ABSTRACT The aim of this study was to evaluate the effect of new Ca sources sprayed on ‘Fuji Suprema’ and ‘Maxi Gala’ apple trees on nutrient levels in leaves and fruit, as well as on fruit ripening features and quality at harvest time and after cold storage. Experiments were carried out in a commercial orchard planted with ‘Fuji Suprema’ and ‘Maxi Gala’ apple trees in Caçador, Santa Catarina state, Brazil. Application of different Ca sources and untreated trees were evaluated in each experiment. Fruit were harvested at two different ripening stages and analyzed based on the following variables: fruit ripening at harvest time, as well as fruit quality and incidence of physiological disorders after 210-day storage at 1 °C. Calcium applications did not change Ca levels in the leaves and of the whole fruit. Calcium levels in fruit peel increased in cultivars Maxi Gala and Fuji Suprema due to leaf Ca applications. ‘Maxi Gala’ apples recorded higher postharvest incidence of physiological disorders, such as greater loss of fruit firmness than ‘Fuji Suprema’ apples (Due to 1-methylcyclopropene [1-MCP] application on ‘Fuji Suprema’ apples). Calcium applications did not change fruit maturation (starch index and pulp firmness) or apple pulp firmness preservation in both cultivars, although they reduced the incidence of bitter pit disorder in ‘Maxi Gala’ apples. The new sources of Ca tested did not increase Ca contents, nor did they reduced the risk for physiological disorder compared to the standard CaCl2 treatment that has been commercially used for decades as the main Ca fertilizer.

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.

The presence of cover crops in vineyards may decrease the availability of nitrogen (N) derived from fertilizer to grapevines. The present study aimed to evaluate the recovery of urea-15N and growth of young grapevines with and without natural vegetation in plant rows. The study was conducted in southern Brazil on one-year-old Chardonnay grapevines grown in soils with and without cover crops. The grapevines were subjected to the application of 40 kg N ha-1 in the form of urea-15N at 3% 15N atom excess. Dry matter yield, total N and fertilizer N were assessed in grapevines and soil layers. A small amount of N that is applied during the growing season of the grapevines is readily assimilated by the plants. The maintenance of cover crops in young vineyards may favor the maintenance of higher levels of N in the subsurface layers of the soil, contributing to the nutrition of the grapevines in the following growth cycles. The presence of cover crops reduced the importance of nitrogen fertilization in the growth cycle of grapevines because a large part of N absorbed by grapevines was derived from other sources. Nitrogen derived from the fertilizer applied to the soil in the presence or absence of cover crops was mainly concentrated in the newly-formed vegetative grapevine organs (leaves and shoots).

ABSTRACT In Southern Brazil, agricultural soils are often treated over long periods with annual pig slurry (PS) applications, and their influence on soil nutrient dynamics should be monitored. This study aimed to evaluate the P forms accumulated in the soil and some biological and biochemical parameters of the P cycle after 19 successive PS applications over eight years, in a no-tillage (NT) system. Pig slurry was applied at rates of 0, 20, 40, and 80 m3 ha-1 per crop. Several P forms (available P, microbial P, phosphatase enzyme, total organic and inorganic P) in the 0.00-0.05 and 0.05-0.10 m soil layers were analyzed. Increases up to 5,523 % in available P, 308 % in microbial P, 104 % in phosphatase enzyme activity, 91 % in organic P, 251 % in inorganic P, and 19 % in Total-P were observed in the 0.00-0.05 m soil layer in response to the highest PS rate compared to the treatment with no PS. Results also indicated that P added via PS was preferentially accumulated in the inorganic fractions (83-98 %). The increase in organic P was limited by the increase in soil organic carbon. The increase in soil microbial biomass-P was more influenced by available P, while the increase in phosphatase enzyme activity was more related to the increase in organic P and C. Therefore, PS applied to the soil affected the chemical, biological, and biochemical components of the soil P cycle. Results indicate that even half of the PS rate normally used by farmers (20 m3 ha-1) poses a high risk of pollution of water bodies by runoff from these soils.

Resumo: O objetivo deste trabalho foi determinar as alterações em atributos químicos de um Latossolo Vermelho após aplicações sucessivas de composto orgânico de dejeto líquido de suínos com maravalha, em sistema plantio direto. O experimento foi conduzido em Chapecó, SC, em Latossolo Vermelho, de setembro de 2005 a agosto de 2011. Foram aplicadas anualmente as doses de 0, 2, 4, 8 e 16 Mg ha-1 de composto de dejeto líquido de suínos com maravalha, além de um tratamento com adubação mineral (NPK). Após seis aplicações, coletaram-se amostras de solo nas camadas de 0-4, 4-8, 8-12, 12-16, 16-20, 20-40 e 40-60 cm e avaliaram-se os atributos químicos. As maiores doses do composto orgânico incrementaram o pH do solo e reduziram a acidez potencial. As aplicações de composto orgânico derivado de dejeto de suínos e maravalha promoveram alterações nos atributos químicos do Latossolo Vermelho avaliado, especialmente nas camadas superficiais do solo, com maior ênfase para aumento do pH do solo e dos teores de P, K, Cu e Zn. A utilização de 4 Mg ha-1 do composto mantém os atributos químicos do solo semelhantes aos do tratamento NPK, que seguiu recomendação oficial para os estados do Rio Grande do Sul e de Santa Catarina, além de manter os teores de P nas camadas superficiais dentro do limite crítico ambiental para solos com altos teores de argila.

Abstract: The objective of this work was to determine changes in the chemical attributes of an Oxisol after successive applications of organic compounds with pig slurry and wood shavings, under a no-tillage system. The experiment was conducted in the municipality of Chapecó, in the state of Santa Catarina, Brazil, in an Oxisol, from September 2005 to August 2011. The doses of 0, 2, 4, 8, and 16 Mg ha-1 compound with pig slurry and shavings were applied annually, as well as a treatment with mineral fertilizer (NPK). After six applications, soil was collected at the 0-4, 4-8, 8-12, 12-16, 16-20, 20-40, and 40-60-cm layers and the chemical attributes were evaluated. The highest doses of the organic compound increased soil pH and reduced potential acidity. The applications of the organic compound derived from swine manure and wood shavings promoted changes in the chemical attributes of the evaluated Oxisol, especially in the upper soil layers, with greater emphasis on increased soil pH and P, K, Cu, and Zn contents. The use of 4 Mg ha-1 of the compound maintains the soil chemical attributes similar to those of the NPK treatment, which followed official recommendation for the states of Rio Grande do Sul and Santa Catarina, besides keeping the P content in the surface layers within the environmental critical limit for soils with high clay content.

As videiras cultivadas em solos arenosos são submetidas a aplicações de nitrogênio (N), porém são poucas as informações sobre o seu impacto na produção, estado nutricional e a composição do mosto. O trabalho objetivou avaliar a produção, estado nutricional e composição do mosto em videiras submetidas à aplicação de N. Videiras Cabernet Sauvignon foram submetidas à aplicação anual de 0, 10, 15, 20, 40, 80 e 120 kg N ha-1, em 2008, 2009 e 2010. Nas safras de 2008/09, 2009/10 e 2010/11 foram coletadas folhas no pleno florescimento e na mudança da cor das bagas, e analisado o teor de N total, avaliada a produção de uva e no mosto foram determinados atributos enológicos. A resposta à aplicação de N foi pouco expressiva, tanto que a maior produção de uva de Cabernet Sauvignon foi obtida com a aplicação de 20 kg de N ha-1 ano-1. A aplicação de N aumentou o teor do nutriente na folha coletada no pleno florescimento, mas pouco afetou o teor de nutrientes totais no mosto e não interferiu os atributos enológicos do mosto, como os sólidos solúveis, pH, acidez total e ácido málico e tartárico.

Grapevines grown on sandy soils are subjected to the application of supplemental nitrogen (N); however, there is little information available regarding the impact of these applications on yield, plant nutritional state and must composition. The aim of this study was to evaluate the yield, nutritional state and must composition of grapevines subjected to N fertilization. Cabernet Sauvignon grapevines were subjected to annual applications of 0, 10, 15, 20, 40, 80 and 120 kg N ha-1 in 2008, 2009 and 2010. During the 2008/09, 2009/10 and 2010/11 harvest seasons, leaves were collected during full flowering and when the berries changed color, and the total N content was analyzed. The grape yield and the enological characteristics of the must were evaluated. The response to applied N was low, and the highest Cabernet Sauvignon grape yield was obtained in response to an application of 20 kg N ha-1year-1. The application of N increased the nutrient content in the leaf collected at full flowering, but it had little effect on the total nutrient content in the must, and it did not affect the enological characteristics of the must, such as soluble solids, pH, total acidity, malic acid and tartaric acid.

Os dejetos de animais são aplicados no solo como fonte de nutrientes, especialmente nitrogênio, às plantas. Entretanto, as doses dos dejetos podem ser diminuídas com a aplicação de fertilizante nitrogenado em cobertura. Este trabalho objetivou avaliar a resposta de culturas à aplicação de diferentes doses de fontes de dejetos de animais, utilizadas de maneira isolada e complementadas com N mineral em cobertura, sob sistema plantio direto. O trabalho foi realizado no período de 2005 a 2008, sob um Argissolo Vermelho distrófico arênico. Os tratamentos foram: doses de 10, 20 e 30 m³ ha-1 de dejeto líquido de suínos (DLS) e 1 e 2 t ha-1 de dejeto de peru (DP), aplicadas isoladamente e complementadas com adubação nitrogenada em cobertura (ANC), além de dois controles, adubação mineral (NPK) e testemunha, sem aplicação. Foram avaliadas a produtividade de grãos, nas culturas do feijoeiro e milho; a produção de matéria seca; e o acúmulo de nutrientes, nas culturas do feijoeiro, milho e aveia-preta. A aplicação de N em cobertura nas culturas de milho e feijoeiro, especialmente, quando foram utilizados DLS, nas doses de 20 e 30 m³ ha-1, e DP, na dose de 2 t ha-1, se apresentou eficiente no aumento da produtividade de grãos das culturas, demonstrando a viabilidade do uso associado de fontes orgânicas e minerais industrializadas. O acúmulo de N no tecido das culturas de milho e feijoeiro foi o indicador que mais se relacionou com a produtividade de grãos, ao contrário da recuperação aparente de nutrientes que não apresentou relação com as quantidades aplicadas de N, P e K das fontes orgânicas. A aplicação de N em cobertura no milho e no feijoeiro, cultivados com a aplicação de DLS e DP, não evidenciou claramente efeito residual na produção de matéria seca de aveia, cultivada em sucessão.

Animal manure is applied to the soil as a nutrient source, especially of nitrogen, to plants. However, manure application rates can be reduced with the use of N fertilizer in topdressing. The aim of this study was to evaluate crop responses to different application rates of animal manure sources, used alone and supplemented with mineral N topdressing, in a no-tillage system. The study was carried out from 2005 to 2008 on a Hapludalf soil. The treatments consisted of rates of 10, 20 and 30 m³ ha-1 of pig slurry (PS), and of 1 and 2 t ha-1 of turkey manure (TM), applied alone and supplemented with topdressed N fertilizer (TNF), as well as two controls, mineral fertilization (NPK) and one control without fertilizer application. Grain yield in common bean and maize, and dry matter yield and nutrient accumulation in common bean, maize and black oat crops were evaluated. Nitrogen application in topdressing in maize and common bean, especially when PS was used at rates of 20 and 30 m³ ha-1, and TM, at 2 t ha-1, proved effective in increasing the crop grain yields, showing the viability of the combined use of organic and industrialized mineral sources. Nitrogen accumulation in maize and common bean tissues was the indicator most strongly related to grain yield, in contrast with the apparent nutrient recovery, which was not related to the N, P and K quantities applied in the organic sources. No clear residual effect of N topdressing of maize and common bean was observed on the dry matter yield of black oat grown in succession to the main crops with PS and TM applications.

O dejeto líquido de suínos (DLS) representa importante fonte de nutrientes às plantas e sua utilização como adubo para as culturas significa a possibilidade de maior ciclagem de nutrientes no ambiente. Este trabalho objetivou avaliar como as doses de DLS, aplicadas ao longo de alguns anos, podem impactar a produção de grãos, de matéria seca e o acúmulo de nutrientes em culturas de grãos comerciais e em plantas de cobertura do solo. O experimento foi realizado na área experimental da Universidade Federal de Santa Maria, em Santa Maria, RS, no período de maio de 2000 a janeiro de 2008. Nesse período, foram implantadas 19 culturas de grãos e de cobertura de solo, sendo aplicado DLS antes da semeadura de cada cultura, nas doses de 0, 20, 40 e 80 m³ ha-1. O aumento da dose de DLS aplicada ao longo de anos promoveu o incremento da disponibilidade de nutrientes, notadamente de P, mas também de nutrientes que podem ser potencialmente tóxicos às plantas, especialmente Cu e Zn. A recuperação aparente de nutrientes pelas culturas de grãos comerciais e de cobertura do solo diminuiu à medida que aumentou o número de aplicações de doses de DLS no solo. A produção de matéria seca acumulada das culturas e a produção de grãos de milho foram maiores com a dose anual de 80 m³ ha-1 de DLS. Entretanto, a produtividade de grãos de feijão elevou até 20 m³ ha-1 de DLS, evidenciando que, na definição da dose, deve ser considerada a cultura a ser estabelecida.

Pig slurry (PS) represents an important nutrient source for plants and using it as fertilizer makes greater nutrient cycling in the environment possible. The aim of this study was to assess how PS application over a period of years can affect grain yield, dry matter production and nutrient accumulation in commercial grain and cover crops. The experiment was carried out in an experimental area of the Universidade Federal de Santa Maria, in Santa Maria, RS, Brazil, from May 2000 to January 2008. In this period, 19 grain and cover crops were grown with PS application before sowing, at rates of 0, 20, 40 and 80 m³ ha-1. The highest PS rate led to an increase in nutrient availability over the years, notably of P, but also of nutrients that are potentially toxic to plants, especially Cu and Zn. The apparent recovery of nutrients by commercial grain and cover crops decreased with the increasing number of PS applications to the soil. Accumulated dry matter production of the crops and maize grain yield were highest at an annual application rate of 80 m³ ha-1 PS. However, common bean yield increased up to 20 m³ ha-1 PS, showing that the crop to be grown should be considered to define the application rate.

As videiras em produção tendem a aproveitar pequena quantidade do N, derivado do fertilizante mineral, mesmo cultivadas em solos com textura arenosa e baixo teor de matéria orgânica, o que confere a esses solos baixa capacidade de fornecimento de nitrogênio (N). O objetivo deste trabalho foi avaliar, por meio de incubação, a disponibilidade de nitrogênio (N) em solo com histórico de cultivo com videiras e submetido à aplicação de fontes minerais e orgânicas de nutrientes. Foram coletadas amostras de um Argissolo Vermelho, em um vinhedo e em uma área sob campo natural, no município de Rosário do Sul (RS). Após o preparo do solo, foram montados os seguintes tratamentos: solo do campo nativo; solo do vinhedo; solo do vinhedo + composto orgânico; solo do vinhedo + ureia revestida com polímeros e solo do vinhedo + ureia. Os solos foram incubados por 141 dias, e aos 0, 38, 70, 102 e 141 dias de incubação, foram determinados os teores de N-NH4+ e N-NO3-, e calculados os teores de N mineral, mineralização líquida, N mineralizado em relação ao total e o N mineral acumulado. No solo de vinhedo submetido à aplicação de ureia revestida com polímeros e de ureia, a maior mineralização de N aconteceu no período inicial. A liberação de N do composto orgânico tem um maior sincronismo com a necessidade da videira pelo nutriente. As reservas de N total potencialmente mineralizável do solo podem suprir a demanda da videira pelo N.

The objective of this study was to evaluate the nitrogen (N) availability in a soil with history of growing vines and submitted to application of mineral and organic sources of nutrients. In October 2010, samples of a Sandy Typic Hapludalf soil were collected in a vineyard and in a natural pasture soil, in the municipality of Rosario do Sul (RS). The treatments consisted of: natural pasture and vineyard soil as control; vineyard soil + organic compost; vineyard soil + polymer coated urea and vineyard soil + urea. The soils were incubated and subsamples were taken at 0, 38, 70, 102 and 141 days of incubation to determine N-NH4+ and N-NO3- contents. Concentrations of mineral N, net mineralization, N mineralization in relation to the total N and mineral buildup were calculated. In vineyard soils submitted to application of the polymer coated urea and urea, most N mineralization occurred in the initial period. Nitrogen release from the organic compound has better synchronicity with the vine requirements. The soil reserves of total nitrogen potentially mineralized may supply the vine demand for N.

A aplicação de dejetos de animais no solo pode aumentar a disponibilidade de fósforo às plantas e potencializar a transferência do nutriente pela solução escoada ou percolada. Este trabalho objetivou avaliar o efeito de sucessivas aplicações de fontes orgânicas e mineral de nutrientes sobre o teor disponível, o escoamento superficial e a percolação de formas de P em um Argissolo Vermelho manejado sob sistema plantio direto. O experimento 1 foi desenvolvido em 2004 na área experimental do Departamento de Solos da Universidade Federal de Santa Maria, em Santa Maria, RS, sob plantio direto. Os tratamentos foram testemunha (sem aplicação de nutrientes), dejeto líquido de suínos (DLS), cama sobreposta de suínos (CSS), dejeto líquido de bovinos (DLB) e fertilizante mineral (NPK), sendo as doses determinadas para suprir a necessidade de N das culturas. Durante o ano agrícola de 2010/2011 (cultivo de aveia-preta e milho), após cada evento (chuva + escoamento ou percolação), foi coletada solução e determinaram-se os teores de P-solúvel, total e particulado. Em novembro de 2008, amostras de solo foram coletadas estratificadas de 2 em 2 cm, até 20 cm; de 5 em 5 cm, até 40 cm; e 10 em 10 cm, até 70 cm. O solo foi seco, moído e determinado o teor de P extraído pela resina trocadora de ânions (RTA). No experimento 2, os tratamentos foram solo; solo + DLS; solo + CSS; solo + DLB; e solo + NPK. Após 20, 35, 58, 73 e 123 dias de incubação, foram determinados os teores de P extraído por RTA. As aplicações de fontes de nutrientes ao longo dos anos proporcionaram incremento e migração de P-disponível no perfil do solo, refletindo em transferências de P por escoamento superficial e percolação, especialmente no solo com a aplicação de DLS e CSS, onde foi realizada a maior adição do nutriente. Os teores de P disponível no solo e as transferências de P por escoamento superficial correlacionam-se com as quantidades aplicadas, independentemente da fonte de P utilizada. Porém, a transferência de P por percolação não se correlacionou com a quantidade aplicada do nutriente, mas sim com a quantidade de solução percolada no perfil do solo.

The application of animal manure to soil can increase phosphorus availability to plants and enhance transfer of the nutrient solution drained from the soil surface or leached into the soil profile. The aim of this study was to evaluate the effect of successive applications of organic and mineral nutrient sources on the available content, surface runoff and leaching of P forms in a Typic Hapludalf in no-tillage systems. Experiment 1 was set up in 2004 in the experimental area of UFSM, in Santa Maria (RS, Brazil). The treatments consisted of: control (without nutrient application) and application of pig slurry (PS), pig deep-litter (PL), cattle slurry (CS), and mineral fertilizers (NPK). The rates were determined to meet the N crop requirements of no-tillage black oat and maize, grown in the 2010/2011 growing season. The soil solution was collected after each event (rain + runoff or leaching) and the soluble, particulate and total P contents were measured. In November 2008, soil was collected in 2 cm intervals to a depth of 20 cm, in 5 cm intervals to a depth of 40 cm, and in 10 cm intervals to a depth of 70 cm. The soil was dried and ground, and P determined after extraction by anion exchange resin (AER). In experiment 2, samples collected from the Typic Hapludalf near experiment 1 were incubated for 20, 35, 58, 73 and 123 days after applying the following treatments: soil, soil + PS, soil + PL, soil + CS and soil + NPK. Thereafter, the soil was sampled and P was analyzed by AER. The applications of nutrient sources over the years led to an increase in available P and its migration in the soil profile. This led to P transfer via surface runoff and leaching, with the largest transfer being observed in PS and PL treatments, in which most P was applied. The soil available P and P transfer via surface runoff were correlated with the amounts applied, regardless of the P source. However, P transfer by leaching was not correlated with the applied nutrient amount, but rather with the solution amount leached in the soil profile.

As aplicações sucessivas de dejetos líquidos e cama sobreposta de suínos podem provocar o acúmulo de frações de cobre (Cu) e zinco (Zn) no perfil do solo. Este trabalho objetivou avaliar as formas e o acúmulo de Cu e Zn em um Argissolo Vermelho com histórico de aplicação de dejetos líquidos e cama sobreposta de suínos. Em março de 2010, 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; 2,5-5,0; 5-10; e 10-15 cm, em tratamentos sem a aplicação de dejetos 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 em gral de pedra ágata e submetido à análise dos teores de Cu e Zn por EDTA 0,01 mol L-1 e ao fracionamento químico de Cu e Zn. A aplicação de cama sobreposta de suínos e dejetos líquidos de suínos aumentou os teores de Cu e Zn disponíveis na camada superficial do solo; entretanto, quando se aplicaram a dose (equivalente a 90 kg ha-1 de N) e o dobro da dose de cama sobreposta de suínos e o dobro da dose de dejetos líquidos de suínos o Cu e o Zn migraram até 15 cm de profundidade. O Cu no solo é acumulado especialmente na fração orgânica e residual e o Zn, preferencialmente na fração ligada aos argilominerais, especialmente nas camadas mais superficiais.

Successive applications of pig slurry and pig deep litter may lead to an accumulation of copper (Cu) and zinc (Zn) fractions in the soil profile. The objective of this study was to evaluate the Cu and Zn forms and accumulation in a Sandy Typic Hapludalf soil after long-term application of pig slurry and deep litter. In March 2010, eight years after initiating an experiment in Braço do Norte, Santa Catarina (SC), Brazil, on a Sandy Typic Hapludalf soil, soil samples were collected from the 0-2.5, 2.5-5.0, 5-10 and 10-15 cm layers in treatments consisting of no manure application (control) and with applications of pig slurry and deep litter at two levels: the single and double rate of N requirement for maize and black oat succession. The soil was dried, ground in an agate mortar and analyzed for Cu and Zn contents by 0.01 mol L-1 EDTA and chemically fractionated to determine Cu and Zn. The applications of Pig deep litter and slurry at doses equivalent to 90 kg ha-1 N increased the contents of available Cu and Zn in the surface soil layer, if the double of this dose was applied in pig deep litter or double this dose in pig slurry, Cu and Zn migrated to a depth of 15 cm. Copper is accumulated mainly in the organic and residual fractions, and zinc preferentially in the fraction linked to clay minerals, especially in the surface soil layers.

Aplicações sucessivas de dejeto de suínos em solos sob plantio direto podem aumentar os teores de nutrientes em suas camadas superficiais, bem como parte desses podem ser transferidos para as mais profundas. O objetivo deste trabalho foi avaliar a distribuição de nutrientes no perfil de um solo com 19 aplicações de dejeto líquido de suínos em sistema de plantio direto, durante 93 meses. O experimento foi conduzido em área experimental da Universidade Federal de Santa Maria, no período de maio de 2000 a janeiro 2008, em um Argissolo Vermelho distrófico arênico. Os tratamentos consistiram da aplicação de 0, 20, 40 e 80 m³ ha-1 de dejeto líquido de suínos e, no final do experimento, amostras de solo foram coletadas nas camadas 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 e 50-60 cm. Foram determinados os teores de N mineral, P e K disponíveis e os teores totais de N, P e K. As 19 aplicações de dejeto de suínos por 93 meses promoveram o deslocamento de N e P total até 30 cm e P e K disponíveis até a camada mais profunda analisada. Essas 19 aplicações não promoveram incremento no teor de N mineral do solo, mas aumentaram os níveis de P e K disponíveis, demonstrando a transferência de P e K para as camadas mais profundas do que as do limite da amostra. Isso evidencia indesejáveis consequências ambientais e econômicas para o uso de dejeto de suínos e reforça a necessidade de racionalidade na sua utilização, o que envolve o uso de doses menores de dejeto combinado com fertilizantes minerais.

Successive applications of pig slurry to soils under no-tillage can increase the nutrient levels in the uppermost soil layers and part of the nutrients may be transferred to deeper layers. The objective was to evaluate the distribution of nutrients in the profile of a soil after 19 pig slurry applications under no-tillage for 93 months. The experiment was conducted from May 2000 to January 2008 in an experimental area of the Federal University of Santa Maria, southern Brazil, on a Typic Hapludalf. The treatments consisted of pig slurry applications (0, 20, 40 and 80 m³ ha-1) and at the end of the experiment, soil samples were collected (layers 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 and 50-60 cm). The levels of mineral N, available P and K and total N, P and K were evaluated. The 19 pig slurry applications in 93 months promoted migration of total N and P down to 30 cm and available P and K to the deepest layer analyzed. At the end of the experiment, no increase was observed in mineral N content in the deeper layers, but increased levels of available P and K, showing a transfer of N, P and K to layers below the sampled. This evidences undesirable environmental and economic consequences of the use of pig slurry and reinforces the need for a more rational use, i.e., applications of lower manure doses, combined with mineral fertilizers.

A aplicação de dejetos como adubo ao solo pode alterar os atributos químicos deste e afetar a sua acidez, modificando o ambiente para o crescimento e desenvolvimento das culturas. O objetivo deste trabalho foi avaliar a alteração de atributos químicos relacionados à acidez de um solo submetido a aplicações sucessivas de dejeto líquido de suínos. O experimento foi instalado em maio de 2000, em área experimental sob plantio direto pertencente à Universidade Federal de Santa Maria (UFSM) e conduzido até janeiro de 2008. Foram realizadas 19 aplicações superficiais de 0, 20, 40 e 80 m³ ha-1 de dejeto líquido de suínos, durante 100 meses. Ao final, foi coletado solo nas camadas de 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 e 50-60 cm. A aplicação de dejeto líquido de suínos aumentou os valores de pH do solo, podendo o incremento atingir a profundidade de 8 cm, sem alteração nos valores de acidez potencial. Também promoveu acúmulo dos teores trocáveis de Ca e Mg nas camadas superficiais do solo, aumentando os valores de saturação por bases e diminuindo a saturação por Al. As aplicações ao longo do tempo possibilitaram aumento no teor de MO em profundidade. Entretanto, o efeito desses dejetos sobre a CTC potencial foi menos significativo e restrito à camada superficial.

Pig slurry application as soil manure can alter the chemical properties of the soil and affect its acidity, modifying the environment for crop growth and development. The objective of this study was to evaluate the chemical properties related to soil acidity subjected to successive applications of pig slurry. The experiment was conducted in May 2000, in an experimental area of the Federal University of Santa Maria (UFSM) under no-tillage and lasted until January 2008. Nineteen surface applications of 0, 20, 40, and 80 m³ ha-1 of pig slurry were performed, during a period of 100 months and the soil sampled in the end (layers 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 and 50-60 cm). The application of pig slurry increased soil pH values, an effect that could reach the depth of 8 cm without affecting the potential acidity values. The applications also resulted in accumulation of Ca and Mg exchangeable levels in the surface layers, increasing base saturation and reducing Al saturation. Long-term applications induced an increase in organic matter in the deeper layers. However, the effect of this residue on the potential CEC was less significant and restricted to the surface layers.

O objetivo deste trabalho foi quantificar as frações de acumulação de fósforo em solo submetido a sucessivas aplicações de dejetos líquidos de suínos (DLS) em sistema de plantio direto. Em Santa Maria, RS, doses de 0, 20, 40 e 80 m³ ha-1 de DLS foram distribuídas a lanço por sete anos agrícolas, antes do plantio de cada cultivo de inverno ou verão, em Argissolo Vermelho arenoso, totalizando 0, 584, 1.168 e 2.336 kg ha-1 de P aplicado via dejetos. O solo foi coletado nas camadas 0-2, 4-6, 8-10, 14-16 e 20-25 cm, e submetido ao fracionamento químico de P. A adição do DLS ao solo durante sete anos aumentou o teor de P até 25 cm de profundidade, principalmente nas frações inorgânicas extraídas por resina trocadora de ânions, NaHCO3 0,5 mol L-1 e NaOH 0,1 mol L-1. As aplicações não aumentaram os teores de P orgânico extraído por NaHCO3 0,5 mol L-1, mas sim as frações orgânicas extraídas por NaOH 0,5 e 0,1 mol L-1. O DLS adicionado ao solo por longo período pouco afeta a partição de P em frações inorgânicas e orgânicas. As sucessivas aplicações de DLS aumentam o acúmulo de P em frações predominantemente lábeis no solo, o que representa um risco potencial para contaminação de águas superficiais e subsuperficiais.

The objective of this work was to quantify the accumulation of phosphorus fractions in the soil subjected to successive pig slurry applications in a no-tillage system. At Santa Maria, Rio Grande do Sul state, Brazil, 0, 20, 40 and 80 m³ ha-1 doses of pig slurry were broadcasted for seven years on Argissolo Vermelho arenoso (Arenic Hapludult) before sowing each winter or summer crop, totalizing 0, 584, 1,168 and 2,336 kg ha-1 of P from pig slurry. Soil samples were collected in 0-2, 4-6, 8-10, 14-16 and 20-25 cm layers and submitted to P fractionation. Applications of pig slurry during seven years increased P contents to a depth of 25 cm, especially in the inorganic fractions extractable by anion exchange resin, NaHCO3 0.5 mol L-1 and NaOH 0.1 mol L-1. Pig slurry doses did not increase P content in organic fractions extracted by NaHCO3 0.5 mol L-1, but increased the content of organic fractions extracted by NaOH 0.5 e 0.1 mol L-1. Pig slurry applied to soil for large period has little effect on the P partition in inorganic and organic fractions. Successive pig slurry applications increase P contents in the soil predominantly in labile fractions, which can represent a potential risk for waterbeds contamination.