliar as perdas e as formas de cobre e de fósforo na solução escoada, na superfície e percolada em solo submetido a aplicações sucessivas de dejeto líquido de suínos, em sistema plantio direto. O experimento utilizado neste estudo foi instalado no ano de 2000, sobre um solo Argissolo Vermelho distrófico arênico. Os tratamentos foram aplicações sucessivas de 0, 40 e 80m³ ha-1 de dejeto líquido de suínos a lanço e na superfície do solo, em sistema plantio direto. Para este trabalho, foram coletadas soluções escoadas e percoladas, durante o ciclo da aveia preta (Avena strigosa), no inverno de 2006, quando o solo apresentava um histórico de 16 aplicações de dejeto. Nas soluções, foi quantificado o sedimento e determinados os teores de Cu, P, cátions e ânions, pH, carbono orgânico dissolvido (COD) e condutividade elétrica (CE). Usando o programa Visual MINTEQ, versão 2.15, se realizou a especiação iônica de Cu e P nas soluções. As maiores perdas de cobre e fósforo do solo ocorrem por escoamento superficial, em áreas submetidas a aplicações sucessivas de dejeto líquido de suínos em sistema plantio direto. O potencial contaminante desses elementos ficou evidenciado pela presença do cobre na forma predominante orgânica (CuCOD) e do fósforo nas formas livres (HPO4(2-) e H2PO4-), na solução escoada.

Successive pig slurry application can increase the copper and phosphorus levels in the soil and the losses of these elements by surface runoff and percolation. The objective of this study is to evaluate the losses and the forms of both copper and phosphorus in the surface runoff and also in/on the percolation solution, on soils with successive pig slurry application under no tillage system. The experiment was installed in 2000, at Typic Hapludalf soil. The treatments consisted of successive applications of 0, 40 and 80m³ ha-1 of pig slurry applied on soil surface in no tillage system. Samples of surface runoff and percolated solutions were collected during the life cycle of oat (Avena strigosa) in the 2006 winter, when the soil had a history of 16 pig slurry applications. The following parameters have been evaluated: Cu, P, cation, anion and pH, dissolved organic carbon and electric conductivity. The Visual MINTEQ program version 2.15 was utilized to estimate the copper and phosphorus ionic speciation. The surface runoff is the most important form of copper and phosphorus loss of the soil. In addition, copper was found in the organic form (CuCOD) and phosphorus in the free forms (HPO4(2-) e H2PO4-) in the surface runoff solution. Thus, these elements could be an important source of water contamination in places where pig farming is widespread.