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This study aimed to evaluate the effects of different sowing depths and light intensities on the emergence and development of the monocot weed species, Urochloa decumbens and Cenchrus echinatus, under field conditions. Each species constituted an experiment, and the experimental design was completely randomized with four replicates. The treatments were arranged in a 6 x 4 factorial scheme, with six sowing depths (0.5, 1.0, 2.0, 4.0, 8.0, and 12.0 cm) associated with four solar radiation intensities (100%, 70%, 50%, and 30%) obtained through the use of shading screens. Seedling emergence capacity was evaluated daily to obtain the emergence percentage and speed index. Plant height, floral induction time, and plant dry matter at flowering were measured. Even when subjected to different solar radiation intensities, U. decumbens and C. echinatus seedlings emerged at all the sowing depths. Sowing between 2.0- and 4.0-cm depths favored the emergence of seedlings of U. decumbens and C. echinatus. However, sowing at 12-cm depth reduced the emergence of both species regardless of the solar radiation intensity. Urichloa decumbens plants grown under conditions of greater shading showed the lowest values of height and dry matter accumulation during flowering. High levels of shading facilitated only the etiolation of C. echinatus plants. Increased shading flowering time in both species compared to full sunlight.

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The objective of this study was to evaluate the spatial variability of structural characteristics of deferred pastures of Brachiaria decumbens cv. Basilisk (signal grass) subjected to associations of sward heights (10, 20, 30, and 40 cm) at the beginning of deferment and grazing periods (1, 28, 56, 85, and 113 days). The experiment was arranged in a split-plot and completely randomized-block design with two replicates. Pastures remained deferred from March to June 2010. From June to the beginning of October 2010, deferred pastures were utilized by steers under continuous grazing and at a fixed initial stocking rate of 3.5 AU ha-1. At the beginning of the deferment, the coefficient of variation (CV) for pasture height was reduced linearly with the pasture height. During the grazing period, in the winter, the CV for pasture height was not influenced by initial pasture height; however, it responded quadratically to the grazing period, with a maximum value of 36.4% at 71 days of the period of utilization. The CV for tiller height was reduced linearly with pasture height at the beginning of deferment but increased linearly along with the grazing period. The initial pasture height did not change the CV of the falling index. However, the latter was quadratically influenced by the grazing period, with a maximum value of 59.5% at 67 days of the utilization period. Signal grass pastures deferred at a lower height have a higher spatial variability of the vegetation. In the grazing period, there are changes in the spatial variability of the vegetation of the deferred signal grass.

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Competition with invasive grasses is one of the most important drivers of tree planting failures, especially in tropical forests. A widely disseminated weeding approach has been glyphosate spraying, the most used herbicide globally in forestry and ecosystem restoration. However, glyphosate use in restoration is highly controversial and requires further studies to elucidate its effects on restoration processes and the environment. We evaluated the use of glyphosate in riparian forest restoration and its impacts on tree planting costs, weed control efficiency, planted seedling performance, herbaceous and woody species regeneration, soil bacteria, and environmental contamination, using mowing treatments as a reference and based on a controlled experiment established in the Brazilian Atlantic Forest. Glyphosate spraying reduced by one-half and one-third the accumulated aboveground biomass of, respectively, weeds in general and of the invasive grass Urochloa decumbens compared to mowing treatments, and it reduced the cost by half. The performance of planted tree seedlings was markedly favored by glyphosate spraying compared to mowing treatments, as expressed by improved seedling height (~twice higher), crown area (~5× higher), and basal area (~5× higher); the regeneration of both native woody and ruderal herbaceous plants were also enhanced. Neither glyphosate nor its metabolite Aminomethylphosphonic acid (AMPA) residues were detected in either water runoff or soil samples, but they were found at relatively high concentrations in the runoff sediments (from 1.32 to 24.75 mg/kg for glyphosate and from 1.75 to 76.13 mg/kg for AMPA). Soil bacteria communities differed before and after glyphosate spraying in comparison to mowing plots (without glyphosate). Glyphosate spraying was far more cost effective than mowing for controlling U. decumbens and greatly improved the performance of planted tree seedlings and natural regeneration, while not leaving residues in soil and water. However, the changes in the structure of bacterial communities and high concentration of glyphosate and AMPA residues in runoff sediments highlight the need for caution when using this herbicide in riparian buffers. We present alternatives for reducing glyphosate use and minimizing its risks in tree planting initiatives.

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This research evaluated the effects of coffee cultivation with two different water regimes associated or not with liming and the presence/absence of brachiaria as intercrop on the activities of the soil enzymes ß-glucosidase, arylsulfatase and acid phosphatase. The study was carried out at the experimental farm of Embrapa Cerrados, using the cultivar IAC 144 (Coffea arabica L.), under a clayey dystrophic Cerrado Oxisol. Two water regimes (WR) were considered, WR1 with irrigation shifts throughout the year and WR3 with controlled water stress, for about 70 days, in the dry season. In each water regime, effects of lime application (with/without) and the presence/absence of brachiaria cultivated between the lines of coffee plants were evaluated. The activities of the enzymes ß-glucosidase, arylsulfatase and acid phosphatase were evaluated during the rainy and dry seasons. Liming and intercropped brachiaria positively affected the activities of the three enzymes assessed in this study at varying degrees, depending on season and/or the WR. Our findings evidenced that intercropped brachiaria in coffee rows was the factor that most positively impacted soil enzymes activities.

O objetivo desse trabalho foi avaliar os efeitos do cultivo do café sobre a atividade das enzimas do solo ß-glicosidase, arilsulfatase e fosfatase ácida em função de dois diferentes regimes hídricos associados ou não à calagem e ao cultivo de braquiária nas entrelinhas. Esse estudo foi realizado em um experimento conduzido no campo experimental do Centro de Pesquisa Agropecuária dos Cerrados, utilizando a cultivar IAC 144 (Coffea arabica L.), sob um Latossolo Vermelho distrófico argiloso. Foram considerados dois regimes hídricos (RH), RH1 com irrigação plena em turnos de rega ao longo do ano e RH3 com estresse hídrico controlado, por cerca de 70 dias, na época seca. Em cada regime hídrico foram avaliadas a aplicação ou não de calcário em cobertura e a presença ou ausência de braquiária cultivada nas entrelinhas das plantas do cafezal. As atividades das enzimas ß-glicosidase, arilsulfatase e fosfatase ácida foram avaliadas durante as estações chuvosa e seca. A calagem e a presença de braquiária nas entrelinhas tiveram efeito positivo sobre a atividade das três enzimas avaliadas nesse estudo, em graus variáveis, dependendo da época de coleta das amostras e/ou do RH. Nossos resultados evidenciam que a braquiária nas entrelinhas do café foi o fator de maior impacto positivo sobre a atividade enzimática do solo.

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High propagule availability compared to native species is often critical to invasion success, but it is unclear if this has contributed to invasions by African grasses in Neotropical savannas. We compared patterns of occurrence in the vegetation, seed rain and seed bank among African and native grasses in Cerrado sites in southeastern Brazil. In grasslands and savannas, we obtained the abundance of grasses in the vegetation, in the seed rain (monthly for one year) and in the seed bank (rainy and dry season), and assessed seed limitation and relationships among compartments. Invasive grasses showed low abundance in all compartments and high seed limitation in grasslands, where the seed bank and seed rain were dominated by small-seeded native grasses, but were at least as abundant as the natives in the seed bank and seed rain in savannas, mostly due to high abundance of Melinis minutiflora at these compartments. Native grasses dispersal occurred in the rainy season, whereas invasive grass dispersal occurred from mid rainy to mid dry season (Urochloa decumbens) and in the dry season (M. minutiflora). Melinis minutiflora showed a more persistent seed bank than U. decumbens and natives in savannas. Abundance of invasive and most of the native grasses in the vegetation was positively related to their abundance in the seed rain. Differences in seed production, the timing of seed dispersal and seed bank persistence compared to native grasses seem to favour invasive African grasses in the Cerrado, but this role may differ between grasslands and savannas.

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Cadmium (Cd) is a very toxic heavy metal occurring in places with anthropogenic activities, making it one of the most important environmental pollutants. Phytoremediation plants are used for recovery of metal-contaminated soils by their ability to absorb and tolerate high concentrations of heavy metals. This paper aims to evaluate the potential of grasses in phytolith production in soils contaminated with Cd. The experiments, separated by soil types (Typic Quartzipsamment, Xanthic Hapludox and Rhodic Hapludox), were conducted in a completely randomized design with a distribution of treatments in a 3 × 4 factorial scheme with three replications. The factors were three grasses (Urochloa decumbens, Urochloa brizantha and Megathyrsus maximus) and four concentrations of Cd applied in soils (0, 2, 4 and 12 mg kg-1). Grass growth decreased and increased Cd concentration in shoots of grasses with the increased Cd rates in soils. The toxic effect of Cd resulted in production and Cd occlusion in phytoliths produced in shoots of the grasses. Grasses showed potential for phytolith production, independent of soil type, providing phytoextraction of Cd in phytoliths. Megathyrsus maximus was the grass with the highest tolerance to Cd, evidenced by higher production and Cd capture in phytoliths for the evaluated soils. Phytolith production by grasses in Cd-contaminated soils is related to genetic and physiological differences of the evaluated grasses and Cd availability in soils.

RESUMO

Grandes quantidades de resíduos da agroindústria avícola são produzidas em áreas próximas aos criadouros, e muitas vezes esses resíduos são usados como fonte de adubação em pastagens, podendo alterar os atributos químicos e físicos do solo. O presente estudo objetivou avaliar os efeitos de aplicações de doses contínuas ao longo do tempo (até oito anos) de cama de peru nos atributos químicos e físicos de um Latossolo Vermelho distroférrico sob pastejo rotacionado. A área experimental foi dividida em 16 piquetes de 0,5 ha cada , e cultivada com Uroclhoa decumbens em sistema de pastejo rotativo. Os tratamentos foram dados por doses acumuladas de cama de peru, com aplicações anuais desde 2008 até o ano de 2015, sendo os seguintes: controle, 35,29; 51,79 e 66,24 Mg ha-1. O uso continuado de cama de peru por pelo menos 5 anos (35,29 Mg ha-1) promoveu incrementos nos teores de fósforo, potássio e a saturação por bases, além de reduzir a acidez e a saturação por alumínio. Alterações na matéria orgânica do solo, no entanto, foram encontradas somente após até 8 anos (66,24 Mg ha-1) de uso contínuo de cama de peru.Houve pouco efeito da utilização de cama de peru na relação Ca:Mg e também nos atributos físicos do solo, exceto pela macroporosidade na camada superficial, que foi maior nas doses intermediárias de cama de peru.(AU)

Large amounts of poultry agroindustry residues are produced in areas near the breeding grounds, and often these residues are used as a source of fertilization in pastures, which may affect the chemical and physical attributes of the soil. The aim of this study was to evaluate the effects of continuous application over time (up to eight years) of turkey manure on the chemical and physical attributes of an Oxisol under rotational grazing. The experimental area was divided into 16 plots of 0.5 ha each, and cultivated with Uroclhoa decumbens in rotational grazing system. Treatments were given by accumulated doses of turkey manure, with annual applications from 2008 to 2015, as follows: control, 35.29; 51.79 and 66.24 Mg ha-1. Continued use of turkey manure for at least 5 years (35.29 Mg ha-1) promoted increases in phosphorus, potassium and base saturation, as well as reducing acidity and aluminum saturation. Changes in soil organic matter, however, were found only after 8 years (66.24 Mg ha-1) of continuous use of turkey manure. There was little effect of turkey manure use on Ca:Mg ratio and also on soil physical attributes, except for macroporosity in the superficial layer, which was higher in intermediate doses of turkey manure.(AU)

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Grandes quantidades de resíduos da agroindústria avícola são produzidas em áreas próximas aos criadouros, e muitas vezes esses resíduos são usados como fonte de adubação em pastagens, podendo alterar os atributos químicos e físicos do solo. O presente estudo objetivou avaliar os efeitos de aplicações de doses contínuas ao longo do tempo (até oito anos) de cama de peru nos atributos químicos e físicos de um Latossolo Vermelho distroférrico sob pastejo rotacionado. A área experimental foi dividida em 16 piquetes de 0,5 ha cada , e cultivada com Uroclhoa decumbens em sistema de pastejo rotativo. Os tratamentos foram dados por doses acumuladas de cama de peru, com aplicações anuais desde 2008 até o ano de 2015, sendo os seguintes: controle, 35,29; 51,79 e 66,24 Mg ha-1. O uso continuado de cama de peru por pelo menos 5 anos (35,29 Mg ha-1) promoveu incrementos nos teores de fósforo, potássio e a saturação por bases, além de reduzir a acidez e a saturação por alumínio. Alterações na matéria orgânica do solo, no entanto, foram encontradas somente após até 8 anos (66,24 Mg ha-1) de uso contínuo de cama de peru.Houve pouco efeito da utilização de cama de peru na relação Ca:Mg e também nos atributos físicos do solo, exceto pela macroporosidade na camada superficial, que foi maior nas doses intermediárias de cama de peru.

Large amounts of poultry agroindustry residues are produced in areas near the breeding grounds, and often these residues are used as a source of fertilization in pastures, which may affect the chemical and physical attributes of the soil. The aim of this study was to evaluate the effects of continuous application over time (up to eight years) of turkey manure on the chemical and physical attributes of an Oxisol under rotational grazing. The experimental area was divided into 16 plots of 0.5 ha each, and cultivated with Uroclhoa decumbens in rotational grazing system. Treatments were given by accumulated doses of turkey manure, with annual applications from 2008 to 2015, as follows: control, 35.29; 51.79 and 66.24 Mg ha-1. Continued use of turkey manure for at least 5 years (35.29 Mg ha-1) promoted increases in phosphorus, potassium and base saturation, as well as reducing acidity and aluminum saturation. Changes in soil organic matter, however, were found only after 8 years (66.24 Mg ha-1) of continuous use of turkey manure. There was little effect of turkey manure use on Ca:Mg ratio and also on soil physical attributes, except for macroporosity in the superficial layer, which was higher in intermediate doses of turkey manure.

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The effect of four nitrogen levels (0, 40, 80 and 120kg N ha-1), applied before deferment on the beef cattle production and structural variables on Urochloa decumbens (signal grass) were assessed from January to October 2012 and from January to September 2013. A randomized block design with three replicates was adopted, in an arrangement of repeated measures in time (grazing period). An interaction effect between nitrogen level and grazing period was observed on extended-plant height and herbage mass. As the nitrogen levels were increased, extended-plant height, herbage mass, total herbage allowance, and efficiency of conversion of fertilizer into herbage were increased. Throughout the grazing period, pasture height, extended-plant height, percentage of leaves, herbage and morphological components allowance, and percentages of leaves and stems in the herbage apparently selected by the animal decreased. Nitrogen levels had no effect on average daily gain or gain per area in the first year. A fixed deferment period with increasing levels of nitrogen fertilization on signal grass pastures does not influence the average daily gain per animal, reduces the efficiency of the nitrogen fertilizer and negatively changes the structural characteristics of the pasture.(AU)

Foi avaliado o efeito de quatro doses de nitrogênio (0, 40, 80 e 120kg N ha -1 ), aplicadas antes do diferimento, sobre o desempenho de bovinos e as características estruturais de Urochloa decumbens (capim-braquiária), de janeiro a outubro de 2012 e de janeiro a setembro de 2013. Um delineamento de blocos ao acaso foi utilizado em arranjo de medidas repetidas no tempo (período de pastejo). Foi observada interação entre doses de nitrogênio e período de pastejo na altura da planta estendida e na massa de forragem. As doses de nitrogênio incrementaram a altura da planta estendida, a massa de forragem, a oferta de forragem e a eficiência de conversão do nitrogênio em forragem. No decorrer do período de pastejo, a altura do pasto, a altura da planta estendida, a porcentagem de lâminas foliares, a oferta de forragem e dos seus componentes morfológicos e a porcentagem de lâminas e colmos da forragem aparentemente selecionada pelos animais diminuíram. As doses de nitrogênio não exerceram efeito sobre o ganho diário e o ganho diário por área no primeiro ano. O período de diferimento fixo com aumento das doses de nitrogênio em pastos de capim-braquiária não influencia o ganho diário por animal, reduz a eficiência da adubação nitrogenada e afeta negativamente a estrutura do pasto.(AU)

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RESUMO

The effect of four nitrogen levels (0, 40, 80 and 120kg N ha-1), applied before deferment on the beef cattle production and structural variables on Urochloa decumbens (signal grass) were assessed from January to October 2012 and from January to September 2013. A randomized block design with three replicates was adopted, in an arrangement of repeated measures in time (grazing period). An interaction effect between nitrogen level and grazing period was observed on extended-plant height and herbage mass. As the nitrogen levels were increased, extended-plant height, herbage mass, total herbage allowance, and efficiency of conversion of fertilizer into herbage were increased. Throughout the grazing period, pasture height, extended-plant height, percentage of leaves, herbage and morphological components allowance, and percentages of leaves and stems in the herbage apparently selected by the animal decreased. Nitrogen levels had no effect on average daily gain or gain per area in the first year. A fixed deferment period with increasing levels of nitrogen fertilization on signal grass pastures does not influence the average daily gain per animal, reduces the efficiency of the nitrogen fertilizer and negatively changes the structural characteristics of the pasture.(AU)

Foi avaliado o efeito de quatro doses de nitrogênio (0, 40, 80 e 120kg N ha -1 ), aplicadas antes do diferimento, sobre o desempenho de bovinos e as características estruturais de Urochloa decumbens (capim-braquiária), de janeiro a outubro de 2012 e de janeiro a setembro de 2013. Um delineamento de blocos ao acaso foi utilizado em arranjo de medidas repetidas no tempo (período de pastejo). Foi observada interação entre doses de nitrogênio e período de pastejo na altura da planta estendida e na massa de forragem. As doses de nitrogênio incrementaram a altura da planta estendida, a massa de forragem, a oferta de forragem e a eficiência de conversão do nitrogênio em forragem. No decorrer do período de pastejo, a altura do pasto, a altura da planta estendida, a porcentagem de lâminas foliares, a oferta de forragem e dos seus componentes morfológicos e a porcentagem de lâminas e colmos da forragem aparentemente selecionada pelos animais diminuíram. As doses de nitrogênio não exerceram efeito sobre o ganho diário e o ganho diário por área no primeiro ano. O período de diferimento fixo com aumento das doses de nitrogênio em pastos de capim-braquiária não influencia o ganho diário por animal, reduz a eficiência da adubação nitrogenada e afeta negativamente a estrutura do pasto.(AU)

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This study aimed to evaluate the effect of different doses of nitrogen fertilization on the morphogenic, structural, productive and chemical composition of Urochloa decumbens (Stapf) R. D. Webster cv. Basilisk in a silvopastoral system with eucalyptus. The experimental treatments consisted of pastures of Basilisk cultivar, fertilized with 0, 100, 200, 300 and 400 kg ha-1 year-1 of N, and intercropped with eucalyptus, clone GG 100 (Eucalyptus grandis x E. urophylla). The experimental arrangement followed a randomized block design with four replicates. The evaluated characteristics were: foliar appearance rate, phyllochron, leaf length, leaf elongation rate, leaf life span, foliar senescence rate, number of green leaves per tiller, number of senescent leaves per tiller, daily dry matter accumulation, dry matter production, crude protein, and neutral detergent fiber. In the conditions of the established silvopastoral system, nitrogen fertilization did not influence (p > 0.05) the morphogenic and structural characteristics of Basilisk cultivar, except for height (p 0.01) and leaf: stem ratio (p = 0.02). The nitrogen fertilization of the Brachiaria grass with eucalyptus in the proposed structural arrangement does not modify (p > 0.05) the morphogenic characteristics. However, in ration to dry matter production, doses of up to 400 kg of N ha-1 are recommended.(AU)

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RESUMO

This study aimed to evaluate the effect of different doses of nitrogen fertilization on the morphogenic, structural, productive and chemical composition of Urochloa decumbens (Stapf) R. D. Webster cv. Basilisk in a silvopastoral system with eucalyptus. The experimental treatments consisted of pastures of Basilisk cultivar, fertilized with 0, 100, 200, 300 and 400 kg ha-1 year-1 of N, and intercropped with eucalyptus, clone GG 100 (Eucalyptus grandis x E. urophylla). The experimental arrangement followed a randomized block design with four replicates. The evaluated characteristics were: foliar appearance rate, phyllochron, leaf length, leaf elongation rate, leaf life span, foliar senescence rate, number of green leaves per tiller, number of senescent leaves per tiller, daily dry matter accumulation, dry matter production, crude protein, and neutral detergent fiber. In the conditions of the established silvopastoral system, nitrogen fertilization did not influence (p > 0.05) the morphogenic and structural characteristics of Basilisk cultivar, except for height (p 0.01) and leaf: stem ratio (p = 0.02). The nitrogen fertilization of the Brachiaria grass with eucalyptus in the proposed structural arrangement does not modify (p > 0.05) the morphogenic characteristics. However, in ration to dry matter production, doses of up to 400 kg of N ha-1 are recommended.

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Several strategies have been used to improve soil fertility using integrated crop-livestock (ICL) systems, and the harvest of the accompanying crop used for silage may have several benefits to the soil depending on the quantity and quality of the remaining litter, providing dry matter (DM) for no-tillage systems and nutrient mineralization for the subsequent crop. The objective of this study is to evaluate the rate of decomposition of macro- and micronutrients of the DM of litter produced in ICL systems at different harvest heights in one year. The study was developed at the Experimental Farm of UNESP in Selvíria, Mato Grosso do Sul, Brazil, in the dry season. The study included five replications in plots of 200 m2 and was arranged in a completely randomized block design. The following treatments were analyzed: control sample-degraded pasture of signal grass; Marandu grass-pasture renewal from signal grass to Marandu grass; succession 45-planting of sorghum (forage sorghum cv. Volumax) and crop harvest at the height of 45 cm for silage followed by planting of Marandu grass; simultaneous seeding of Marandu grass and sorghum, and crop harvesting for silage at the height of 15 cm (Marandu + sorghum 15) and 45 cm (Marandu + sorghum 45) from the soil surface. After crop harvesting, proportional amounts of green mass remaining from each unit were collected, transferred to nylon bags, and placed in direct contact with the soil of the respective experimental unit. Each bag was opened every 30 days after closure for up to 270 days. In each bag, the DM, and macro- and micronutrients were analyzed, and the percentage of remaining material, daily decomposition rate, and half-life were calculated. The litter of the Marandu + sorghum 45 treatment contained the highest DM, decomposition rate, and nutrient content...(AU)

Tem sido frequente a adoção de estratégias que visem melhorias na fertilidade do solo em sistemas de integração lavoura-pecuária (ILP) e a altura de colheita para ensilagem da cultura acompanhante, pode direcionar diversos benefícios ao solo pela quantidade e qualidade da liteira remanescente, proporcionando massa seca (MS) para o plantio direto e mineralização de nutrientes para a cultura subsequente. Objetivou-se com esse trabalho estudar a dinâmica de decomposição, ao longo de um ano, da MS, macro e micronutrientes de liteiras oriundas de sistemas de ILP com diferentes alturas de colheita. O experimento foi desenvolvido em campo na Fazenda Experimental da UNESP em Selvíria, MS, na condição de sequeiro. O delineamento adotado foi em blocos completos casualizados, com cinco repetições em parcelas de 200 m2. Os tratamentos corresponderam a Testemunha - pastagem degradada de capim-decumbens; Marandu - renovação da pastagem de capim-decumbens para capim-marandu; Solteiro 45 - capim-marandu semeado em sucessão ao sorgo (Sorgo forrageiro cv. Volumax) solteiro que foi colhido a 45 cm de altura para silagem e; capim-marandu semeado simultaneamente com o sorgo que foi colhido para silagem a 15 (Simultâneo 15) e 45 cm (Simultâneo 45) de altura em relação à superfície do solo. Após a colheita da cultura foram amostradas quantidades proporcionais de massa verde remanescentes de cada unidade experimental que foram acondicionadas dentro de sacos de nylon depositados em contato direto com o solo da respectiva unidade experimental. A abertura de cada saco ocorreu a cada 30 dias até 270 dias após o fechamento. Para cada abertura foram analisados a MS, macro e micronutrientes e calculado o percentual de material remanescente, taxa de decomposição diária e o tempo de meia vida. O tratamento Sucessão 45 foi o que proporcionou a maior massa de liteira, taxa de decomposição e maiores teores de nutrientes na MS...(AU)

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The present study evaluated the survival and injuries of Deois flavopicta (Hemiptera: Cercopidae) in pastures of Urochloa (Syn. Brachiaria) decumbens and U. brizantha, submitted to seed treatment with fipronil (Amulet®) and thiamethoxam (Cruiser 350 FS®), and dry mass yield. The experiment, carried out at the APTA Experimental Unity, São José do Rio Preto, SP, Brazil, was designed in randomly blocks, with six treatments (factorial 2x3) and four replications. Sowing was manual, with 12.0 kg ha-1 seeds. Twenty adults were released on the plot, in a 40x40x70 cm cage, forty-nine days after sowing. The insects were sampled every two days during twelve days, without replacement of dead insects. Injuries caused by the spittlebug were evaluated by a rating scale and by productivity (dry mass yield). Data were analyzed by F-test and means compared by Tukey's test (p≤0.05). The survival of adults was higher in the U. decumbens pasture than in the U. brizantha pasture. Results show that seed treatment with thiamethoxam reduced the survival of D. flavopicta in pasture formation, but did not influence the injuries caused by insect and the dry mass yield of forage species.(AU)

Objetivou-se avaliar a sobrevivência e injúrias causadas por Deois flavopicta (Hemiptera: Cercopidae) em pastagens de Urochloa (Syn. Brachiaria) decumbens e U. brizantha, submetidas a tratamento de sementes com fipronil (Amulet®) e tiametoxam (Cruiser 350 FS®), bem como à produtividade de massa seca. A pesquisa foi desenvolvida na Unidade de Pesquisa e Desenvolvimento de São José do Rio Preto/Agência Paulista de Tecnologia dos Agronegócios, sob o delineamento de blocos ao acaso, com seis tratamentos (fatorial 2x3) e quatro repetições. A semeadura foi realizada manualmente, distribuindo 12,0 kg ha-1 de sementes. Para infestação, foram liberados 20 adultos, em gaiolas de 0,40x0,40x0,70 m, aos 49 dias após a semeadura, e a contagem dos insetos nas gaiolas foi conduzida a cada dois dias, por um período de 12 dias, sem a substituição dos insetos mortos. Em avaliação visual foram atribuídas notas de injúrias causadas pela cigarrinha-das-pastagens às gramíneas. Para produtividade, foi efetuada avaliação de massa seca. Os dados obtidos foram submetidos à análise de variância pelo teste F e comparação de média pelo teste de Tukey (p≤0,05). A sobrevivência de D. flavopicta foi maior em pastagem de U. decumbens do que em U. brizantha. O tratamento de sementes com tiametoxam reduziu a porcentagem de cigarrinhas sobreviventes em pastagens em formação, embora não tenha influenciado nas injúrias causadas pelo inseto-praga e na produtividade de massa seca das forrageiras.(AU)

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The present study evaluated the survival and injuries of Deois flavopicta (Hemiptera: Cercopidae) in pastures of Urochloa (Syn. Brachiaria) decumbens and U. brizantha, submitted to seed treatment with fipronil (Amulet®) and thiamethoxam (Cruiser 350 FS®), and dry mass yield. The experiment, carried out at the APTA Experimental Unity, São José do Rio Preto, SP, Brazil, was designed in randomly blocks, with six treatments (factorial 2x3) and four replications. Sowing was manual, with 12.0 kg ha-1 seeds. Twenty adults were released on the plot, in a 40x40x70 cm cage, forty-nine days after sowing. The insects were sampled every two days during twelve days, without replacement of dead insects. Injuries caused by the spittlebug were evaluated by a rating scale and by productivity (dry mass yield). Data were analyzed by F-test and means compared by Tukey's test (p≤0.05). The survival of adults was higher in the U. decumbens pasture than in the U. brizantha pasture. Results show that seed treatment with thiamethoxam reduced the survival of D. flavopicta in pasture formation, but did not influence the injuries caused by insect and the dry mass yield of forage species.(AU)

Objetivou-se avaliar a sobrevivência e injúrias causadas por Deois flavopicta (Hemiptera: Cercopidae) em pastagens de Urochloa (Syn. Brachiaria) decumbens e U. brizantha, submetidas a tratamento de sementes com fipronil (Amulet®) e tiametoxam (Cruiser 350 FS®), bem como à produtividade de massa seca. A pesquisa foi desenvolvida na Unidade de Pesquisa e Desenvolvimento de São José do Rio Preto/Agência Paulista de Tecnologia dos Agronegócios, sob o delineamento de blocos ao acaso, com seis tratamentos (fatorial 2x3) e quatro repetições. A semeadura foi realizada manualmente, distribuindo 12,0 kg ha-1 de sementes. Para infestação, foram liberados 20 adultos, em gaiolas de 0,40x0,40x0,70 m, aos 49 dias após a semeadura, e a contagem dos insetos nas gaiolas foi conduzida a cada dois dias, por um período de 12 dias, sem a substituição dos insetos mortos. Em avaliação visual foram atribuídas notas de injúrias causadas pela cigarrinha-das-pastagens às gramíneas. Para produtividade, foi efetuada avaliação de massa seca. Os dados obtidos foram submetidos à análise de variância pelo teste F e comparação de média pelo teste de Tukey (p≤0,05). A sobrevivência de D. flavopicta foi maior em pastagem de U. decumbens do que em U. brizantha. O tratamento de sementes com tiametoxam reduziu a porcentagem de cigarrinhas sobreviventes em pastagens em formação, embora não tenha influenciado nas injúrias causadas pelo inseto-praga e na produtividade de massa seca das forrageiras.(AU)

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Several strategies have been used to improve soil fertility using integrated crop-livestock (ICL) systems, and the harvest of the accompanying crop used for silage may have several benefits to the soil depending on the quantity and quality of the remaining litter, providing dry matter (DM) for no-tillage systems and nutrient mineralization for the subsequent crop. The objective of this study is to evaluate the rate of decomposition of macro- and micronutrients of the DM of litter produced in ICL systems at different harvest heights in one year. The study was developed at the Experimental Farm of UNESP in Selvíria, Mato Grosso do Sul, Brazil, in the dry season. The study included five replications in plots of 200 m2 and was arranged in a completely randomized block design. The following treatments were analyzed: control sample-degraded pasture of signal grass; Marandu grass-pasture renewal from signal grass to Marandu grass; succession 45-planting of sorghum (forage sorghum cv. Volumax) and crop harvest at the height of 45 cm for silage followed by planting of Marandu grass; simultaneous seeding of Marandu grass and sorghum, and crop harvesting for silage at the height of 15 cm (Marandu + sorghum 15) and 45 cm (Marandu + sorghum 45) from the soil surface. After crop harvesting, proportional amounts of green mass remaining from each unit were collected, transferred to nylon bags, and placed in direct contact with the soil of the respective experimental unit. Each bag was opened every 30 days after closure for up to 270 days. In each bag, the DM, and macro- and micronutrients were analyzed, and the percentage of remaining material, daily decomposition rate, and half-life were calculated. The litter of the Marandu + sorghum 45 treatment contained the highest DM, decomposition rate, and nutrient content...

Tem sido frequente a adoção de estratégias que visem melhorias na fertilidade do solo em sistemas de integração lavoura-pecuária (ILP) e a altura de colheita para ensilagem da cultura acompanhante, pode direcionar diversos benefícios ao solo pela quantidade e qualidade da liteira remanescente, proporcionando massa seca (MS) para o plantio direto e mineralização de nutrientes para a cultura subsequente. Objetivou-se com esse trabalho estudar a dinâmica de decomposição, ao longo de um ano, da MS, macro e micronutrientes de liteiras oriundas de sistemas de ILP com diferentes alturas de colheita. O experimento foi desenvolvido em campo na Fazenda Experimental da UNESP em Selvíria, MS, na condição de sequeiro. O delineamento adotado foi em blocos completos casualizados, com cinco repetições em parcelas de 200 m2. Os tratamentos corresponderam a Testemunha - pastagem degradada de capim-decumbens; Marandu - renovação da pastagem de capim-decumbens para capim-marandu; Solteiro 45 - capim-marandu semeado em sucessão ao sorgo (Sorgo forrageiro cv. Volumax) solteiro que foi colhido a 45 cm de altura para silagem e; capim-marandu semeado simultaneamente com o sorgo que foi colhido para silagem a 15 (Simultâneo 15) e 45 cm (Simultâneo 45) de altura em relação à superfície do solo. Após a colheita da cultura foram amostradas quantidades proporcionais de massa verde remanescentes de cada unidade experimental que foram acondicionadas dentro de sacos de nylon depositados em contato direto com o solo da respectiva unidade experimental. A abertura de cada saco ocorreu a cada 30 dias até 270 dias após o fechamento. Para cada abertura foram analisados a MS, macro e micronutrientes e calculado o percentual de material remanescente, taxa de decomposição diária e o tempo de meia vida. O tratamento Sucessão 45 foi o que proporcionou a maior massa de liteira, taxa de decomposição e maiores teores de nutrientes na MS...

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Dimorphandra wilsonii, a Cerrado endemic Fabaceae tree, is threatened by land-use changes. The few remaining individuals occur in areas dominated by alien grasses like Urochloa decumbens. We tested the impact of nitrogen (N) availability and symbionts' presence on mitigating the effects of competition from U. decumbens. Dimorphandra wilsonii seedlings were 50-week pot-cultivated under limiting (3mM) or non-limiting (10mM) N, with or without U. decumbens, and inoculated or not with a N-fixer (Bradyrhizobium sp.) and an arbuscular mycorrhizal fungus (AMF - Glomus etunicatum), both forming symbioses in the field. Since D. wilsonii seedlings grew more and 'lost' fewer nutrients under the symbionts' presence, symbionts mitigated plant-plant competition. Under limiting N, inoculated D. wilsonii seedlings grew more (despite no nodulation), but N fixation was only suggested when inoculated D. wilsonii seedlings competed with U. decumbens. D. wilsonii13C, and substrate's carbon and respiration suggest that only the microbes performing key functions received plant carbon. Under non-limiting N, inoculated D. wilsonii seedlings became enriched in 13C, substrate accumulated carbon and microbial respiration increased, suggesting a more generalist microbial community. Data suggest inoculating D. wilsonii seeds/seedlings with AMF and N-fixers as a conservation measure. However, long-term field-studies need to confirm these conclusions.

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Avaliaram-se as alturas iniciais (10, 20 e 30 cm) e os períodos de diferimento (171, 141 e 109 dias em 2010; e 131, 100 e 71 dias em 2011) da Urochloa decumbens cv. Basilisk (capim-braquiária). Os fatores foram arranjados em parcelas subdivididas e em delineamento de blocos completos casualizados, com três repetições. Os pastos diferidos por curto período apresentaram menores massas de forragem (5.977 e 6.904 kg/ha de MS em 2010 e 2011, respectivamente). Em 2010, os pastos diferidos por curto período apresentaram menor massa de colmo vivo (942 kg/ha de MS), de lâmina foliar morta (785 kg/ha de MS) e de colmo morto (1.282 kg/ha de MS), maiores números de perfilhos vegetativos (797 perfilhos/m²) e menores de reprodutivos (2 perfilhos/m²), menor índice de tombamento (1,4) e superior massa de lâmina foliar viva (655 kg/ha de MS). Os pastos mais altos apresentaram menor número de perfilhos vegetativos (495 e 431 perfilhos/m² em 2010 e 2011, respectivamente), maiores massas de forragem (5.285 e 5.942 kg/ha de MS em 2010 e 2011, respectivamente), de lâmina foliar morta (968 kg/ha de MS em 2010) e de colmo morto (1.902 kg/ha de MS em 2010). Com base nos resultados obtidos nos dois anos, para utilização em julho, o capim-braquiária pode ser diferido por 71 a 109 dias, com altura inicial de 20 a 30 cm. A altura inicial de 10 cm é recomendada quando se adota período de diferimento acima de 130 dias.

This study aimed to evaluate the initial heights (10, 20, and 30 cm) and deferment periods (171, 141, and 109 days in 2010; and 131, 100, and 71 days in 2011) of Urochloa decumbens cv. Basilisk (signal grass). The factors were arranged in split plot, in a randomized complete block design with three replications. Pastures deferred for a short period had lower masses of forage (5,977 and 6,904 kg/ha of DM in 2010 and 2011, respectively). In 2010, pastures deferred for a short period had lower mass of live stem (942 kg/ha of DM), dead leaf blade (785 kg/ha of DM), and dead stem (1282 kg/ha of DM), higher number of vegetative tillers (797 tillers/m²), fewer reproductive tillers (2 tillers/m²), less falling index (1.4), higher mass of liveleaf blade (655 kg/ha of DM). The higher pastures had fewer vegetative tillers (495 and 431 tillers/m² in 2010 and 2011, respectively), larger masses of forage (5,285 and 5,942 kg/ha of DM in 2010 and 2011, respectively), dead leaf blade (968 kg kg/ha of DM in 2010) and dead stem (1,902 kg/ha of DM in 2010). Based on the results obtained in the two years, for use in July, the signal grass can be deferred for 71-109 days with an initial height of 20 to 30 cm. The initial height of 10 cm is recommended when a deferral period above 130 days is adopted.

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Avaliaram-se as alturas iniciais (10, 20 e 30 cm) e os períodos de diferimento (171, 141 e 109 dias em 2010; e 131, 100 e 71 dias em 2011) da Urochloa decumbens cv. Basilisk (capim-braquiária). Os fatores foram arranjados em parcelas subdivididas e em delineamento de blocos completos casualizados, com três repetições. Os pastos diferidos por curto período apresentaram menores massas de forragem (5.977 e 6.904 kg/ha de MS em 2010 e 2011, respectivamente). Em 2010, os pastos diferidos por curto período apresentaram menor massa de colmo vivo (942 kg/ha de MS), de lâmina foliar morta (785 kg/ha de MS) e de colmo morto (1.282 kg/ha de MS), maiores números de perfilhos vegetativos (797 perfilhos/m²) e menores de reprodutivos (2 perfilhos/m²), menor índice de tombamento (1,4) e superior massa de lâmina foliar viva (655 kg/ha de MS). Os pastos mais altos apresentaram menor número de perfilhos vegetativos (495 e 431 perfilhos/m² em 2010 e 2011, respectivamente), maiores massas de forragem (5.285 e 5.942 kg/ha de MS em 2010 e 2011, respectivamente), de lâmina foliar morta (968 kg/ha de MS em 2010) e de colmo morto (1.902 kg/ha de MS em 2010). Com base nos resultados obtidos nos dois anos, para utilização em julho, o capim-braquiária pode ser diferido por 71 a 109 dias, com altura inicial de 20 a 30 cm. A altura inicial de 10 cm é recomendada quando se adota período de diferimento acima de 130 dias.(AU)

This study aimed to evaluate the initial heights (10, 20, and 30 cm) and deferment periods (171, 141, and 109 days in 2010; and 131, 100, and 71 days in 2011) of Urochloa decumbens cv. Basilisk (signal grass). The factors were arranged in split plot, in a randomized complete block design with three replications. Pastures deferred for a short period had lower masses of forage (5,977 and 6,904 kg/ha of DM in 2010 and 2011, respectively). In 2010, pastures deferred for a short period had lower mass of live stem (942 kg/ha of DM), dead leaf blade (785 kg/ha of DM), and dead stem (1282 kg/ha of DM), higher number of vegetative tillers (797 tillers/m²), fewer reproductive tillers (2 tillers/m²), less falling index (1.4), higher mass of liveleaf blade (655 kg/ha of DM). The higher pastures had fewer vegetative tillers (495 and 431 tillers/m² in 2010 and 2011, respectively), larger masses of forage (5,285 and 5,942 kg/ha of DM in 2010 and 2011, respectively), dead leaf blade (968 kg kg/ha of DM in 2010) and dead stem (1,902 kg/ha of DM in 2010). Based on the results obtained in the two years, for use in July, the signal grass can be deferred for 71-109 days with an initial height of 20 to 30 cm. The initial height of 10 cm is recommended when a deferral period above 130 days is adopted.(AU)

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The objective of this study was to evaluate the effect of supplying different quantities of multiple supplements on the nutritional characteristics and productive performance of heifers during the postweaning phase on Urochloa decumbens pastures during the dry-rainy transition season. Twentyfour heifers (average initial age and weight of 11 mo and 243±6 kg, respectively) were used. The experimental design was completely randomized, with four treatments and six replicates. A supplement containing 25% CP was used, and treatments consisted of the following four levels of supplements: 0, 0.5, 1.0 and 1.5 kg. The animals in the different treatments received a mineral mixture ad libitum. A positive linear effect (P<0.10) was observed on ADG and final body weight with the quantities of supplements. An increasing linear effect (P<0.10) was found on the intakes of DM, OM, CP, EE, NFC and TDN with the elevation in the amount of the supplement provided, which was not observed for NDFap intake. A cubic effect was observed (P<0.10) on the apparent digestibility of OM, CP, NDFap, NFC and concentration of TDN among the quantities of multiple supplements. Supplement levels increased (P<0.10) the digestibility coefficient of EE. An increasing linear response was detected (P<0.10) in urine urea nitrogen excretion, serum urea nitrogen (SUN) and flow of microbial nitrogen (MICN) compounds with the quantities of supplement. No difference was observed (P<0.10) in theefficiency of microbial synthesis between the supplementation levels. The quantities of supplement had a decreasing linear effect (P<0.10) on the relative MICN. In conclusion, supplying higher amounts of multiple supplements during the dry-rainy transition season improves the productive performance and nutritional characteristics of beef heifers reared on pasture.(AU)

O objetivo do trabalho foi avaliar o efeito do fornecimento de diferentes quantidades de suplementos múltiplos sobre as características nutricionais e desempenho produtivo de novilhas durante a fase de recria em pastagens com Urochloa decumbens no período de transição seca-águas. Foram utilizadas 24 novilhas com idade e peso médio inicial de 11 meses e 243±3 kg, respectivamente. O delineamento foi inteiramente casualizado com quatro tratamentos e seis repetições. Utilizou-se um suplemento com 25% de PB. Os tratamentos consistiam em quatro quantidades de suplementos: 0; 0,5; 1,0 e 1,5 kg respectivamente. Os animais dos diferentes tratamentos receberam mistura mineral ad libitum. Observou-se efeito linear positivo (P<0,10) no GMD e peso corporal final (PCF) com as quantidades de suplementos. Foi verificado efeito linear crescente (P<0,10) no consumo de MS, MO, PB, EE, CNF e NDT com o fornecimento de maiores quantidades de suplemento; efeito não apresentado no consumo de FDNcp. Evidenciou-se efeito cúbico (P<0,10) sobre a digestibilidade aparente da MO, PB, FDNcp, CNF e concentração de NDT entre as quantidades de suplementos múltiplos. As quantidades de suplementos aumentaram (P<0,10) o coeficiente de digestibilidade do EE. Verificou-se comportamento linear crescente (P<0,10) sobre a excreção urinária de nitrogênio uréico (NUU), nitrogênio uréico no soro (NUS) e fluxo de compostos nitrogenados microbianos (NMIC) com as quantidades de suplementos. Não foi observada diferença (P<0,10) das quantidades de suplementação sobre a eficiência de síntese microbiana. As quantidades de suplementos afetaram de forma linear decrescente (P<0,10) o NMICR.Conclui-se que o fornecimento de maiores quantidades de suplementos múltiplos durante a época de transição seca-águas melhora o desempenho produtivo e características nutricionais de novilhas de corte criadas em pastagens.(AU)

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