ABSTRACT Phosphorus availability in soils is low due to its strong retention by inner-sphere complexation on minerals in the clay fraction with pH-dependent charges, such as goethite. On the other hand, sulfur has greater availability because it is retained mainly by electrostatic attraction. We evaluated the intensities of the inner-sphere complexation of orthophosphate and sulfate (H2PO4-/HPO42- and SO42- - generically treated as PO4 and SO4) under different experimental conditions (pH, goethite purity, and contact times) on synthetic goethite samples to establish the mechanisms and models involved in those bonds. Inner-sphere PO4 and SO4 were extracted using both HNO3 1 mol L-1 and USEPA 3051A methods. Inner-sphere complexation of PO4 and SO4 was highest at pH 5 in relation to pH 9. Attenuated total reflectance/Fourier transform infrared spectroscopy (ATR-FTIR) spectra showed inner-sphere complexation bands of PO4 on goethite in the protonated binuclear bidentate (pH 5) and deprotonated binuclear bidentate (pH 9) forms. Inner-sphere complexation of PO4 was much more expressive than that of SO4. Phosphorus and sulfur oxyanions displace the diprotonated ferrol ligand (-OH2+0.5 in -FeOH2+0.5), while the -OH-0.5 in the -Fe-OH-0.5 group are only displaced by PO4. The -O-1.5 ligand in Fe-O-1.5 group is not displaced by PO4 or SO4. The high surface negative charge density of PO4 defined its higher activation energy for exchanging -OH2+0.5 and -OH-0.5 on the goethite surface in relation to SO4. The proposed model can be used to reduce inner sphere phosphate adsorption in soils and improve P fertilization efficiency for farming.

Abstract Fertilization can be a sustainable management practice for the maintenance of the threatened species such as Araucaria angustifolia. Our objective was to evaluate the elemental composition of A. angustifolia fertilized with N, P, and K, and how the fertilization altered the soil fertility. Seven-month-old seedlings were transplanted to 16 dm3 soil pots, and three experiments were carried separately (one for each cited element) in a completely randomized design. Overall, the seedlings tended to accumulate nutrients differently among the compartments in the following order: needles > branches > stem. Application of N reduced the soil pH, boosted Mn concentration in more 10 times, decreased the P uptake, and changed the C:N and C:P ratios. Increased doses of P led to higher uptake rates but promoted a reduction in the absorption of Mg. High rates of K diminished of P, Ca, Mg, Mn, and B, confirming antagonism interaction with Ca and Mg.

Abstract Swine manure is applied in agricultural fields as a source of nutrients for plant growth, however, excessive application over the years can promote soil phosphorus (P) accumulation. The objective of this study was to establish the environmental soil P threshold based on the degree of P saturation (DPS), as well, to evaluate the soil P storage capacity. The experiment was carried out in an Oxisol (sandy clay loam texture), under no-tillage and crop rotation. Treatments consisted of four annual doses of liquid swine manure (0, 100, 200, and 300 m3 ha-1 year-1), and three doses of mineral fertilizer (0, 50, and 100% of the crop nutrients requirement), in a randomized block with split-plot design (four replications). Soil P content was analyzed by PMehlich-1, PCaCl2, water-soluble P (WSP) and total P. The application of swine manure and mineral fertilizer increased soil P contents mainly at 0-10 cm depth. The DPS corresponding to the change point was 14.9% at depth 0-10 and 8.6% at depth 0-20 cm with WSP and 18.7% at 0-10 cm and 8.9% at 0-20 cm depth with PCaCl2. The lowest change point value was DPS 8.6% which corresponds to 43 mg kg-1 of PMehlich-1, so, in practical terms, we suggest this value as the environmental soil P threshold. The soil P storage capacity indicated negative values with the higher doses of swine manure and mineral fertilizer which increases the vulnerability of P loss by surface and subsurface hydrological transfer pathway.

ABSTRACT Residual biomass from grains has potential as an energetic source. Biomass composition determines this potential and is related to plant nutrition, which may vary according to soil fertility. The aim of this 23-year field study was to evaluate changes in chemical attributes of a Brazilian Oxisol and in the energetic potential of oat (Avena sativa L.) and soybean (Glycine max (L.) Merr) residual biomasses provided by tillage systems and fertilizer rates. The trial was performed since 1989, assessing soil chemical attributes in no-tillage (NT), conventional (CT), minimum (MT) and no-tillage plus chisel plough (NT+CP), with two fertilizer rates (normal and reduced, since 1994). Oat and soybean (2012/2013) residual biomasses were collected and analyzed by its elemental composition, higher heating value (HHV) and theoretical potential for electricity production. The NT system presented higher P-resin availability; NT and NT+CP provided higher OM and total P content on soil surface. Without appropriate amounts of K and P fertilizer, P-resin and P total contents diminished mainly in 0-0.1 m depth, while exchangeable, non-exchangeable and total K+ fractions were mined even in deeper layers (0-0.3 m). The better general fertility conditions were achieved by conservative tillage systems, with normal fertilizer rate. Soil fertility levels changed chemical composition of both biomasses but had no effect on biomass HHV. Considering a system with oat and soybean grain production plus residual biomasses for energetic exploitation, it could be possible to generate 2,941 GWh·year–1, while still achieving 70% residue coverage under no-tillage maintenance.

RESUMO. Alta disponibilidade de Al demanda maiores cuidados para tornar os solos aptos para a agricultura devido a toxidez para as plantas cultivadas. Contudo, as pesquisas sobre a relação entre a distribuição de Al em profundidade e o intemperismo do solo têm sido pouco priorizadas, principalmente aquelas conduzidas com um maior número de perfis de solos. O presente estudo analisou-se 38 solos ácidos selecionados dos levantamentos de solos da região Sul do Brasil, com o objetivo de identificar e isolar o efeito dos componentes orgânicos e minerais na distribuição em profundidade do Al trocável extraído com KCl (AlKCl). A seleção resultou na formação de três grupos de solos em relação aos teores de AlKCl em profundidade: Grupo I - diminuição; Grupo II - inexpressiva variação e; Grupo III - aumento. A matéria orgânica foi mais importante para determinar os altos teores de AlKCl na superfície dos solos mais intemperizados (grupo I) e a qualidade da fração mineral definiu os elevados teores de AlKCl nos horizontes subsuperficiais do grupo III. A distribuição de AlKCl em profundidade foi definida pelo grau de intemperismo do solo. O conhecimento desses agrupamentos de solo pode auxiliar no manejo da acidez do solo para otimizar a produtividade das culturas no sul do Brasil.

ABSTRACT. Due to potential crop toxicity, high aluminum (Al) availability requires increased attention when preparing agricultural soils. However, research examining the relationship between depth distribution of Al and soil weathering has received little priority in Brazil, particularly regarding the number of soil profiles investigated. This study analyzed 38 acid soils selected from Soil Surveys in southern Brazil to identify and isolate the effects of organic and mineral components on depth distribution of exchangeable Al extracted with KCl (AlKCl). These soil profiles were divided into the following three groups based on AlKCl depth distribution: Group I - decrease with depth; Group II - little variation with depth; and Group III - increase with depth. High AlKCl found near the surface of well-developed soils (Group I) was influenced by organic matter content, while mineral fraction quality defined the occurrence of high AlKCl in subsurface horizons of Group III. The depth distribution of AlKCl was defined by the degree of weathering in these subtropical soils. Possessing a knowledge of these soil groupings may aid in soil acidity management to optimize crop productivity in southern Brazil.

ABSTRACT Many Amazonian farmers use the slash-and-burn method rather than fertilization for crop production. The aim of the present study was to evaluate changes in the morphological, physical, and chemical properties of naturally fertile Inceptisols after conversion from native forest to different uses in southern Amazonia, Brazil. Land covered by dense native forest (NF) was split into four areas of 1.0 ha each. Three areas were slashed and burned and then cultivated for 11 years with coffee (CO), secondary forest (SF), and pasture (PA). Four soil profiles were sampled in each treatment (four uses × four replicates). The mean value distribution of each physical and chemical analysis was determined for different depths, and standard error bars were placed to display significant differences among treatments. Results showed that morphology and physical properties were negatively affected after the establishment of PA and CO: a reduction in the thickness of the A horizon and in aggregate stability, a decrease in total porosity and macroporosity, and an increase in aggregate size and bulk density. Soil bulk density (SBD), geometric mean diameter of water-stable aggregates (GMD), and microporosity (SMi) were higher in soil under pasture as a consequence of more intense soil surface compaction. Native and secondary forests were the only treatments that showed granular structures in the A horizon. Significant differences between native forest and secondary forest were mainly found in the top soil layer for total porosity (STP) (NF>SF), macroporosity (SMa) (NF>SF), SBD (NF>SF) and GMD (SF>NF). Phosphorus contents in the A horizon increased from 6.2 to 21.5 mg kg-1 in PA and to 27.2 mg kg-1 in SF. Soil under coffee cultivation exhibited the lowest levels of Ca2+ and sum of bases in surface horizons. In all slash-and-burn areas there was a reduction in the C stock (Mg ha-1) of the A horizon: native forest 6.3, secondary forest 4.5, pasture 3.3, and coffee 3.1.

Resumo Avaliaram-se os efeitos de níveis de correção da fertilidade do solo (testemunha, calagem, adubação e calagem + adubação) e da idade de rebrota (21, 28, 35, 42, 49, 56, 63, 70, 77 e 84 dias) sobre a dinâmica de crescimento e rendimento de forragem de Trachypogon plumosus em Roraima. O aumento da idade de rebrota resultou em maiores rendimentos de matéria seca (MS), taxa absoluta de crescimento (TAC), taxa de assimilação líquida (TAL), razão de área foliar (RAF) e índice de área foliar (IAF), ocorrendo o inverso quanto à taxa média de crescimento (TMC). A gramínea mostrou-se responsiva à melhoria da fertilidade do solo. A calagem + adubação ou a adubação proporcionaram maiores rendimentos de MS (1.934 e 1.661 kg ha-1), TAC (36,6 e 31,5 kg ha-1 dia-1), TMC (32,5 e 27,9 kg ha-1 dia-1), TAL (4,993 e 4,152 g/m2), RAF (152,9 e 140,9 cm2/g) e IAF (2,42 e 2,14). Para otimizar a eficiência de utilização da forragem produzida e reduzir perdas por senescência da gramínea, o período mais adequado de sua utilização, durante o período chuvoso, situa-se entre 56 e 63 dias com o uso de adubação e calagem + adubação e entre 63 a 70 dias para a testemunha e a calagem.

Abstract We assessed the effects of levels of soil fertility correction (control, liming, fertilization and liming + fertilization) and of regrowth ages (21, 28, 35, 42, 49, 56, 63, 70, 77, and 84 days) on growth dynamic and forage yield of Trachypogon plumosus in the Roraima´s savannas. Dry matter (DM) yields, absolute growth rate (AGR), net assimilation rate (NAR), and leaf area ratio (LAR) increased consistently with regrowth age, while the crop growth rate (CGR) was inversely proportional to regrowth age. The grass showed high responsivity to soil fertility improvement. Liming + fertilization or fertilization alone provided higher DM yields (1,934 and 1,661 kg ha-1), AGR (36.6 and 31.5 kg ha-1.day), CGR (32.5 and 27.9 kg ha-1.day), NAR (4.993 e 4.152 g/m2), LAR (152.9 and 140.9 cm2/g), and LAI (2.42 and 2.14). Regrowth intervals of 56 to 63 days for liming + fertilized and fertilized pastures, and 63 to 70 days for control or liming pastures were appropriate to provide maximum forage yields, growth rates and to prevent larger losses relative to senescence and leaf death.

Solos com alta acidez e baixos teores de bases trocáveis podem ser a causa da baixa produtividade de plantios de Pinus taeda, em Jaguariaíva, PR, Brasil. O objetivo deste estudo foi avaliar o efeito da calagem e adubação aplicadas sobre a serapilheira, em duas áreas com Pinus taeda. Foram avaliadas as concentrações de K+, Ca2+ e Mg2+ no solo, serapilheira e acículas, além dos parâmetros da acidez do solo. Sete tratamentos foram aplicados: (i) completo (N, P, K, Zn, Cu, B, Mo e calagem); (ii) omissão de N, P e K; (iii) omissão de Zn, Cu, B e Mo; (iv) omissão de K; (v) omissão de Zn; (vi) omissão de calagem; (vii) controle. As amostras de solo foram coletadas nas profundidades de 0-5, 5-10, 10-20, 20-40 e 40-60 cm, simultaneamente às amostras de serapilheira. Foram coletadas amostras de acículas do primeiro e segundo lançamentos. A calagem induziu ao aumento do pH, Ca2+ e Mg2+ no solo, ocorrendo o oposto com os teores de Al3+ e saturação por Al. A adubação promoveu incremento nos teores de K+ no solo, serapilheira e acículas. Não ocorreu variação nas concentrações de Ca e Mg nas acículas em relação aos tratamentos.

Soils with high acidity and low exchangeable bases may be responsible for low yields of Pinus taeda in a forest plantation at Jaguariaíva, Paraná State, Brazil. The aim of this study was to evaluate the effect of liming and fertilisation, applied over litter, on two selected areas with Pinus taeda plantations. Soil, litter and pine needles were evaluated for K, Ca and Mg concentrations and soil acidity parameters. Seven treatments were applied: (i) complete (N, P, K, Zn, Cu, B, Mo, and lime); (ii) without N, P, and K; (iii) without Zn, Cu, B, and Mo; (iv) without K; (v) without Zn; (vi) without lime; and (vii) control (without nutrients and lime). Soil samples were collected at five soil depths (0-5, 5-10, 10-20, 20-40 and 40-60 cm) simultaneously with litter samples. Needles were also collected from the first and second pine flushes. Liming induced soil pH, Ca2+, and Mg2+ increases, and the opposite was observed for Al3+ and Al saturation. Fertilisation increased soil exchangeable K+ concentrations and needle and litter K concentrations. The low Ca and Mg concentrations found in the plant needles might be attributable to their low mobility.

O resíduo líquido da indústria de enzimas (LWE) é utilizado como fertilizante por muitos agricultores. Para determinar o impacto do uso de LWE no solo, crescimento e nutrição mineral do pasto nativo, foi executado um experimento com cinco doses de LWE (0, 45, 90, 135 e 180 m³ ha-1), aplicado em um Cambissolo Háplico distrófico, em agosto de 2006. Em 2007 uma única dose de 60 m³ ha-1 foi aplicada em todos os tratamentos. Amostras de solo foram coletadas em quatro profundidades (0-10, 10-20, 20-40 e 40-60 cm) para verificar mudanças nas propriedades químicas do solo. Foram executados cinco cortes para determinar condições nutricionais e produtividade das plantas. No solo constatou-se melhoria nos parâmetros de acidez e disponibilidade de Ca2+, Mg2+, K+ e P, indicando sua ação como corretivo da acidez e fonte de nutrientes. Houve melhoria na qualidade da pastagem através do aumento dos teores de N, K e P nas plantas. O uso de doses do resíduo proporcionou aumentos médios na produtividade (42,6 kg matéria seca m-3 resíduo). Os resultados obtidos indicam que o LWE mostrou-se viável na fertilização de pastagem em Cambissolo ácido de baixa fertilidade.

Farmers have used liquid waste from the enzyme industry as fertilizer. To determine the impact of liquid waste from enzymes (LWEs) on soil properties, plant growth and nutrient content in pasture, an experiment was conducted with five different rates of LWE application (0, 45, 90, 135 and 180 m³ ha-1) to a Cambisol in August 2006. In August 2007, 60 m³ ha-1 of LWE was applied in every treatment. Soil was sampled on four different dates and at four different depths (0-10, 10-20, 20-40 and 40-60 cm) to verify changes in its chemical properties. Soil was improved in terms of acidity and availability of Ca2+, Mg2+, K+ and P in the 0-10 cm layer, indicating that the effect of LWE is corrective concerning these attributes. There was also improvement in pasture quality through increased levels of N, P and K in plants during the first year of waste application. The use of larger doses of LWE led to increases in productivity (42.6 kg dry weight m-3 residues). These results indicate that the application of LWE is feasible for the fertilization of this grassland containing low-fertility acidic Cambisol.

Para o uso agrícola do lodo de esgoto higienizado por processo de estabilização alcalina prolongada (lodo EAP), além de estabelecer limites de aplicação máxima conforme a legislação, é necessário estudar atributos dos lodos e dos solos que favoreçam as metodologias de sua recomendação. Objetivou-se determinar a taxa de aplicação máxima anual (TAMA) de lodo EAP pelo critério de elevação do pH para 20 lodos e solos do estado do Paraná; determinar a influência dos atributos desses solos nos valores da TAMA de lodo EAP; avaliar o uso dos métodos de saturação por bases (V%) e pH referência (SMP), utilizando como padrão o método da incubação. Empregou-se o ensaio de incubação para lodo EAP aplicado ao solo, conforme metodologia oficial. Os resultados indicam que as TAMA de lodo EAP variaram de 10 a >80 Mg.ha-1 para as 20 regionais estudadas; Os atributos químicos (capacidade de troca de cátions, H+Al e carbono) e físico (argila) são os que melhor definem a determinação da TAMA, apresentando relação diretamente proporcional. Os métodos do V% e do pH referência (SMP) para pH H2O 5,5 mostraram-se seguros quanto à recomendação agrícola.

For agricultural use of alkalinized sludge (AS), beyond to establish the maximum application limits to comply with the legislation, it is necessary to study the attributes of sludges and soils that favor the methodologies of its recommendation. The objectives of this study were to determine the maximum annual application rate (MAAR) of alkalinized sludge (AS) according to the pH elevation criterion for 20 sludge origins and soils of the Paraná state; to determine the influence of soil attributes over the MAAR of AS; to evaluate two methods rate calculation for AS, the base saturation (V%) and pH reference (SMP) by comparing with the standard incubation methodology for AS sludge application. It was used incubation test for AS applied to soil, following official methodology. The results indicated that the MAAR were ranged 10 to >80 Mg.ha-1, for the 20 regions; the chemical properties (cation exchange capacity, H+Al and carbon) and physical properties (clay) were the best parameters to the determination of the MAAR, showing direct relationship; the V% and SMP (pH H2O 5,5) methods were safe to the agricultural recommendation.

As altas temperaturas ocorrentes durante a queima na floresta Amazônica podem induzir transformações mineralógicas da fração argila. Este trabalho objetivou avaliar as alterações mineralógicas nas frações areia, silte e argila e na reserva mineral de solos submetidos a diferentes manejos (11 anos de mata secundária, pastagem e café) após a derrubada e queima de floresta nativa situada na Amazônia Meridional, município de Cacoal (RO). Uma área de floresta nativa ombrófila densa, com mesma feição pedológica, foi dividida em quatro partes, sendo três áreas submetidas ao corte e à queima e posteriormente cultivadas. Em cada manejo, os perfis de solos foram descritos e amostras dos horizontes A, AB, B1, 2B2 e 2BC foram coletadas para as análises mineralógicas das frações argila, silte e areia (difratometria de raios X) e químicas da fração argila (extração de Fe com ditionito-citrato-bicarbonato - DCB e com oxalato de amônio - OA). Os teores de K não trocáveis foram determinados nas amostras de solo após extração com HNO3 1 mol L-1 fervente. Verificou-se o predomínio da caulinita na fração argila e alta reserva mineral de K nos solos, associada à ocorrência de mica nas frações argila, silte e areia. Os diferentes manejos não afetaram os teores de Fe2O3DCB e Fe2O3OA; por outro lado, o maior valor estimado para a relação entre os teores de goethita e hematita [Gt/(Gt+Hm)] na fração argila no horizonte A da floresta indica uma possível transformação parcial de Gt em Hm durante a queima da floresta para a implantação dos manejos mata secundária, pastagem e café.

The high soil temperatures that take place during the burning of the Amazon rainforest may induce soil mineralogical transformations. This study aimed to evaluate mineralogical changes in sand, silt and clay fractions and to assess K reserve of soils submitted to different managements (11 years of secondary forest, pasture and coffee plantation) after slashing and burning of a native forest in the Southern Amazon, Cacoal, Rondônia State, Brazil. An area of ombrophilous dense native forest with homogeneous pedologic features was divided into four parts, being three of them submitted to slash and burn and then cropped. In each area, soil profile was described and the A, AB, B1, 2B2 and 2BC horizons were sampled. Mineralogical analyses of clay, silt and sand fractions were performed by X ray diffraction. Clay fraction was also submitted to selective solvent with citrate-bicarbonate-dithionite (CBD) and ammonium oxalate (AO). The soil contents of non-exchangeable K was extracted by boiling with 1 mol L-1 HNO3. Soil mineralogical analysis indicated that kaolinite was the predominant mineral in the clay fraction. There was also evidence of a large reserve K, associated to the occurrence of mica in clay, silt and sand fractions. Chemical analysis indicated that land use did not change the concentration of Fe2O3CBD and Fe2O3AO. However, the highest goethite/hematite ratio [Gt(Gt+Hm)] calculated for the A horizon of the forest soil suggests that the burning favored the partial transformation of goethite in hematite into those areas where it was carried out.

A produção de gado de leiteiro no sul do Brasil ocorre em grande parte em sistema de semi ou completo confinamento dos animais, o que gera uma produção significativa de resíduos. Os resíduos gerados vêm sendo utilizados como única fonte de nutrientes ou associados a fontes minerais na produção de grãos e silagem, mas sua influência nas características de solo não tem sido bem caracterizada. Este trabalho foi realizado com o objetivo de avaliar a influência de doses de adubação com esterco líquido de gado leiteiro, associadas com adubação mineral, sobre os níveis de P, K, C e condutividade elétrica (CE) de um Latossolo Bruno, em sistema plantio direto e rotação de culturas de inverno e verão (sorgo/aveia-preta/milho/azevém/milho/azevém), para produção de silagem, nas camadas de 0-5, 5-10, 10-30, 30-50 e 50-80 cm de profundidade. Os tratamentos foram distribuídos em três blocos casualizados, divididos em 12 parcelas cada bloco, em arranjo fatorial 3 x 4, sendo três níveis de adubação mineral (0, 50 e 100 % da dose recomendada para as culturas) e quatro níveis de adubação orgânica (0, 30, 60 e 90 m³ ha-1 ano-1). A adubação mineral proporcionou maiores valores de P disponível (Mehlich-1 e resina) até a profundidade de 10 cm, dada a adição em profundidade pela plantadeira, enquanto, com esterco aplicado em superfície, os maiores valores ficaram restritos à profundidade de 0-5 cm. Constatou-se esgotamento de K ao longo do perfil devido à elevada extração via silagem, tendo o esterco líquido aplicado uma relação linear com teor de K disponível, em todas as profundidades analisadas. A ausência de efeito da adubação mineral sobre o K deve-se, provavelmente, à baixa dose de K adicionada. Foi observada relação direta entre doses de esterco e teores de C orgânico na camada de 0-5 cm, o mesmo não sendo observado quando do uso de adubo mineral. Baixos valores de CE sugerem grande exportação de nutrientes pela produção de silagem. Os resultados obtidos indicam que não houve movimentação significativa de P no perfil do Latossolo, mesmo após seis anos sob altas doses de esterco de gado leiteiro, e que o K aplicado via esterco e adubação mineral não é suficiente para manter os níveis deste nutriente em sistemas em que a extração de K pela silagem é alta. Nessas situações, o aumento dos teores de C orgânico é restrito à camada superficial do solo em plantio direto e diretamente relacionado com a dose de esterco aplicada.

Dairy cattle in South Brazil is raised mainly in a system based on partial or total confinement of the animals, generating a significant amount of residues. The residues have been used as the only nutrient source or associated to mineral sources in grain or silage production. Their effect on soil characteristics has however been little explored. This study was conducted to evaluate the influence of fertilization rates with liquid dairy cattle manure associated with mineral fertilizer on P, K, C, and electrical conductivity (EC) levels of a Brown Oxisol, under no-tillage and winter and summer crop rotation (sorghum/black-oat/corn/ryegrass/corn/ ryegrass) for silage production, in the layers 0-5, 5-10, 10-30, 30-50 and 50-80 cm. The treatments were distributed in three randomized blocks, each divided in 12 plots, in a 3 x 4 factorial arrangement, with three mineral fertilizer levels (0, 50 and 100 % of the dose recommended for the crops) and four organic fertilizer levels (0, 30, 60, and 90 m³ ha-1 year-1). Mineral fertilizer resulted in higher values of available P (Mehlich-1 and resin) to a depth of 10 cm, due to the fertilizer application in depth by the planter, whereas the highest values under manure surface application were restricted to the 0-5 cm layer. Potassium depletion was observed along the soil profile due to high extraction by silage, and a linear ratio with available K level could be applied in the case of liquid manure at all depths. The lack of effect by the mineral fertilizer on K is probably due to the low rate of K application. A direct relationship was observed between manure rates and organic C concentration in the 0-5 cm layer, unlike in the case of mineral fertilizer. Low EC values were obtained suggesting high nutrient exportation by silage production. Results indicate that there was no significant P migration in the Oxisol profile, even after six years of dairy cattle manure application at high rates, and that K applied via manure and mineral fertilizer is insufficient to maintain the levels of this nutrient in systems where K extraction by silage is high. In these situations, increased levels of organic C are restricted to the soil surface layer in no-tillage and directly related to the manure rate.

O uso de dejetos de animais na produção agrícola pode ocasionar a contaminação ou poluição das águas por nutrientes, principalmente com aplicações consecutivas na mesma área. Nesse sentido, o objetivo deste trabalho foi avaliar o efeito da aplicação de dejeto líquido de bovinos e fertilizantes minerais na lixiviação de NH4+, NO3-, P e K. Para essa avaliação, foram coletadas colunas indeformadas de solo, num experimento de campo que estava sendo conduzido por sete anos consecutivos e que continha 12 tratamentos, resultantes da combinação de quatro doses de dejeto líquido de bovinos com três doses de fertilizante mineral. O experimento de campo era conduzido num Latossolo Bruno distrófico em sistema de plantio direto com sorgo, milho, aveia-preta e azevém em rotação. Em laboratório, essas colunas, de acordo com os respectivos tratamentos de campo, foram submetidas à aplicação do dejeto líquido de bovinos (0, 30, 60 e 90 m³ ha-¹, aplicados em dose única) e dos fertilizantes minerais (0, 50 e 100 % da dose recomendada para o milho - 120, 60 e 60 kg ha-1 de N, P2O5 e K2O). Imediatamente após a aplicação de dejeto e fertilizante, a água percolada por coluna foi coletada e analisada em cinco turnos contínuos, totalizando 516 mm - aproximadamente três volumes de poros. Constatou-se aumento nas concentrações de N-NH4+, P e K com as doses de dejeto e aumento de N-NO3- e K com as doses de fertilizante mineral. No entanto, com exceção do N-NO3-, as concentrações de N-NH4+ e P estiveram abaixo do limite máximo permitido pela legislação brasileira, indicando a importância da infiltração de água no solo na redução do potencial poluidor dos dejetos.

The use of animal manure in agricultural systems can cause water contamination and/or pollution by nutrients, especially by consecutive applications to the same area. In view thereof, the purpose of this study was to evaluate the effect of manure and fertilizer application on NH4+, NO3-, P and K leaching. For this evaluation, undisturbed soil columns were collected from a seven-year field experiment that consisted of 12 treatments, resulting from the combinations of four doses of dairy slurry with three doses of mineral fertilizers. The study has been conducted on an Oxisol under no-till system with a crop rotation including sorghum, corn, oat and ryegrass. The leaching experiment was conducted in a laboratory with the undisturbed soil columns collected in the field experiment. In the laboratory, these soil columns, analogously to the respective field treatments, were treated with dairy slurry manure (0, 30, 60 and 90 m³ ha-¹ applied in a single dose) and mineral fertilizers (0, 50 and 100 % of the recommended dose for corn - 120 kg of N, 60 kg of P2O5 and 60 kg of K2O per ha) application. Immediately after manure and fertilizer application, the percolated water was sampled and analyzed in five continuous periods, totalling 516 mm, which corresponded to approximately three pore volumes. An increase of NH4-N, P, and K with increasing manure doses and an increment in NO3-N and K with the higher mineral fertilizer doses was observed. However, in general, except for NO3-N, the NH4-N and P concentrations were below the limit value determined by the Brazilian legislation, indicating the importance of soil-water infiltration to reduce the manure pollution potential.

O álamo (Populus spp.) apresenta rápido crescimento e vem sendo empregado comercialmente no Sul do Brasil desde meados dos anos de 1990. Pelo espaçamento utilizado em seu plantio, é consorciado com a pastagem, contribuindo para o melhor uso do solo e abatimento do custo da madeira. Visando potencializar o crescimento de culturas de inverno e do álamo em sistema integrado, foi testada a adubação nitrogenada no Município de São Mateus do Sul, PR. O experimento foi instalado em um solo orgânico, testando-se cinco doses de N (0, 20, 40, 80 e 160 kg ha-1) repetidas quatro vezes, na forma de uréia aplicada na cultura consorciada de inverno, que foi a aveia-preta (Avena strigosa Schreb) e o azevém (Lolium multiflorum Lam.), em delineamento inteiramente casualizado. Os resultados indicaram que, após dois períodos de crescimento, as árvores não apresentaram diferenças significativas quanto às variáveis circunferência à altura do peito (cap) e altura total. Para a matéria seca de aveia e azevém, houve acréscimo linear na produtividade em função das doses de N. Pode-se concluir que na idade de 8 anos a fertilização antecipada não traz benefícios, pelo menos nos primeiros anos de sua aplicação.

Poplars (Populus spp.) have been growing as commercial forest crop in southern Brazil since the last decade. To improve soil use and reduce wood cost, poplar has been integrated with grazing cattle. Two major characteristics contribute for the integration of poplar with grazing cattle: the low plant density and the absence of leaves during the winter. Aiming to enhance the quality of food supply and forage to cattle, as well as tree growth within integrated system, a three-year fertilization trial was evaluated, using an eight-year old poplar plantation, located in São Mateus do Sul - PR. Five N rates (0, 20, 40, 80 and 160 kg ha-1. yr), in urea form, were applied to black oat (Avena strigosa Schreb), in 2003, and ryegrass (Lolium multiflorum Lam.), in 2004 and 2005, submitted twice to direct grazing. The N application to the winter crop did not increase poplar growth (tree height and circumference at breast height after two years), suggesting a low residual effect of N. However, the N application promoted a linear increment of dry matter yield for both winter grazing pasture for three years. In addition, an increment of nutrient concentration in the forage was noticed, indicating an improvement in forage quality, especially N. The increment in dry matter yield and/or nutrient concentration in the winter forage increased the nutrient uptake and nutrient cycle. So, the earlier N addition to winter crop was not able to enhance poplar growth, at least in the initial years of evaluation, but the nutrient cycling and the weight gain of livestock with better pasture could bring benefits for poplar culture in the long run.

A mariposa-oriental Grapholita molesta Busck (Lepidoptera: Tortricidae) é uma das pragas-chave do pessegueiro no Estado do Paraná, danificando frutos e ramos. O objetivo deste estudo foi avaliar a flutuação populacional e os danos provocados por G. molesta em pomares cultivados nos sistemas de produção convencional (PC) e integrada (PI) no município da Lapa (PR). A área experimental foi cultivada com pessegueiro 'Chimarrita' e o monitoramento do inseto, realizado com armadilhas de feromônio do tipo Delta, no período de 2002 a 2004. Foram avaliados os danos nos frutos em três fases fenológicas do pessegueiro e a flutuação populacional da praga, relacionando-os com a tomada de decisão de controle. Mediante o monitoramento da praga, reduziu-se em 58% a aplicação de inseticidas no sistema PI em relação ao convencional, e os danos não diferiram em ambos os sistemas. Conclui-se ser possível o manejo de G. molesta em pomares cultivados no sistema de produção integrada na região de Lapa, Paraná.

Larvae of the oriental fruit moth Grapholita molesta is one of the most important pest of peaches orchards in Paraná State, causing fruit and branch damages. The objective of this research was to assess the fluctuation of G. molesta and damage caused by at three phenological phases of peach orchards managed using the conventional (CP) and integrated production (IP) management systems in the municipatility of Lapa, State of Paraná, Brazil, from 2002 to 2004. The experimental area was cropped with the 'Chimarrita' peach tree and the pest was monitored with Delta type pheromone traps. Fruit damage and pest fluctuation were assessed at three phenological stages of the orchard and related to the decision for control. The results showed that the monitoring permitted a 58% reduction in insecticides in the IP system compared to the conventional system. However, the damage was not significantly different between the two systems. It is concluded that it is possible to manage G. molesta in orchards using the integrated production system in that region .