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The conversion of Pampa Biome soils into no-till system for grain production requires acidity correction, at least to fully neutralize exchangeable aluminum (Al). The aim of the study is to...

The use of copper (Cu)-based fungicides to control diseases in vineyards can cause excessive Cu accumulation in soils. Greater Cu availability is expected in acid sandy soils with low organic matter (OM), where the risk of toxicity to plants and environment contamination is high. This study aimed to study the evolution of Cu in acid, sandy soils planted with grapevines for a period of time between 2 and 32 years. Two studies were carried out in South Brazil: in the first study, soil samples, from 19 vineyards were collected and analyzed in the first 0.2 m depth-layer for the total and available Cu. In the second study, 3 soils were selected among the previous 19 according to the age of vineyard (5, 11, and 30 year-old), and their 0.60 m-depth profile was analyzed for 5 fractions of Cu (soluble, exchangeable, mineral, organic, and residual). All the soils were classified as Ultisols. The vineyards with more than 25 years under cultivation had a mean total Cu concentration of 90 mg kg−1 in the 0–0.10 m layer. Approximately 80% of it was potentially available to plants. The greatest total and available Cu were found in the soil surface layers (0.2 m depth), where up to 75% of the total Cu is adsorbed in clay minerals and only 20% is complexed in the OM.

The aim of the present study was to evaluate the effectiveness of P soil addition to mitigate the toxic effect of excess of Cu on grapevine on sandy non-calcareous soil. Micro-propagated plants of 1103 Paulsen rootstock were grown according to a factorial experimental design with two factors: Cu addition (0, 100, 200 and 300 mg kg −1 dw) and P addition (0, 50 and 100 mg kg −1 soil dw). The experiment was conducted in the greenhouse and plants were grown on a sandy soil in rhizoboxes. At the end of the trial, plants were destructively harvested, the biomass and the nutrient concentration of organs were determined. Root growth was evaluated during the trial and the concentration of organic acid in root tissue and exudates was determined. Shoot length and plant biomass declined as Cu concentration in soil increased; the application of P enhanced plant growth and nutritional status. Root biomass decreased at Cu > 100 mg kg −1 and increased in P at 100 mg kg −1 . Phosphorous stimulated root length, diameter and the number of apexes. Root citric acid increased as a response of Cu at 300 mg kg −1 , root ascorbic acid decreased with the increase of Cu (200 and 300 mg kg −1 ) and P at 100 mg kg −1 . The concentration of citric acid from root exudations was higher in Cu at 300 mg kg −1 and Cu at 200 mg kg −1 (compared to control) and P at 100 mg kg −1 soils. The application of P fertilization seems to be a valuable strategy to overcome the toxicity of high concentration of Cu in soil.

The purpose of this study was to evaluate Cu and Zn migration and fractions in sandy soil of vineyards. In Urussanga (SC), Brazil, soil samples were collected from a 4-year-old and 15-yearold vineyard, and from a forested area. In the soils, the chemical characteristics of Cu and Zn were analyzed by the EDTA method, which determines the fraction available in soil; 3050B method of the USEPA for total concentrations, which represents the pseudosoil contents in the soil; and chemical fractionation, which estimates soluble fraction, exchangeable fraction, fraction associated with clay minerals, fraction associated with organic matter and residual fraction. The results show that there is accumulation of Cu and Zn in sandy soils cultivated with grapevines and with frequent fungicide applications. These higher levels were found in soils with longer cultivation time (15 years old), but were restricted to the superficial layers of the soil. Most of the Cu was extracted by EDTA method, and it may be considered as available to plants. The EDTA also extracted a small part of Zn. Most of the Cu in the vineyard soils can be characterized by low geochemical mobility, but in the uppermost soil layers of the oldest vineyard, there was an increase in Cu content associated with soil organic matter. Most of the Zn in the vineyard soil was associated with minerals, which indicates low mobility and also low potential for toxicity to plants and microorganisms. Key words: availability, chemical fractionation, toxicity, environmental contamination, Vitisvinifera. Made available in DSpace on 2019-01-09T23:53:16Z (GMT). No. of bitstreams: 1 Copperandzincaccumulationfractionation.pdf: 618556 bytes, checksum: 35756820009ffff730b38562c1ef7af3 (MD5) Previous issue date: 2019-01-09

Soils used for the cultivation of grapes generally have a long history of copper (Cu) based fungicide applications. As a result, these soils can accumulate Cu at levels that are capable of causing toxicity in plants that co-inhabit the vineyards. The aim of the present study was to evaluate growth parameters and oxidative stress in black oat plants grown in vineyard soils contaminated with high levels of Cu. Soil samples were collected from the Serra Gaúcha and Campanha Gaúcha regions, which are the main wine producing regions in the state of Rio Grande do Sul, in southern Brazil. Experiments were conducted in a greenhouse in 2009, with soils containing Cu concentrations from 2.2 to 328.7 mg kg(-1). Evaluated parameters included plant root and shoot dry matter, Cu concentration in the plant's tissues, and enzymatic and non-enzymatic biochemical parameters related to oxidative stress in the shoots of plants harvested 15 and 40 days after emergence. The Cu absorbed by plants predominantly accumulated in the roots, with little to no translocation to the shoots. Even so, oat plants showed symptoms of toxicity when grown in soils containing high Cu concentrations. The enzymatic and non-enzymatic antioxidant systems of oat plants were unable to reverse the imposed oxidative stress conditions.

Grapevines grown on acid soils with low fertility in southern Brazil are treated with intense foliar applications of copper (Cu) fungicides, resulting in an increased level of Cu in the soil and increased toxicity. The present study evaluated the accumulation and bioavailability of Cu, and soils with varying levels of Cu from the main producing regions of southern Brazil were collected. The forms of Cu present in the soil were assessed using chemical extractants; additionally, oat cultivation was performed, reflecting the use of the plant as an indicator of Cu bioavailability. Cu accumulated in the topsoil, mainly in bioavailable forms, and there was also an increase of Cu up to a depth of 0.4 m. Cu was primarily found in the mineral fraction, with apparent saturation of the soil organic matter functional groups. Inceptisol and Alfisol soils with a long history of cupric fungicide application were found to have levels of Cu toxic to oat plants. Furthermore, accumulated copper in Alfisol soil from the Campanha Gaúcha region of the state of Rio Grande do Sul had higher bioavailability compared to Cu accumulated in Inceptisol soil from the Serra Gaúcha region. In addition, the copper concentration in roots was found to serve as an indicator of Cu bioavailability in soil, but not of copper phytotoxicity in plants.

The purpose of this study was to evaluate the mobility of copper (Cu) and zinc (Zn) in the profile and distribution of sandy soil fractions from vineyards. Soil samples were collected from two vineyards of different ages (14 and 30 years) and a natural field area in the south of Brazil. The chemical characteristics, Cu levels and Zn levels, were analyzed in the soils by extraction with ethylenediamine tetraacetic acid (EDTA) using the 3050B method of USEPA and by chemical fractionation. Cu and Zn were accumulated in the vineyard soils, especially in the uppermost soil layers and in the soil from the oldest vineyard. Approximately, 75% of the total Cu was extracted by EDTA, but only 30% of the total Zn was extracted by EDTA. Most of the Cu, especially in the oldest vineyard, was distributed in the mineral-associated fraction, which is characterized by low geochemical mobility, but another important part of the Cu was distributed in the soil organic matter. Most of the Zn in the soil was distributed in the ...

The ecotoxicological effects of copper (Cu) are of global concern due to the intensive and long-term application of Cu-based fungicides, which may cause Cu to accumulate in the soil. Relative to the effects of other metals, comparatively little is known about the accumulation and translocation of Cu and its effects on other mineral nutrients in plants. This study determined the mineral nutrient distributions under Cu toxicity in potato genotypes differing in their efficiency of use and response to phosphorus (P). Plants were grown in vineyard soils with varied Cu soil levels (2, 5, 36, 67, 96, 270, and 321 mg/kg) during the fall and spring growing seasons. The increase of Cu concentrations in plant tissues was dependent on the external Cu concentrations, and the highest concentrations were observed in root and stolon tissues. The majority of the Cu taken up by the plants accumulated in the tubers. During the fall growing season, plants classified as NER (P-nonefficient and P-responsive) showed the highest sensitivity to excess Cu in terms of growth and nutrition. The plants showing responses to Cu toxicity included plants without expanded leaves and plants without tuber production, whereas genotypes classified as ENR (P-efficient and P-nonresponsive) were able to expand their leaves and produce tubers in all tested soils. Tissue P and Cu concentrations showed a strong correlation with high Cu concentrations in Cambisols, whereas Fe and K tissue concentrations were more strongly correlated with Cu levels in Ultisols. Our data suggest that the middle and apex leaves should be used to assess Cu toxicity in potato plants. This study also provides evidence of noncompetitive uptake of Cu and Fe by potato plants.

Little is known about the impact of N fertilization on fruit production and composition in orange groves grown in soils with low or medium organic matter content in Rio Grande do Sul (RS). This study aimed to evaluate how N fertilization of orange trees cv. 'Lane Late' in a sandy soil may interfere in fruit yield and composition of fruit and juice. The experiment was conducted with orange trees cv. 'Lane Late' growing in Sandy Typic Hapludalf soil, in Rosário do Sul (RS). The plants received applications of 0, 20, 40, 60, 80, 100, 120, 140 and 160kg N ha-1. Total N in leaves, number of fruits per plant, yield, fresh weight, fruit diameter, peel thickness, percentage of fruit juice, peel color, juice color, ascorbic acid content, total soluble solids (TSS) and total titratable acidity were evaluated in 2010/2011 and 2011/2012 crops. In the first crop, especially yield, number of fruits per plant, TSS content in fruit juice and ratio decreased with increasing N rate applied. However, in the second crop, the total titratable acidity of the fruit juice prominently increased with the dose of N applied. In both crops, results were highly influenced by rainfall distribution, which affect the plant physiology, soil N dynamics and, consequently, probability of response to N applied and the loss of mineral N in the soil.

Successive applications of copper-based (Cu) fungicides have increased Cu concentration in vineyard soils, inducing Cu toxicity in young vines and cover crops such as black oat, thus inhibiting growth and development. However, increasing soil phosphorus (P) content can reduce Cu toxicity symptoms. In this context, the aim of this study was to evaluate the effect of Cu toxicity and its alleviation by P fertilization in black oat cultivated in sandy soil. For the experiment, Typic Hapludalf soil samples were air-dried, prepared, and subjected to increasing doses of Cu (0, 30, and 60 mg kg−1) and P (0 and 100 mg kg−1). Subsequently, the soil was incubated and stored in pots, where black oat seedlings were grown for 30 days in a greenhouse. Plant roots subjected to Cu, especially with the highest Cu concentration and without P addition decreased the root cap size, showing early tissue differentiation and lateral root formation near the apical region. Decrease in dry matter (DM) production of roots (50 %) and shoots (67 %) was also observed in the highest Cu concentration. Plants without P addition, regardless of Cu concentration, also had lower root (33 %) and shoot (65 %) DM production. P addition in soil and its increased concentration reduced root anatomical changes and stimulated plant DM production. Therefore, we conclude that excessive Cu concentration alters black oat root anatomical structure, affecting plant growth, especially in sandy soils with low organic matter content. However, P supply can reduce root Cu toxicity symptoms, thus increasing plant dry matter production.

The purpose of this study was to quantify the phosphorus (P) fractions in phosphate-fertilized sandy soils under grapevines. Soil was sampled from a grassland site and two vineyards (13 and 31 years old) in the State Rio Grande do Sul, Brazil, from the layers 0-5, 5-10, 10-15, 15-20, and 20-40 cm deep. The samples were prepared and P fractions were assessed by chemical fractionation. Phosphate fertilization of the vineyard soils increased P contents to a depth of 40 cm, especially in the more recalcitrant fractions but detectable in the more labile fractions as well, which are plant available and may increase the risk of environmental contamination. Phosphate fertilizers and the period of grapevine cultivation had little effect on the levels of organic P forms, whereas cover crops in vineyards could be an appropriate strategy to increase or maintain the levels of soil organic matter and the levels of organic P over the years. Made available in DSpace on 2016-02-23T06:41:17Z (GMT). No. of bitstreams: 1 BRUNETTOCommunicSoilSciPlantAnalysisv44n13p19372013.pdf: 230327 bytes, checksum: 22986a1d27aa4dd93fd00396a838fe73 (MD5) Previous issue date: 2013-08-07

The SPAD reading may be used in estimating total nitrogen content (N) in leaves and even in estimating grape yield in grapevines. The objective of this study was to estimate total N content in leaves and grape yield using the SPAD-502 in grapevines submitted to nitrogen fertilization in soils with clayey and sandy texture. In 2008, two experiments were installed in the Southern region of Brazil. In experiment 1, Cabernet Sauvignon grapevines were planted in a soil with clayey texture and with application of 10, 20, 40 and 80 kg·N·ha-1·year-1. In experiment 2, Cabernet Sauvignon grapevines were planted in a soil with sandy texture and with the application of 0, 10, 15, 20, 40, 80 and 120 kg·N·ha-1·year-1. In the grapevines of the two experiments and during the period from 2008 to 2010, SPAD readings were made on leaves throughout the flowering period and at change in color of the berries using the portable chlorophyll meter Minolta-SPAD-502. The leaves were collected, dried, ground and submitted to analysis of the total N content. In addition, grape yield per hectare was evaluated. The SPAD-502 readings estimated the total N content in flowering and at change in color of the berries in the Cabernet Sauvignon grapevines grown on soils with clayey texture and sandy texture, especially in the first year of evaluation. However, the precision of the SPAD-502 readings is low, with there being no relationship between the SPAD-502 readings and grape yield.

Aims This study investigated Cu uptake and accumulation as well as physiological and biochemical changes in grapevines grown in soils containing excess Cu.