ABSTRACT Objective: To estimate the rate of change during exercise and during recovery in moderate-continuous exercise (MCE) and high-intensity intermittent exercise (HIIE) in children and adolescents with type 1 diabetes (T1D). Subjects and methods: Participants performed 2 sessions of exercise: thirty minutes of continuous activity on a cycle ergometer (60% of VO2max) and thirty minutes (60% VO2max) interspersed with five bouts of maximum intensity lasting ten seconds every five minutes. Capillary blood glucose was measured before and after each test. The glucose rate of change in exercise (RoCE) was calculated (final blood glucose – onset blood glucose/exercise time), and the glucose rate of change in recovery (RoCR) (blood glucose 30 minutes after exercise – end of exercise blood glucose/recovery time). Results: The study included thirty-one participants (aged 13 ± 1.88 years). A lower blood glucose reduction was observed in the HIIE group, as well as better recovery values before, after, and thirty minutes after the test, respectively (333.14 ± 69.53, 226.19 ± 68.05 and 201.77 ± 66.84 versus 211.36 ± 91.03, 155.98 ± 82,68 and 165.76 ± 72.94). Covariance analyses showed a significant difference in glycemic variation between continuous and intermittent protocols immediately after exercise (−2.90 versus −2.08) and during the recovery period (−0.677 versus −0.389). Conclusions: HIIE led to a lower glucose reduction rate per minute during exercise and better recovery in the first 30 minutes after exercise compared to MCE in children and adolescents with T1D.

RESUMO A fertilização com nitrogênio é essencial para a produtividade e qualidade do trigo, mas precisa ser mais precisa, e o uso de sensores ópticos proximais no campo pode auxiliar neste objetivo. O objetivo deste estudo foi avaliar se é possível estimar com o índice de vegetação por diferença normalizada (NDVI), obtido durante a fase de crescimento do trigo, a produtividade de grãos e a qualidade tecnológica da farinha de cultivares submetidas a doses de nitrogênio. O experimento foi conduzido a campo no município de Ponta Grossa, PR, Sul do Brasil. O delineamento experimental foi em blocos casualizados em esquema fatorial 4 × 6 com quatro repetições. Foram avaliadas as cultivares Quartzo, Gralha Azul, Sinuelo e Toruk, combinadas com seis doses de N (0, 40, 80, 120, 160 e 200 kg ha-1 de N). Os valores de NDVI foram sensíveis tanto às doses de nitrogênio quanto às diferentes cultivares. Houve relação do NDVI com a produtividade de grãos e teores de proteína e glúten da farinha. A força de glúten, estabilidade, tenacidade, extensibilidade da massa e a razão tenacidade/extensibilidade puderam ser estimados pelo NDVI obtido no início do ciclo, mas não para todas as cultivares. As determinações de NDVI com sensor óptico GreenSeeker ativo em trigo, são eficientes para estimar em campo a produtividade de grãos e a qualidade da farinha, permitindo gerar modelos de estimativa destas variáveis separadamente para cada cultivar.

ABSTRACT Nitrogen fertilization is essential for wheat yield and quality but needs more accuracy, and the use of proximal optical sensors in the field can assist in this goal. This study aimed to verify if it is possible to use the normalized difference vegetation index (NDVI) obtained throughout the wheat growth phase to estimate the grain yield and the technological quality of the flour from cultivars submitted to nitrogen doses. The experiment was conducted at field conditions in Ponta Grossa, PR, Southern Brazil. The experimental design was randomized blocks in a 4 × 6 factorial scheme with four replicates. The cultivars Quartzo, Gralha Azul, Sinuelo, and Toruk, combined with six doses of N (0, 40, 80, 120, 160, and 200 kg ha-1 of N), were evaluated. The NDVI values were sensitive to both nitrogen doses and the different cultivars. There was a relationship between NDVI and grain yield, protein, and gluten concentration of flour. The NDVI estimated the gluten strength, stability, tenacity, extensibility of the mass, and tenacity/extensibility ratio of the flour obtained at the beginning of the cycle, but not for all cultivars. The determinations of NDVI with active optical sensor GreenSeeker in wheat are efficient to estimate the grain yield and the flour quality under field conditions, allowing to generate models for estimation of these variables separately for each cultivar.

ABSTRACT Biomass produced in agricultural areas stores energy that can be used, contributing to regional development. Among the widely cultivated agricultural species is oats, destined for the production of not only grains and forage, but also biomass. The objective of this study was to characterize oat biomass in terms of the potential for energy generation considering the genetic and cultivation environment variability. Four field experiments were conducted in the state of Paraná and one in the state of São Paulo, Brazil, with black oat (Avena strigosa) and white oat (Avena sativa) cultivars. At the milky grain stage, plants were collected to quantify the production of shoot biomass and its qualitative variables for energy production and energy potential. Biomass yield varied between cultivars and cultivation sites. The mean higher calorific value was 17.9 MJ Kg-1, varying more between cultivation sites than between cultivars, being inversely proportional to the ash content. The contents of carbon, fixed carbon, volatile materials and nitrogen in the biomass did not vary between oat cultivars. The power generation potential varied widely between cultivars and cultivation sites, from 1557 to 3091 KWh ha-1, influenced mainly by the biomass yield, which overlaps the effects of the variations found in biomass quality. We concluded that oats are a species with high potential for use as an energy product, and the selection of the most productive cultivars regionally is crucial. used development forage variability Paulo Brazil Avena strigosa sativa stage 179 17 9 17. Kg1, Kg1 Kg 1, 1 Kg-1 content carbon 155 309 ha1, ha1 ha ha-1 quality product crucial Kg- 15 30 ha- 3

RESUMO A biomassa produzida em áreas agrícolas armazena energia que pode ser aproveitada, contribuindo para o desenvolvimento regional. Entre as espécies agrícolas amplamente cultivadas está a aveia, destinada tanto para a produção de grãos e forragem quanto de biomassa. Este trabalho teve por objetivo caracterizar a biomassa da aveia quanto ao potencial de geração de energia considerando a variabilidade genética e de ambiente de cultivo. Para isso, foram conduzidos quatro experimentos a campo no estado do Paraná e um no estado de São Paulo, Brasil, com cultivares de aveia preta (Avena strigosa) e branca (Avena sativa). No estádio de grão leitoso as plantas foram coletadas para quantificar a produção de biomassa aérea e suas variáveis qualitativas para produção de energia e o potencial energético. A produtividade de biomassa variou entre as cultivares e locais de cultivo. A média do poder calorífico superior foi de 17,9 MJ Kg-1, variando mais entre os locais de cultivo que entre as cultivares, e sendo inversamente proporcional ao teor de cinzas. Os teores de carbono, carbono fixo, materiais voláteis e de nitrogênio na biomassa não variaram entre as aveias. O potencial de geração de energia variou amplamente entre cultivares e locais de cultivo, desde 1557 até 3091 KWh ha-1, influenciado principalmente pela produtividade de biomassa, que sobrepõe os efeitos das variações encontradas na qualidade da biomassa. Concluímos que a aveia é uma espécie com elevado potencial para uso como produto energético, sendo determinante a seleção das cultivares mais produtivas regionalmente. aproveitada regional isso Paulo Brasil Avena strigosa sativa. sativa . sativa) energético 179 17 9 17, Kg1, Kg1 Kg 1, 1 Kg-1 cinzas fixo aveias 155 309 ha1, ha1 ha ha-1 regionalmente Kg- 15 30 ha- 3

ABSTRACT The use of nitrification inhibitors (NIs; dicyandiamide - DCD) is an alternative to reduce oxidation of ammonium (NH4+-N) to nitrate (NO3–-N) in the soil, reducing NO3–-N losses from fertilization practices. Based on the hypothesis that DCD reduces conversion of NH4+-N to NO3–-N in tropical soils and inhibits ammonia oxidizing microorganisms (AOM) abundance, soils from the Piracicaba region, São Paulo, with different textures (sand, loam and clay) were incubated with ammonium sulphate (AS) and DCD. Contents of NH4+-N, NO3–-N, soil pH, and AOM abundance were quantified periodically. Ammonium sulphate increased AOM abundance in all soils, but AS+DCD presented AOM abundances similar to the control. During 90 days of incubation, the effectiveness of DCD in reducing NO3–-N production was 1.8, 86.4, and 145.6 mg kg–1, while the effectiveness of DCD in reducing AOM abundance was 1.2, 3.0 and 2.3 × 10–3 g soil–1 for sandy, loamy, and clayey soils, respectively. DCD effectiveness was greater in loamy and clayey soils due to the naturally low nitrification in sandy soils. Application of AS treated with DCD showed potential not only to reduce NO3–-N production in loamy and clayey soils, but also to decrease the soil nitrification rate. Overall, DCD was effective in reducing AOM abundance and conversion of NH4+-N to NO3–-N in loamy and clay soils evaluated here. The increase in clay content directly influences DCD effectiveness in reducing conversion of NH4+-N to NO3–-N.

RESUMO A Diabetes Mellitus Tipo 1 (DM1) é uma doença autoimune que afeta milhares de pessoas atualmente, com maior concentração de casos na adolescência. O tratamento implica alterações no estilo de vida que podem apresentar influência negativa sobre a qualidade do sono (QS) e qualidade de vida (QV). O propósito do estudo foi comparar a QS e QV entre adolescentes portadores e não portadores de DM1. Participaram do estudo 74 adolescentes divididos por grupos e sexo: GDM1-F (n=19), GDM1-M (n=18), GC-F (n=21) e GC-M (n=16). Os instrumentos utilizados foram o Índice de Qualidade do Sono de Pittsburgh e WHOQOL-bref. Para comparar os grupos foi utilizado Análise de Covariância, ajustada pela idade, com Post Hoc de Bonferroni. Os resultados sinalizam que os participantes do GDM1-F e GDM1-M, portadores de DM1, apresentaram maiores escores em todas as avaliações, com diferença significativa com o CG-F nas variáveis: QS global, Domínios Físico, Psicológico e Relações Sociais e QV total. Portanto, foi possível observar que os adolescentes portadores de DM1 apresentaram melhor avaliação da QS e QV em comparação as meninas sem DM1, independentemente da idade.

ABSTRACT Type 1 Diabetes Mellitus (DM1) is an autoimmune disease that affects thousands of people today, with a higher concentration of cases in adolescence. Treatment involves lifestyle changes that can have a negative influence on quality of sleep (QS) and quality of life (QL). The purpose of the study was to compare QS and QL among adolescents with and without DM1. Seventy-four adolescents participated in the study divided by groups and sex: GDM1-F (n=19), GDM1-M (n=18), GC-F (n=21) and GC-M (n=16). The instruments used were the Pittsburgh Sleep Quality Index and WHOQOL-bref. Age-adjusted Covariance Analysis with Bonferroni Post Hoc was used to compare the groups. The results show that the participants of GDM1-F and GDM1-M, with DM1, had higher scores in all evaluations, with significant difference with CG-F in the variables: global QS, Physical, Psychological and Social Relationships and total QL. Therefore, it was possible to observe that adolescents with DM1 had better QS and QL evaluations than girls without DM1, regardless of age.

Abstract The main destination of manure is the application to croplands near livestock farms as nutrient source to enhance crop production. The aim of this study was to define the dairy liquid manure (DLM) dose, complementary to the mineral fertilizer, for higher crops yield, in rotation black oat-maize-wheat-soybean, and to identify the soil chemical variables improved by the manure that most affect the yield, in long-term. The experiment was conducted from 2006 to 2015, in no-tillage system, at Paraná State, Brazil. The soil was a Latossolo Bruno Distrófico típico, clayey texture. The treatments consisted by doses of DLM (0, 60, 120 and 180 m3 ha-1 year-1), complementary to the mineral fertilizer (applied in the same amount for all DLM doses). Crops yield and soil chemical variables were evaluated at six depths (0-10; 10-20; 20-30; 30-40; 40-50 and 50-60 cm). The DLM application increased the yield of all crops, but not in all harvests. The DLM even applied at soil surface improved the soil chemical variables in deep layers, resulting in high positive correlation between yield and exchange bases, P, Zn and Mn contents, and high negative correlation with Ca/Mg ratio and potential acidity at depth 0-10 cm. The DLM dose, complementary to the mineral fertilization, that provided higher soybean and wheat yield was about 130 m3 ha-1 year-1, while for maize this dose was equal to or greater than 180 m3 ha-1 year-1. This effect was not attributed to a single chemical variable but the improvement of all chemical variables evaluated.

Abstract This study examined the effects of liming on soil acidity and base saturation (V) in Italian ryegrass (ryegrass) and silage maize production systems over the medium-term. A split-plot design with four replications was employed on Humic Hapludox. The plots consisted of four soil management methods: conventional tillage (CT), minimum tillage (MT), no-tillage (NT) and chiselled NT (CNT). Within the split plots, ryegrass was used as cover crop (CC), silage (S), and integrated crop-livestock (ICL) system. Following ryegrass phytomass the maize was sowed. Once the maize had been cut with a silage machine, soil samples were collected from the layers 0-5, 5-10, 10-15, 15-20 and 20-30 cm at 24 and 60 months after liming. The attributes pH, H+Al, exchangeable aluminium (Al3+), and V were evaluated. The highest pH and V values were observed in the 0-5 cm layer in NT. The CNT did not result in improvement of acidity conditions or V. The ryegrass as S and ICL decreased soil acidity from 10 cm layer. NT combined with ICL provided soil acidity improvements 60 months after liming. Therefore, the exploration of winter with Italian ryegrass may elicit greater benefits in deep soil layers than cover crops.

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.

ABSTRACT: Unchanged reference values of grain nutrient contents for corn have been used for over 20 years, despite yield increases, the development of new hybrids, and modifications to cropping systems, especially the establishment of in-season second crops and the wide adoption of no-tillage. This study measured macro- and micronutrient contents in corn grains from different regions, in the first (summer) and second (fall) crop, to update the reference values of estimated nutrient removal. A secondary objective was to determine whether there were correlations between grain nutrient contents and grain yields and densities. In this study, 175 corn grain samples of experiments on cultivar evaluation and 22 samples from soil management trials from five states (SP, PR, MG, MT, and MS) were used. Grain nutrient contents were ranked as follows: N > K > P > Mg > S (g kg−1) and Ca > Zn > Fe > Mn > B > Cu (mg kg−1). Content values for half of the nutrients analyzed were negatively correlated with yield and/or seed weight, whereas grain density was not correlated with nutrient contents. For the first crop of corn, the N, S, and Cu contents clearly decreased with increases in grain yield and seed weight, indicating a lower nutrient removal at higher yields. The great variability of results among environments makes it difficult to differentiate between the first and second crop of corn. The reference values currently in use overestimate the removal of N, P, K, Ca, Mg, S, and Zn grain contents, but underestimate Cu and B in corn. The results of this study can be used to update the reference values of nutrient contents of corn grains to better estimate nutrient removal from the soil.

Resumo: O objetivo deste trabalho foi avaliar a influência de manejos de azevém (Lolium multiflorum) sobre as propriedades físicas de um Latossolo Bruno e sobre a produção de milho e de azevém em sucessão ao milho. O experimento foi realizado em blocos ao acaso, com três tratamentos e três repetições, em que os tratamentos foram os diferentes manejos do azevém, em sistema plantio direto, para silagem, cobertura do solo e pastejo. Após nove anos de manejo, coletaram-se amostras a 0,00-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,30 m de profundidade do solo, para a determinação dos seguintes atributos: textura, carbono orgânico total, densidade, macroporosidade, microporosidade, porosidade total e resistência à penetração de raízes. O índice de estabilidade estrutural foi estimado a partir dos dados de textura e carbono orgânico total. A densidade máxima do solo e o ponto de murcha permanente também foram estimados a partir de funções de pedotransferência. As produtividades de massa de matéria seca do milho e do azevém foram determinadas a partir da colheita na parcela. O conteúdo de carbono orgânico total aumentou com o aumento da profundidade. Os manejos do azevém em plantio direto, em sucessão ao milho, não influenciam os atributos físicos do Latossolo Bruno e mantêm altas as produtividades de milho e de azevém.

Abstract: The objective of this work was to evaluate the influence of ryegrass (Lolium multiflorum) managements on the physical properties of a Haplohumox, and on the yields of corn and of ryegrass cultivated in succession to corn. The experiment was carried out in a randomized complete block design, with three treatments and three replicates, in which treatments were the different managements of ryegrass under no-tillage for silage, soil cover, and grazing. After nine years of management, samples were collected at 0.00-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30-m soil depths, to determine the following soil properties: texture, total organic carbon, soil bulk density, macroporosity, microporosity, total porosity, and resistance to root penetration. The index of structural stability was estimated from texture and total organic carbon data. Maximum soil bulk density and permanent wilting point were also estimated from pedotransfer functions. Corn and ryegrass dry matter yields were determined from plants harvested inside the plot area. Total organic carbon content increased as depth increased. The ryegrass managements in no-tillage system, in succession to corn, does not influence the soil physical properties of a Haplohumox, and maintains high corn and ryegrass yields.

Resumo Introdução: A infecção pelo vírus BK (BKV) em pacientes de transplante renal pode levar a disfunção do aloenxerto renal e perda do enxerto. A determinação precisa da carga viral do BKV é fundamental para prevenir a nefropatia associada ao BKV (BKVAN), mas o ponto de corte de melhor valor preditivo para BKVAN ainda é foco de debates. Objetivo: Avaliar o desempenho de um teste de qPCR comercial e outro desenvolvido internamente para detecção quantitativa de vírus BK em receptores de transplante renal. Métodos: O presente estudo prospectivo incluiu receptores de transplante renal de dois grandes hospitais universitários no Brasil. Os pacientes foram testados para infecção por BKV a cada três meses no primeiro ano pós-transplante com um teste comercial de reação em cadeia de polimerase quantitativa em tempo real (qPCR) e outro desenvolvido internamente. A presença de BKVAN foi confirmada com base na histopatologia. A área sob a curva para o qPCR plasmático foi determinada a partir da análise da característica de operação do receptor. Resultados: Um total de 200 pacientes foram incluídos. Cinquenta e oito por cento eram do sexo masculino, 19,5% tinham diabetes mellitus e 82% tiveram seus rins transplantados de doadores falecidos. Viremia de BKV foi detectada em 32,5% dos pacientes e oito (4%) foram diagnosticados com BKVAN. BKVAN foi associada a viremia de 4,1 log cópias/mL usando o kit comercial. O corte para o ensaio interno foi de 6,1 log cópias/mL. A linearidade entre o kit comercial e o ensaio interno foi R2 = 0,83. Conclusão: Nosso estudo demonstrou uma acentuada variabilidade na carga viral de BKV quando diferentes metodologias de qPCR foram utilizadas. O ensaio interno de qPCR mostrou-se clinicamente útil, além de ser uma opção menos onerosa em relação aos kits comerciais de qPCR. Há uma necessidade urgente de se definir padrões de BKV para a comunidade internacional.

Abstract Introduction: BK virus (BKV) infection in renal transplant patients may cause kidney allograft dysfunction and graft loss. Accurate determination of BKV viral load is critical to prevent BKV-associated nephropathy (BKVAN) but the cut-off that best predicts BKVAN remains controversial. Objective: To evaluate the performance of a commercial and an in-house qPCR test for quantitative detection of BK virus in kidney transplant recipients. Methods: This was a prospective study with kidney transplant recipients from two large university hospitals in Brazil. Patients were screened for BKV infection every 3 months in the first year post-transplant with a commercial and an in-house real time polymerase chain reaction (qPCR) test. BKVAN was confirmed based on histopathology. The area under the curve for plasma qPCR was determined from receiver operating characteristic analysis. Results: A total of 200 patients were enrolled. Fifty-eight percent were male, 19.5% had diabetes mellitus, and 82% had the kidney transplanted from a deceased donor. BKV viremia was detected in 32.5% and BKVAN was diagnosed in 8 patients (4%). BKVAN was associated with viremia of 4.1 log copies/mL, using a commercial kit. The cut-off for the in-house assay was 6.1 log copies/mL. The linearity between the commercial kit and the in-house assay was R2=0.83. Conclusion: Our study shows that marked variability occurs in BKV viral load when different qPCR methodologies are used. The in-house qPCR assay proved clinically useful, a cheaper option in comparison to commercial qPCR kits. There is an urgent need to make BKV standards available to the international community.

RESUMO A biomassa residual agrícola é uma importante fonte de energia e sua produção e qualidade varia com o manejo das lavouras. O objetivo deste estudo foi avaliar o efeito da distribuição de plantas e da adubação nitrogenada sobre o potencial de produção de energia da biomassa do milho cultivado sob sistema de plantio direto. O experimento de campo foi instalado no sudeste do Brasil, com cinco doses de nitrogênio (0, 60, 120, 180 e 240 kg ha-1) e dois espaçamentos entrelinhas (0,4 e 0,8 m). Foram realizadas avaliações de produtividade de grãos, produtividade de biomassa residual e potencial de bioenergia em diferentes partes da planta (grão, colmo + folha, palha da espiga e sabugo). A variação no espaçamento não alterou o rendimento de grãos. A produtividade de folhas + palha de espiga foi maior em 0,8 m do que 0,4 m de espaçamento. A aplicação de nitrogênio resultou no aumento do rendimento de grãos e da produtividade de biomassa. O nitrogênio influência o potencial da bioenergia ao aumentar a biomassa e o poder calorífico. Com a dose de 226 kg ha-1 de nitrogênio, taxa máxima para o rendimento de grãos, e considerando apenas o uso de palha da espiga e sabugo, é possível gerar 2712 kWh ha-1 de bioenergia.

ABSTRACT Agricultural residual biomass is an important source of energy, and its production and quality vary according to the crop management. This study aimed to assess the effects of plant distribution and nitrogen fertilization on the energy production potential of the biomass of maize cultivated under no tillage. The field experiment was installed in southeast Brazil using five nitrogen rates (0, 60, 120, 180, and 240 kg ha-1) and two inter-row spacings (0.4 and 0.8 m). Grain yield, residual biomass productivity, and bioenergy potential in different parts of the plant (grain, stalk+leaf, husk, and cob) were assessed. No change in grain yield was observed using narrow row spacing. Stalk+leaf and husk productivity was higher using 0.8 m than using 0.4 m of inter-row spacing. Nitrogen application resulted in increased grain yield and biomass productivity. Nitrogen influences the bioenergy potential by increasing the biomass and calorific value. Application of the maximum nitrogen fertilization rate is recommended for grain yield considering the use of only the husk and cob can generate 2712 kWh ha-1 of bioenergy.

RESUMO A correção da acidez do solo no sistema plantio direto (SPD) é feita por meio da aplicação de calcário na superfície sem incorporação. Com a hipótese de que a fonte e granulometria dos corretivos interferem na velocidade de reação no solo em curto prazo e na resposta das culturas à calagem na superfície em SPD, foram realizados dois experimentos, sendo um em Latossolo Vermelho Distrófico textura muito argilosa e outro em Neossolo Litólico Húmico textura franco-arenosa, no período de 2010 a 2012. O delineamento empregado, em cada experimento, foi em blocos completos ao acaso, no esquema fatorial 2 × 2 × 4, com três repetições. Os tratamentos foram constituídos de duas fontes de calcário, calcítico (25-50 g kg-1 MgO) e dolomítico (160-180 g kg-1 MgO), duas faixas de poder relativo de neutralização total (PRNT), faixa B (PRNT de 60 a 75 %) e faixa D (PRNT>90 %), e quatro doses de calcário na superfície, sendo um tratamento-controle sem calagem e três doses estimadas para elevar a saturação por bases do solo (0,00-0,20 m), a 50, 70 e 90 %. Nos dois experimentos, o calcário foi aplicado a lanço sobre a superfície do solo, em agosto de 2010. Realizaram-se dois cultivos em 2010/11 e 2011/12, com milho e soja, no Latossolo Vermelho Distrófico, e soja e milho, no Neossolo Litólico Húmico, respectivamente. A aplicação superficial de calcário nos dois solos, após 12 meses, proporcionou redução da acidez na camada de 0,00-0,05 m e, em menor grau, na de 0,05-0,10 m. A amenização da acidez nas camadas da superfície foi mais acentuada com o emprego de doses mais elevadas de calcário calcítico e de corretivo com granulometria mais fina. A calagem superficial aumentou as concentrações de Ca-foliar com a utilização de calcário calcítico e de Mg-foliar com o uso de calcário dolomítico, e reduziu os teores foliares de Mn e Zn, independentemente da fonte de calcário, nas culturas de milho e soja. As produtividades de grãos de milho e soja no Latossolo Vermelho Distrófico e Neossolo Litólico Húmico aumentaram com as doses de calcário, mas não foram influenciadas pelas fontes e faixas de PRNT dos corretivos. A calagem superficial é uma prática efetiva e importante para maximizar a produtividade de grãos das culturas em SPD, independentemente do teor de Mg e da granulometria dos corretivos.

ABSTRACT To reduce acidity in no-till systems, lime is broadcast on the soil surface without incorporation. Two experiments were carried out, one in a clayey Latossolo Vermelho Distrófico (Rhodic Hapludox) and another in a sandy loam Neossolo Litólico Húmico (Lithic Hapludoll), to test the hypothesis that the source and particle size of lime influence soil reaction in the short term, and crop response to surface liming under a no-till system. A randomized complete block design was used in a 2 × 2 × 4 factorial arrangement with three replications for each experiment. The treatments consisted of two sources of lime, calcitic (25-50 g kg-1 MgO) and dolomitic (160-180 g kg-1 MgO); two ranges of effective calcium carbonate equivalent (ECCE) of lime material, range B (ECCE 60-75 %) and range D (ECCE>90 %); and four rates of lime on the surface, one control treatment without lime and three rates estimated to raise the base saturation of the topsoil (0.00-0.20 m) to 50, 70, and 90 %. In both experiments, lime was surface applied in August 2010. During the spring-summer season in 2010/11 and 2011/12, corn and soybean were grown on the Latossolo Vermelho Distrófico, and soybean and corn on the Neossolo Litólico Húmico, respectively. Surface application of lime in both soils after 12 months led to reduction in soil acidity mainly in the 0.00-0.05 m layer and, to a lesser extent, in the 0.05-0.10 m layer. Calcitic lime at higher rates and lime composed of finer particles showed a greater reduction in acidity in the soil surface layers. Surface liming increased the Ca-leaf content, especially with the use of calcitic lime, and Mg-leaf content, mainly with the use of dolomitic lime. It also reduced Mn and Zn contents in the leaves, regardless of the source of lime, in the corn and soybean crops. Grain yields of corn and soybean in both the clayey Latossolo Vermelho Distrófico and the sandy loam Neossolo Litólico Húmico increased with increasing lime rates, but were not affected by the sources and ECCE ranges of lime. The surface application of lime is an effective and important practice to maximize crop grain yields under no-till systems, regardless of magnesium content and particle size of the lime.

Os efeitos da calagem e da gessagem são amplamente conhecidos na literatura, mas a sua magnitude em relação aos efeitos no perfil do solo é dependente do tempo após a aplicação desses insumos. Dessa maneira, o objetivo deste trabalho foi avaliar em longo prazo a aplicação conjunta de gesso e calcário nos atributos químicos de um solo em rotação de culturas, no sistema de plantio direto. O experimento foi conduzido em uma propriedade rural no município de Jaguariaíva, PR, em um Latossolo Vermelho-Amarelo distrófico típico, de textura areia franca, durante os anos de 2002 a 2008. O experimento foi conduzido em blocos ao acaso sob esquema fatorial com 10 tratamentos, sendo cinco doses de gesso agrícola (0; 1,5; 3,0; 6,0; e 12,0 Mg ha-1) e duas doses de calcário (0 e 3,42 Mg ha-1), com três repetições. Foram avaliadas no decorrer dos 72 meses as espécies aveia-preta-comum (2004, 2006 e 2007), milho (2005/2006), trigo (2003) e soja (2003/2004, 2004/2005, 2006/2007 e 2007/2008). Realizaram-se amostragem e análise de solo nos anos de 2005 e 2008 até 100 cm de profundidade e de tecido foliar da soja, na safra de 2007/2008. A aplicação de calcário corrigiu o pH, aumentou a concentração de Ca e Mg e diminuiu o Al, nas camadas superficiais do solo. O gesso proporcionou incremento no pH e nas concentrações de Ca e S em profundidade, lixiviou Mg e não lixiviou o K. A calagem elevou a produtividade do milho, da soja (uma das quatro safras avaliadas) e da aveia- preta. O gesso favoreceu a produtividade do milho e do trigo e a da soja, somente quando houve deficiência hídrica. Quando, no entanto, não houve deficiência hídrica, altas doses de gesso prejudicaram a produtividade de grãos de soja por indução de deficiência de Mg.

The effects of lime and gypsum are widely discussed in the literature, but their magnitude in relation to effects in the soil profile is dependent on the time since application of these inputs. Thus, the aim of this study is to evaluate the effect of long-term application of gypsum and lime on chemical properties of a soil in crop rotation in a no-till system. The experiment was carried out in Jaguariaíva, Paraná state, Brazil, in a sandy loam Latossolo Vermelho-Amarelo distrófico típico (Oxisol), from 2002 to 2008. A randomized block experimental design was used in a factorial arrangement with ten treatments, consisting of five doses of gypsum (0, 1.5, 3.0, 6.0 and 12.0 Mg ha-1) and two doses of lime (0 and 3.42 Mg ha-1) with three replications. The following crops were evaluated over a period of 72 months: black oat (2004, 2006 and 2007), maize (2005/2006), wheat (2003) and soybean (2003/2004, 2004/2005, 2006/2007 and 2007/2008). Soil sampling and soil analysis was carried out in 2005 and 2008 up to a depth of 100 cm, and leaf tissue analysis of the soybean crop in 2007/2008. Liming amended pH, increased the concentration of Ca and Mg and decreased Al in the surface layers of the soil. Gypsum brought about an increase in pH and in the concentrations of Ca and S at greater depth, leached Mg and did not leach K. Liming increased the yield of maize, soybean (one of the four crop seasons evaluated) and black oat. Gypsum favored yield in corn and wheat, and in soybean only when there was water deficit. However, when there was no water stress, high doses of gypsum decreased soybean yield through inducing Mg deficiency.