ABSTRACT The objective of this work was to assess the effects of A. brasilense inoculation on seeds on the yield performance of maize and black oat as a function of nitrogen rate over a 3-year succession. The experiment was conducted from 2015 to 2018 under field conditions. Maize was grown for three growing seasons in rotation with two seasons of black oat at the same experimental site. A randomized block design with a split-plot arrangement was used. Main plots consisted of A. brasilense inoculation (inoculated and uninoculated plants) and subplots of four nitrogen rates (0, 40, 80, and 120 kg ha−1). Maize plants were evaluated for biometric parameters, yield, and yield components at flowering. Black oat plants were analyzed for dry matter yield at flowering. The inoculation of A. brasilense in maize and black oat seeds in succession does not promote productivity nor does it favor the nitrogen fertilization of these cultures.

ABSTRACT The objective was to evaluate the effect of winter cover crops on the agronomic performance of maize during five crop seasons in a clayey Inceptisol with reduced mineral nitrogen (N) inputs. The treatments were seven single cover crops: white oats (Avena sativa L.), black oats (Avena strigose Schreb.), ryegrass (Lolium multiflorum L.), canola (Brassica napus L.), vetch (Vicia sativa L.), fodder radish (Raphanus sativus L. and red clover (Trifolium pratense L.); a mix (black oats + vetch and a fallow. During summer, in succession to the cover crops, maize was grown under no-tillage. The attributes were evaluated in two stages of maize development: flowering (morphological components and physiological maturation (yield components). Differences in morphologica and yield variables were observed in all crop seasons, with emphasis on grain yield, number of grains per row (NGR and ear length (EL). The use of vetch showed greater contribution to the development of maize in relation to the other cover crops used, promoting an increase in stem diameter (SD), E and NGR in all crop season and directly reflecting in higher grain yield. On the other hand, when maize was grown under cover crops commonly used in southern Brazil, such as ryegras and white oats, the yield was similar to fallow. The results showed that vetch promoted higher maize yields, probably by N mineralization and reinforce the hypothesis that cover crops in the off-season can aggregate benefits to crops in succession, especially in terms of nutrition.

ABSTRACT: This study evaluated P pools after nine years of successive application of either pig slurry (PS) or deep pig litter (DL) in a no-till Ultisol from southern Brazil. The experiment was established in Dec 2002 with the treatments control, application of 90 and 180 kg N ha−1 N as PS and as DL. In Mar 2010, soil samples were taken at six layers up to 30 cm deep. Total organic and inorganic P were assessed by the ignition method, and P compounds classes were evaluated by 31P-NMR spectroscopy. Total soil P increased proportionally with the P amount applied via DL and PS. Only DL application increased soil organic P, mainly at the highest dose and in the uppermost soil layers. The application of high doses of manure to these soils under no-till to meet crop N demands significantly increased P accumulation at the soil surface, especially with DL. This, in turn, increases the risk of contamination of water bodies due to P transfer from soil to rivers via runoff. The ignition method overestimates organic P compared to P-NMR. The highest proportion of organic P estimated by the ignition and P-NMR methods, at surface layers in the control suggests that inorganic P is added to the plots treated, increasing inorganic P and decreasing organic P. Moreover, with no P additions to the control, inorganic soil P is removed by plants, causing an apparent increase in the organic P proportion.

Resumo: O objetivo deste trabalho foi avaliar a produtividade e a composição do mosto de videiras 'Cabernet Sauvignon' e 'Chardonnay' submetidas a aplicações de fósforo em solo de região de altitude no Sul do Brasil, durante três safras. Os experimentos 1 e 2 foram realizados em vinhedos comerciais de 'Cabernet Sauvignon' e de 'Chardonnay', respectivamente, no município de Água Doce, na região Meio-Oeste do estado de Santa Catarina. O solo dos dois vinhedos foi classificado como Cambissolo Húmico. A fonte de P utilizada foi o superfosfato triplo (45% de P2O5). De 2011 a 2013, no florescimento, foram aplicados 0, 10, 20, 40 e 80 kg ha-1 de P2O5 na projeção da copa, na superfície do solo, sem incorporação, em ambos os vinhedos. Avaliaram-se concentração de P no solo e na folha, variáveis de produção e qualidade do mosto. O incremento na disponibilidade de P diminuiu os valores de acidez total titulável e de ácido tartárico no mosto da videira 'Cabernet Sauvignon' na safra de 2013/2014 e aumentou os valores de pH e sólidos solúveis totais no mosto da videira 'Chardonnay' na safra de 2011/2012. A aplicação de fósforo no solo aumenta os níveis de fósforo disponível, mas não resulta em maiores produtividades das videiras 'Cabernet Sauvignon' e 'Chardonnay'.

Abstract: The objective of this work was to evaluate the yield and must composition of 'Cabernet Sauvignon' and 'Chardonnay' grapevines subjected to phosphorus applications to a soil from a high-altitude region of Southern Brazil, during three crop seasons. Experiments 1 and 2 were carried out in 'Cabernet Sauvignon' and 'Chardonnay' commercial vineyards, respectively, in the municipality of Água Doce, located in the Midwestern region of the state of Santa Catarina. The soil from the two vineyards was classified as a Typic Humicryept. The used source of P was triple superphosphate (45% P2O5). From 2011 to 2013, at flowering, a total of 0, 10, 20, 40, and 80 kg ha-1 P2O5 were applied in the crown projection area, to the soil surface, without incorporation, in both vineyards. Soil and leaf P concentration, yield parameters, and must quality were evaluated. The increase in P availability decreased total titratable acidity and tartaric acid in the must of the 'Cabernet Sauvignon' grapevine in the 2013/2014 crop season and increased pH and total soluble solids in the must of the 'Chardonnay' grapevine in the 2011/2012 crop season. Phosphorus application to the soil increases the levels of available phosphorus, but does not result in higher yields for 'Cabernet Sauvignon' and 'Chardonnay' grapevines.

ABSTRACT The overloading of soil with manure or mineral fertilizers enhances phosphorus (P) availability, promoting its loss to water bodies and increasing the risk of eutrophication. In this sense, the establishment of an environmental P threshold is a simple and useful tool to classify soils regards its risk of P losses. Here we propose a P-threshold for soils from the state of Rio Grande do Sul (RS) in Brazil, with the soil clay content as the principal variable of the model. Samples from 20 representative soils of Rio Grande do Sul State were collected in the 0.00-0.10 and 0.10-0.20 m layers. Samples were physically and chemically characterized and incubated with P rates varying from 0 to 100 % of its maximum adsorption capacity. After 20 days of incubation, the P availability was determined in water and Mehlich-1 extractant. We assessed trough segmented linear functions the value of P-Mehlich in which the levels of P water enhance abruptly (i.e., breaking point) to determine the P limit for each soil. Subsequently, the P limit values were linked to the clay content in the sample, adopting the linear equation arising from it as the P-threshold. Adding a safety margin of 20 % to the P-threshold equation, we propose a simplified one “P-threshold = 20 + clay”. Based on the current critical level of P adopted by the regional recommendation in RG, the equation proposed does not limit the production of the most crop species.

Resumo: O objetivo deste trabalho foi avaliar as modificações de frações de fósforo em um Cambissolo Húmico cultivado com vinhedos, após 62 anos de fertilização adicional com cama-de-aves. Amostras de solo foram coletadas de dois vinhedos (V1 e V2) e de uma área de floresta (F) adjacente a eles. Foram aplicados 1.362 e 910 kg ha-1 de P ao V1 e ao V2, respectivamente, durante os últimos 62 anos de cultivo. Amostras de solo foram coletadas a 0-10, 10-20, 20-30 e 30-40 cm de profundidade, para análises das propriedades físico-químicas do solo. A adição de cama-de-aves ao solo dos vinhedos aumentou os teores de P inorgânico (Pi) em todas as frações, exceto na fração residual, principalmente à profundidade de 0-10 cm, em comparação à área de floresta. A adição de cama-de-aves como fertilizante não afeta os estoques de P orgânico (Po) do Cambissolo Húmico, apenas aumenta os teores de Pi do solo.

Abstract: The objective of this work was to evaluate changes in phosphorus fractions in a Humic Cambisol cultivated with vineyards, after 62 years of additional fertilization with poultry litter. Soil samples were collected from two vineyards (V1 and V2) and a forested area adjacent to them. A total of 1,365 and 910 kg ha-1 P were applied to V1 and V2, respectively, throughout the past 62 years. Samples were collected at 0-10, 10-20, 20-30, and 30-40-cm soil depths for the analysis of soil physicochemical properties. The addition of poultry litter to the soil of the vineyards increased the contents of inorganic P (Pi) in all fractions, except in the residual fraction (residual-P), mainly at the 0-10-cm soil depth, in comparison with the forested area. The addition of poultry litter as fertilizer does not affect the organic P (Po) stock in the Humic Cambisol, it only increases the Pi contents of the soil.

ABSTRACT The present study aimed to evaluate the accumulation and distribution of Cu and Zn fractions in the profile of an Inceptisol by application of fungicides with a previous history of apple cultivation in southern Brazil. Stratified soil samples (0.0 – 0.025 m, 0.025 –0.050 m, 0.05 – 0.10 m, 0.10 – 0.15 m, 0.15 – 0.20 m and 0.20 – 0.40 m depth) were collected in two apple orchards (8 years old and 18 years old), and in a native pasture area adjacent to the orchards. The soil was subjected to analysis of physical and chemical properties and to chemical fractionation of Cu and Zn. The fractions of soluble, exchangeable, organic, residual and total Cu and Zn accumulated in the topsoil (0.0 – 0.025 m) of the orchards, being higher in the orchard cultivated for 18 years. Most Cu, especially in the topsoil of the 18 years old orchard, accumulated in the less stable organic fraction, which can potentiate toxicity to plants and transfer Cu e Zn to ground water. In deeper layers, Cu was also distributed in the residual and mineral fractions, which are more stable. Most Zn in the soil of the apple orchards was distributed in the mineral and residual fractions, which have low mobility and low potential toxicity to plants.

ABSTRACT 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 pseudo-soil 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.

ABSTRACT Phosphorus (P) applications at dosages higher than the necessary may cause P buildup in the soil labile fractions and, consequently, pollution of water sources. This study aimed to assess accumulation of P fractions as well as the parameters of adsorption isotherms in soil profiles having a history of application of phosphate fertilizers and cultivated with apple trees. Soil samples were collected from an area with no history of cultivation and 2 apple orchards cultivated for 8 (P8) and 18 (P18) years, in the city of Urubici, Santa Catarina, southern Brazil. Soil samples were air dried, sieved in a 2-mm mesh, and subjected to chemical analyses (P adsorption) besides P chemical fractionation. Applications of phosphate fertilizers to the orchards, particularly P18, increased the inorganic and organic concentrations of P in all fractions. The distribution of P in organic and inorganic forms in the planted soils was similar to the distribution observed for the native vegetation soil. The highest inorganic labile P fraction, the lowest maximum P adsorption capacity, and the highest equilibrium concentration values at P18 are indicators of a higher environmental pollution risk of the orchards soils compared to the native soil.

As aplicações de fertilizantes fosfatados na adubação de pré-plantio e de manutenção, sem considerar critérios técnicos, podem causar o acúmulo e a alteração das frações de P em solos cultivados com videira. Este trabalho objetivou quantificar o acúmulo de frações de P em solos com textura arenosa, cultivados com videira e com histórico de aplicações excessivas de fertilizantes fosfatados. Em dezembro de 2010, foram selecionados dois vinhedos, um com quatro e outro com 15 anos de idade, localizados no município de Urussanga, Santa Catarina, Brasil. Foram abertas três trincheiras em cada área e, em seguida, foi coletado solo nas camadas de 0-5, 5-10 e 10-20 cm. O solo foi seco, passado em peneira e submetido a análises de atributos químicos, fracionamento químico de P e isotermas de adsorção. As aplicações excessivas de fertilizantes fosfatados na adubação de pré-plantio e de manutenção em vinhedos, em solos de textura arenosa, aumentaram o teor de P até 20 cm de profundidade, especialmente nas frações lábeis extraídas pela resina trocadora de ânions e NaHCO3 e na fração não lábil extraída por HCl 1,0 mol L-1. A aplicação de fertilizantes fosfatados e o tempo de cultivo da videira influenciaram os teores de P em formas orgânicas na fração lábil extraída por NaHCO3 0,5 mol L-1 e, principalmente, na fração moderadamente lábil extraída pelos extratores NaOH 0,1 mol L-1 e 0,5 mol L-1. As adubações fosfatadas nos vinhedos com longo período de cultivo, 15 anos, aumentaram a quantidade de P dessorvido em água, indicando risco de contaminação ambiental das águas superficiais e subterrâneas. A adição de fertilizantes fosfatados na adubação de pré-plantio, sem considerar os resultados da análise de solo, da adubação de manutenção, do tecido vegetal e da expectativa de produção, resultou nos valores mais baixos de capacidade máxima de adsorção P na camada de 0-5 cm do vinhedo 2, com longo período de cultivo, indicando a saturação de parte dos sítios de adsorção.

In vineyards, if phosphate is applied both before planting and at intervals during growth without consideration of technical criteria, the soil P fractions may be increased and their proportions altered. This study was carried out to evaluate the accumulation of P fractions and the parameters of the adsorption isotherm in a sandy Typic Hapludalf soil in vineyards with a history of successive and excessive phosphate fertilization. In December 2010, two vineyards were selected, one 4 and the other 15 years old, in Urussanga, State of Santa Catarina (Brazil). Three trenches were dug in each area and soil was collected from the 0-5, 5-10 and 10-20 cm depth ranges. The soil samples were dried in a forced-air oven, sieved and subjected to chemical analyses, P chemical fractionation and P adsorption isotherms. Excessive phosphate fertilization, before and during cultivation, particularly in the older vineyard and, consequently, with a longer history of phosphate fertilization, increased the inorganic P concentrations to the depth of 20 cm, especially in labile fractions extracted by anion exchange resin and NaHCO3 in the non-labile fraction, as well as in the non-labile fraction extracted by 1.0 mol L-1 HCl. The application of phosphate fertilizers and the long cultivation period increased the P levels in the organic labile fraction extracted by 0.5 mol L-1 NaHCO3, and especially in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH. Phosphate fertilization of older vineyards, i.e., cultivated for 15 years, increased the amounts of P desorbed in water, indicating a risk of contamination of surface waters and groundwater. The phosphate fertilization before planting, without considering the results of soil analysis, and during cultivation, disregarding the results of soil analysis, leaf analysis and expected yield, led to a reduction in the maximum P adsorption capacity in the 0-5 cm layer of vineyard 2, indicating saturation of part of the reactive particle adsorption sites.

As aplicações de fósforo (P) em vinhedos podem causar o acúmulo desse nutriente no solo e maximizar seu potencial poluente. Este trabalho objetivou quantificar as frações de acumulação de P em solos arenosos cultivados com videiras na região Sul do Brasil. Para isso, amostras de solo foram coletadas nas camadas de 0-5, 6-10 e 11-20 cm em uma área de campo nativo e em dois vinhedos: um com 14 anos de cultivo (vinhedo 1) e outro com 30 anos (vinhedo 2), localizados no município de Santana do Livramento, Rio Grande do Sul (RS), Brasil. As amostras foram secas, moídas e submetidas ao fracionamento químico de P. Os resultados evidenciaram que os teores de P inorgânico aumentaram até 20 cm de profundidade, principalmente no vinhedo 2, em especial nas frações lábeis extraídas por resina de troca aniônica e por NaHCO3, na fração moderadamente lábil, extraída por NaOH 0,1 e 0,5 mol L-1, e na fração não lábil, extraída por HCl 1 mol L-1, representando potencial de eutroficação das águas. As aplicações de fertilizantes fosfatados na adubação de correção e de manutenção nos vinhedos com maior tempo de cultivo aumentaram os teores de P na fração orgânica extraída por NaHCO3 na camada de 0-5 cm, e na fração moderadamente lábil extraída por NaOH 0,1 mol L-1, até 20 cm de profundidade.

Phosphorus (P) applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm) were collected from a native grassland area and two vineyards, after 14 years (vineyard 1) and 30 years (vineyard 2) of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO3, in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH, and in the non-labile fraction extracted by 1 mol L-1 HCl, indicating the possibility of water eutrophication. Phosphorus application and grapevine cultivation time increased the P content in the organic fraction extracted by NaHCO3 from the 0-5 cm layer, and especially in the moderately labile fraction extracted by 0.1 mol L-1 NaOH, down to a depth of 20 cm.

As aplicações sucessivas de dejetos de suínos, na forma líquida, podem incrementar os teores de carbono orgânico total no solo e de nutrientes, bem como alterar os atributos relacionados à acidez do solo, porém há pouca informação acerca do efeito do uso de cama sobreposta de suínos sobre os atributos da acidez do solo e o carbono orgânico. Este trabalho objetivou avaliar a alteração nos teores de carbono orgânico e nos atributos relacionados à acidez em um solo com histórico de aplicação de dejetos líquidos de suínos e cama sobreposta. Após oito anos da instalação de um experimento localizado no município de Braço do Norte, Santa Catarina (SC), sobre um Argissolo Vermelho, foram coletadas amostras de solo nas camadas de 0-2,5, 2,5-5, 5-10, 10-15, 15-20 e 20-30 cm, em tratamentos sem aplicação de dejeto e com a aplicação de dejetos líquidos de suínos e de cama sobreposta de suínos em duas doses: para suprir uma e duas vezes a necessidade de N para a sucessão milho e aveia-preta. O solo foi seco, moído, passado em peneira e submetido à análise de carbono orgânico total, pH em água, Al, Ca e Mg trocáveis; com base nos dados obtidos, calcularam-se a capacidade de troca de cátions efetiva (CTCefetiva) e a pH 7.0 (CTCpH7,0), H+Al e a saturação por bases e Al. Os resultados mostram que as aplicações de dejetos líquidos de suínos e cama sobreposta durante oito anos aumentaram o teor de COT e a CTC no solo até a profundidade de 30 cm. A aplicação de cama sobreposta de suínos diminuiu os valores de acidez ativa e de saturação por Al e aumentou os valores de saturação por bases até 30 cm de profundidade. O uso de dejetos líquidos por oito anos não provocou nem acidificação nem correção da acidez do solo, indicando que o efeito desse resíduo nos atributos da acidez do solo foi pequeno ou nulo.

Successive applications of liquid swine waste to the soil can increase the contents of total organic carbon and nutrients and change acidity-related soil chemical properties. However, little information is available on the effects of swine waste application in solid form, as of swine deep-litter. The objective of this study was to evaluate alterations of organic carbon and acidity-related properties of a soil after eight years of pig slurry and deep-litter application. In the eighth year of a field experiment established in Braço do Norte, Santa Catarina (SC) on a sandy Typic Hapludalf samples were taken (layers 0-2.5; 2.5-5; 5-10; 10-15; 15-20 and 20-30 cm) from unfertilized plots and plots with pig slurry or deep-litter applications, providing the simple or double rate of N requirement of Zea mays and Avena strigosa in rotation. Soil total organic carbon, water pH, exchangeable Al, Ca and Mg, and cation exchange capacity (CECeffective and CECpH7.0), H+Al, base saturation, and aluminum saturation were measured. The application of pig slurry and deep-litter for eight years increased total organic carbon and CEC in all soil layers. The pig slurry and deep-litter applications reduced active acidity and aluminum saturation and increased base saturation down to a depth of 30 cm. Eight years of pig slurry application did not affect soil acidity.