ABSTRACT A good soil fertility management for soybean production must consider the amount of nutrients that are exported by seeds. In recent decades, soybean yield has increased due to better crop management and genetic improvements, which may affect the amount of nutrients removed. Therefore, this study aimed (i) to analyze the relationship between the concentration of macronutrients in soybean seeds in Brazil with soybean yield and genotypes, and (ii) to update nutrient concentration values in soybean seeds for fertilizer recommendation purposes, comparing them with the values described in the main official fertilization recommendation systems used in Brazil. For this purpose, we used 3,017 observations obtained from 67 studies evaluating at least one macronutrient concentration [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S)] in soybean seeds in the last 45 years in Brazil (from 1974 to 2019). Results indicate that the concentration of macronutrients in soybean seed is affected by both soybean yield and genetic material. Modern genotypes of the Intacta Roundup Ready-2 group remove 15, 21, 18, 17, and 23 % more K, P, Ca, Mg, and S and 4 % less N compared to non-Roundup Ready genotypes. The increase in soybean yield was followed by an increase in the concentration of N and a decrease in the concentration of P and K in soybean seed. Data obtained from studies published between 2015 and 2019 indicates that soybean removes, on average, 57.2, 17.6, 5.5, 2.9, 2.6, and 2.5 kg Mg-1 of N, K, P, S, Ca, and Mg, respectively. These macronutrient concentrations in soybean seeds are in disparity with most reference values described in the official fertilization recommendation systems in Brazil, highlighting an urgent need to review the standard values for replacement fertilization of soybeans. Moreover, future studies should focus on the influence of genetics on soybean seeds composition to ensure high soybean productivity with rational use of fertilizers.

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 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.

RESUMO: O manejo de plantas espontâneas em pomares de macieira (Malus domestica) pode afetar a lixiviação de nitrogênio (N) do solo. O trabalho objetivou avaliar a lixiviação de formas de N em solo sob pomar de macieiras com diferentes manejos de plantas espontâneas. O experimento foi conduzido em um pomar de macieira implantado em 2008. Em outubro de 2011, foram selecionadas 80 plantas e implantados os tratamentos: sem manejo das plantas espontâneas (SM); dessecamento das plantas espontâneas na linha de plantio com uso de herbicidas (DL) e roçada mecânica das plantas espontâneas na linha de plantio (RL). Nas safras 2011/2012, 2012/2013 e 2013/2014 foi avaliada a produtividade. Em maio de 2012 foram instalados lisímetros com cápsula porosa nos tratamentos SM, DL e RL; e na solução coletada a 0,20m em dezesseis épocas foram analisados NH4 +-N e NO3 --N, e calculado o teor de N-mineral. Os maiores teores de NO3 --N e mineral-N ocorreram na solução no solo com DL, o que aumenta a disponibilidade do nutriente às macieiras, mas também potencializa as perdas. O manejo de plantas espontâneas e o fluxo de N na solução não afetaram a produtividade de maçã.

ABSTRACT: Weed management in apple orchards (Malus domestica) can affect the leaching of nitrogen (N) in soil. The study aimed to evaluate the potential leaching of N forms in soil of an apple orchard with different weed management treatments. The experiment was conducted in an apple orchard implanted in 2008. In October 2011, 80 plants were selected and the following treatments were implemented: no weed management (NM), desiccation of weeds on the tree row with herbicide use (DR) and mechanical mowing of weeds on the tree row (MR). Yield was evaluated in the 2011/2012, 2012/2013 and 2013/2014 crop seasons. In May 2012 porous cup lysimeters were installed in the NM, DR and MR treatments. In the solution collected at 0.20m, NH4 +-N and NO3 --N were analyzed sixteen times and mineral N concentration was calculated. The highest concentrations of NO3 --N and mineral N occurred in soil solution with DR, which increases availability of the nutrient to apple trees, but also enhances the potential losses. Weed management and N flow in the solution did not affect apple yield.

RESUMO: Solos cultivados com videiras possuem alto teor de cobre (Cu) disponível, que pode ser tóxico às plantas de cobertura do solo que coabitam vinhedos, como a aveia preta. O estudo objetivou avaliar o efeito da calagem na redução da toxidez por Cu em plantas de aveia preta cultivadas em solo arenoso. Amostras de um Argissolo Vermelho foram coletadas na camada de 0-20cm, secas e submetidas à adição de duas doses de Cu (0 e 50Mg kg-1) e três de calcário (0, 1,5 e 3,0Mg ha-1). O solo foi acondicionado em rhizobox e submetido ao cultivo de aveia preta durante 30 dias. Avaliaram-se a produção de matéria seca das raízes e da parte aérea, o teor de cobre (Cu), cálcio (Ca) e magnésio (Mg) nos tecidos; o teor de Cu no simplasto e apoplasto das raízes, e os teores de Cu, de carbono e valores de pH no solo rizosférico e não rizosférico. A aplicação de calcário reduziu a toxidez por Cu na aveia preta. O Cu foi preferencialmente acumulado nas raízes, especialmente no apoplasto, o que pode ser resultado de mecanismo de tolerância das plantas para evitar o transporte de parte do elemento para a parte aérea.

ABSTRACT: Soils which are cultivated with grapevines have high available copper (Cu) content, which can be toxic to cover crops cohabiting vineyards, such as black oats. This study aimed to assess the effect of liming in reducing Cu toxicity in black oats grown in sandy soils. Samples of a Typic Hapludalf were collected at 0-20cm, dried and subjected to the addition of Cu (0 to 50Mg kg-1) and limestone (0, 1.5, and 3.0Mg ha-1). The soil was placed in a rhizobox and black oats were grown for 30 days. We assessed root and shoot dry matter production, copper (Cu), calcium (Ca) and magnesium (Mg) contents in the tissues; Cu content in the root symplast and apoplast, as well as Cu, carbon and pH values in the rhizosphere and bulk soil. Liming reduced Cu toxicity in black oats. Cu was preferentially accumulated in the roots, mostly in the apoplast, which may be the result of a plant tolerance mechanism to prevent the transport of Cu to the shoots.

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.

RESUMO: O impacto da adubação nitrogenada na produção e composição de frutos em pomares de laranjeiras cultivados em solos com baixo ou médio teor de matéria orgânica do RS é pouco conhecido. Este trabalho objetivou avaliar como a adubação nitrogenada, em solo de textura arenosa, pode interferir na produção, composição de frutos e do suco em laranjeiras cv. 'Lane Late'. O experimento foi conduzido em um pomar de laranjeiras cv. 'Lane Late' instalado sobre um Argissolo Vermelho, em Rosário do Sul (RS). As plantas foram submetidas à aplicação de 0, 20, 40, 60, 80, 100, 120, 140 e 160 kg ha-1 de N. Nas safras de 2010/2011 e 2011/2012 foi avaliado o teor total de N em folhas, o número de frutos por planta, a produção, o peso fresco e diâmetro de frutos, espessura da casca, porcentagem de suco nos frutos, cor da epiderme e do suco, os valores de vitamina C, sólidos solúveis totais (SST) e acidez total titulável. Na primeira safra, especialmente a produção, o número de frutos por planta, o teor de SST no suco e o ratio diminuíram com o aumento da dose de N aplicada. Mas, na segunda safra, de forma destacada, o teor de acidez total titulável no suco aumentou com a dose de N aplicada. Nas duas safras, os resultados foram muito influenciados pela distribuição das precipitações pluviométricas, que afetam a fisiologia da planta, a dinâmica do N no solo e, por consequência, a probabilidade de resposta ao N aplicado, bem como as perdas de N mineral no solo.

ABSTRACT: 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.

RESUMO. O objetivo do trabalho foi avaliar o estado nutricional, produção e composição de pêssegos em pessegueiros submetidos à aplicação de composto orgânico no solo. O experimento foi conduzido, na safra 2008 e 2009, em um pomar da cultivar Chimarrita, enxertada sobre o porta-enxerto Capdeboscq e cultivadas em um solo Cambissolo Húmico, no município de Farroupilha (Estado do Rio Grande do Sul). Os tratamentos foram 0, 9, 18, 36, 72 e 144 litros de composto orgânico por planta-1 ano-1. Avaliou-se o teor de nutrientes totais nas folhas, componentes de produção, produção por planta e hectare e a composição dos frutos em 2008 e 2009, logo depois da colheita e 30 dias após armazenamento. A aplicação de composto orgânico no solo, aumenta os valores de componentes de produção e a produção de pêssego por planta e hectare, nas duas maiores quantidades de composto fornecidas, o que economicamente indica a melhor dose de 72 L de composto por planta-1. A adição de composto orgânico na superfície do solo não afeta o estado nutricional e pouco afeta a composição dos pêssegos após a colheita e depois de 30 dias do armazenamento.

ABSTRACT. The purpose of this study was to evaluate the nutritional state, yield and composition of peaches on peach trees subjected to the application of organic compost to the soil. This experiment was conducted during the 2008 and 2009 cropping season in an orchard containing Chimarrita cultivars grafted onto Capdeboscq rootstocks and Haplumbrept soils in the municipality of Farroupilha (Rio Grande do Sul State), Brazil. The treatments included 0, 9, 18, 36, 72 and 144 liters of organic compost per plant-1 year-1. The total nutrient contents in the leaves, yield components, yields per plant and hectare and compositions of the fruits were evaluated in 2008 and 2009 soon after harvest and after 30 days of storage. The application of organic compost to the soil increased the yield components and the yields per plant and hectare in the two treatments with the highest compost additions, which indicated that the addition of 72 L of compost per plant-1 is ideal economically. The organic compost had little effect on the composition of the peach fruit after harvest and after 30 days of storage.

Abstract High copper (Cu) levels in uprooted old vineyard soils may cause toxicity in transplanted young vines, although such toxicity may be reduced by inoculating plants with arbuscular mycorrhizal fungi (AMF). The objective of this study was to evaluate the effects of AMF on the plant growth, chlorophyll contents, mycorrhizal colonization, and Cu and phosphorus (P) absorption in young vines cultivated in a vineyard soil contaminated by Cu. Commercial vineyard soil with high Cu levels was placed in plastic tubes and transplanted with young vines, which were inoculated with six AMF species (Dentiscutata heterogama, Gigaspora gigantea, Acaulospora morrowiae, A. colombiana, Rhizophagus clarus, R. irregularis) and a control treatment on randomized blocks with 12 replicates. After 130 days, the mycorrhizal colonization, root and shoot dry matter (DM), height increment, P and Cu absorption, and chlorophyll contents were evaluated. The height increment, shoot DM and chlorophyll contents were not promoted by AMF, although the root DM was increased by R. clarus and R. irregularis, which had the greatest mycorrhizal colonization and P uptake. AMF increased Cu absorption but decreased its transport to shoots. Thus, AMF species, particularly R. clarus and R. irregularis, contribute to the establishment of young vines exposed to high Cu levels.

O trabalho objetivou avaliar a resposta à adubação com fósforo (P) e potássio (K) e estabelecer o nível crítico no solo e no tecido de P e K em pereira. Dois experimentos foram conduzidos em São Joaquim (SC). No experimento 1 as plantas receberam anualmente a aplicação de doses crescentes de fertilizante fosfatado (0; 40; 80; 120 e 160 kg de PO5 h2a-1), enquanto no experimento 2 foram aplicadas anualmente doses crescentes de fertilizante potássico (0; 40; 80; 120 e 160 kg de K2O ha-1). Nos dois experimentos foi coletado anualmente solo nas camadas de 0-10; 10-20 e 0-20 cm, onde foi analisado o teor de P disponível (experimento 1) e K trocável (experimento 2). Anualmente foram coletadas folhas completas que foram submetidas à análise do teor total de P (experimento 1) e K (experimento 2). Avaliaram-se o número e a massa dos frutos por planta e a produção de frutos. A aplicação de P no solo cultivado com pereira incrementou o teor do nutriente no solo e, na maioria das safras, na folha completa. Porém, o incremento do teor de P disponível no solo e na folha não foi acompanhado de aumentos nos componentes de produção e na produção de frutos, impossibilitando o estabelecimento do nível crítico de P no solo e no tecido. A aplicação de K no solo aumentou o teor do nutriente no solo e, na maioria das safras, na folha completa da pereira, mas o teor de K na folha completa diminuiu na safra com maior produção de frutos. O incremento de K trocável no solo e na folha não foi acompanhado de aumentos nos componentes de produção e na produção de frutos, não permitindo o estabelecimento do nível crítico de K no solo e no tecido.

The aim of this study was to evaluate the response to phosphorus (P) and potassium (K) fertilization and to establish the critical levels of P and K in the soil and in the plant tissue in pear trees. Two experiments were conducted in São Joaquim (SC), Brazil. In experiment 1, the plants received annually the application of increasing rates of phosphate fertilizer (0, 40, 80, 120 and 160 kg P2O5 ha-1), while in experiment 2, increasing rates of potassium fertilizer (0, 40, 80, 120 and 160 kg K2O ha-1) were applied annually. In the two experiments, soil was collected annually from the 0-10, 10-20 and 0-20 cm layers, and the available P (experiment 1) and exchangeable K (experiment 2) content was analyzed. Whole leaves were collected annually, which were subjected to analysis of total P (experiment 1) and total K (experiment 2) content. The number and weight of the fruits per plant and fruit yield were evaluated. Application of P on the soil planted with pear trees increased the nutrient content in the soil and, in most crop seasons, in the whole leaf, but it did not affect the yield components and fruit yield. The application of K on the soil with pear trees increased the nutrient content in the soil and, in most of the crop seasons, in the whole leaf, but the potassium content in the whole leaf decreased in the crop season with greater fruit yield. The yield components and fruit yield were not affected by K fertilization.

A aplicação de composto orgânico no solo pode incrementar a produção de pêssego, porém parte do N pode ser perdido por lixiviação e volatilização. O trabalho objetivou avaliar o estado nutricional das plantas, a produção de pêssego, a lixiviação de formas de N no solo e a volatilização de N-NH3 em um pomar de pessegueiro com a adição de composto orgânico produzido a partir de resíduos de agroindústrias de suco, resíduos de abatedouro de aves e serragem. O pomar foi implantado em 2009 e, em julho de 2010, 2011 e 2012, foram aplicados 0, 3, 6, 12 e 24L de composto por m2 e avaliaram-se os teores totais de nutrientes nas folhas e a produção. Em 2012, usando lisímetros instalados a 20 e a 40cm de profundidade, avaliaram-se as formas de N lixiviadas na solução percolada nos tratamentos 0 e 24L de composto. Usando câmeras coletoras, foi avaliada a volatilização de N-NH3 em todos os tratamentos até 478h depois da deposição do composto no solo. A aplicação de composto na superfície do solo incrementou o teor de K e N nas folhas completas, aumentando a produção de frutos. A aplicação de composto no florescimento aumentou a concentração de nitrato na solução do solo, somente na profundidade de 20cm. A emissão de amônia aumentou com o incremento da dose de composto aplicado, especialmente e nos períodos de maior temperatura

The application of organic compost to the soil can increase the production of peach, although part of the N may be lost by leaching and volatilization. The aim of this study was to evaluate the nutritional status, yield of peaches, leaching of N forms and volatilization of NH3-N in a peach orchard with the addition of compost produced from agroindustrial juice waste, poultry slaughterhouse residues and sawdust. The orchard was established in 2009, and in july 2010, 2011 and 2012 the quantities of 0, 3, 6, 12 and 24L of organic compost per m2 were applied on a peach orchard and the total nutrient content in leaves and production was evaluated. In 2012, using lysimeters installed at 20 and 40cm deep in the soil, it was measured the forms of N in the solution in the treatments of 0 and 24L of compost. The volatilization of NH3-N was assessed in all the treatments up to 478h after compost application on the soil. The application of compost on the soil surface increased the content of K and N in whole leaves, increasing fruit production. The compost application at flowering increased the concentration of nitrate in the soil solution at a depth of only 20cm. The ammonia emission increased especially with the augmenting dose of compost applied, and in periods of higher temperature

A aplicação de fontes de nitrogênio (N) em pomar de macieira pode incrementar o teor do nutriente no solo ao longo do ciclo, afetar o estado nutricional e a produção, mas parte do N pode ser perdido por lixiviação. O trabalho objetivou avaliar o teor de N total em folhas, a produção e o fluxo de N no solo e na solução, em um pomar de macieira com a aplicação de distintas fontes de N, em um experimento em Urubici (SC). Plantas foram selecionadas, receberam a aplicação de ureia (U), ureia peletizada (UP) e cama sobreposta de suínos (CS); além de um tratamento sem adubação (SA). Nas safras 2011/2012 e 2012/2013 foram analisados teores de N em folhas completas e mensurados o crescimento das plantas e a produção de frutos. Foram coletadas amostras de solo e de solução, e analisados os teores de N-NH4 + e N-NO3 - ao longo da segunda safra. Aplicações de U, UP e CS aumentaram o rendimento da macieira no segundo ano, mas o teor de N em folhas não foi afetado nas duas safras. A aplicação de N afetou o fluxo de formas do nutriente no solo e na solução ao longo do ciclo da cultura, com pequenos incrementos nos teores do solo e da solução em períodos próximos à aplicação das diferentes fontes de N

The application of nitrogen (N), from different sources, in apple orchard can increase soil N content, affecting the plant's nutritional status and yield, but part of the N can be lost by leaching. With the aim of assessing plant nutritional status and yield, and N flow in the soil and solution an experiment was carried out in in an apple orchard in Southern Brazil, applying different N source. Selected plants received the following treatments: application of urea, pelletized urea or pig deep litter, besides a control without fertilization. In the 2011/2012 and 2012/2013 crop seasons, N contents in whole leaves were analyzed and plant growth and fruit yield parameters were measured. Soil and soil solution samples were collected and the NH4 +-N and NO3 --N contents were analyzed during the second crop season. Application of pig deep litter, urea and pelletized urea increased apple yield in the second crop season, with no differences among treatments in leaf total N content at any time period. The application of N to the soil affected the flow of nutrient forms in the soil and in the solution throughout the apple crop cycle, with small increases in soil and in solution contents in periods near the application of the different N sources to the 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.