ABSTRACT. Combinations between crop intercropping and forage production in a no-tillage system are not well established for environments under low water retention and soil fertility conditions. Our study aimed to evaluate the potential interactions between soybean-grass intercropping with residual nitrogen in a no-tillage system. The experimental design was a randomized block with four replications in a subdivided plot scheme. The main plots in the summer season were: 1) soybean monoculture; 2) soybean - Aruana Guinea grass (Megathyrsus maximus cv. Aruana) intercropping, and 3) soybean - Congo grass (Urochloa ruziziensis cv. Comum) intercropping. The subplots were the nitrogen rates of 0, 50, 100, and 150 kg ha-1, applied as side-dressing in maize and grasses during the autumn-winter season. Here, the results of the summer seasons are shown. To do so, the parameters evaluated were soybean agronomic traits, dry biomass production, and macronutrient concentrations of plants intercropped. The main effects and interactions were studied. Our findings showed that soybean-Aruana Guinea grass intercropping is an alternative to no-tillage system implementation. Moreover, residual nitrogen from the autumn-winter season directly interfered with the dry biomass production of grasses intercropped with soybeans in the summer season. In short, the systems studied seem suitable for implementing a no-tillage system, which aims to neutralize degraded pastures and produce forage for ensilage. Despite the changes in macronutrient concentrations within the intercropping system and residual nitrogen, and among intercropped crops over the years, Congo grass intercropped with soybeans in the summer season showed great capacity for phosphorus, potassium, and magnesium cycling.

ABSTRACT The objective of our study was to evaluate the effect of the use of legume (Arachis pintoi) or nitrogen fertilization on animal performance, characteristics of carcass and meat, and fatty acids profile of crossbred steers on Megathyrsus maximus cv. Aruana pasture, overseeded with temperate grasses. The experimental design was completely randomized, with three treatments and three replicates. The experiment was carried out from June to October (127 d). The treatments were: Low-N: 100 kg of N/ha; Medium-N: 200 kg of N/ha; and Legume: Arachis pintoi + 100 kg of N/ha. The pasture with higher nitrogen fertilization (N200) showed a more significant forage mass yield. The mixed grass with legumes presented a higher concentration of saturated fatty acids and saturated:unsaturated ratio in the meat. However, the grass pastures resulted in a higher content of unsaturated fatty acids in the meat. The other pasture variables, and characteristics of carcass and meat were not influenced by the treatments. The increase in nitrogen fertilization, from 100 to 200 kg/ha, and Arachis pintoi mixed with Aruana grass pasture overseeded with black oat and ryegrass does not affect the daily weight gain and the carcass and meat characteristics of the steers. The grass-legume mixture decreases the total concentration of unsaturated fatty acids in meat without influencing the concentration of polyunsaturated fatty acids.

Resumen El objetivo de la presente investigación fue evaluar el efecto de diferentes niveles de suplementación concentrada (0 %, 1,5 %, 3,0 %, en relación con el peso vivo) y dos especies forrajeras como Megathyrsus maximus cv. Aruana y Brachiaria brizantha cv. Marandú en el rendimiento del quinto cuarto en corderos Suffolk. En total, 36 corderos machos enteros fueron distribuidos en 12 piquetes de 32 m × 32 m. Los animales recibieron sal y agua ad libitum durante el experimento, así como su correspondiente ración concentrada ofrecida diariamente a las 8:00 a. m. Un puntaje de condición corporal de 2,5 a 3,0 fue utilizada como parámetro para la faena. El diseño fue completamente al azar en un arreglo factorial 3 × 2 (tres niveles de suplementación y dos tipos de pasturas). Se evaluó el peso corporal vacío (PCV), consumo de materia seca (CMS), ganancia de peso diario (GPD), componentes del quinto cuarto (CQC), tracto gastrointestinal y víscera roja, blanca y verde. El PCV, CMS, GPD y CQC fueron influenciados (p < 0,05) por los niveles de suplementación concentrada y tipos de pasturas, menores para animales sin suplementación en pastura Marandu. Asimismo, la cabeza, las patas, la sangre, el corazón, el hígado, el riñón, la víscera roja y la grasa omental e interna fueron inferiores (p < 0,05) en animales sin suplementación. Rumen retículo (lleno y vacío) y víscera blanca (lleno y vacío) fueron independientes del nivel de suplementación y tipos de pasturas. La no suplementación concentrada provoca menor desarrollo de los principales órganos vitales del cordero, más aún en pastura Marandú.

Abstract The objective of the present investigation was to verify the effect of different levels of concentrate supplementation (0 %, 1.5 %, 3.0 % in relation to live weight) and two forage species such as Megathyrsus maximus cv. Aruana and Brachiaria brizantha cv. Marandu in fifth quarter performance in Suffolk lambs. In total, 36 entire male lambs were distributed in 12 pickets of 32 m × 32 m. The animals received salt and water ad libitum during the experiment and the concentrated ration offered daily at 08:00 AM. Body condition score of 2.5 to 3.0 was used as parameters for slaughter. The design was completely randomized in a 3 × 2 factorial scheme (three levels of supplementation and two types of pasture). Empty body weight (EBW), dry matter intake (DMI), daily weight gain (DWG), fifth quarter components (FQC), gastrointestinal tract and red, white and green viscera were evaluated. EBW, DMI, DWG and FQC were influenced (P < 0.05) by the levels of concentrated supplementation and types of pastures, lower for animals without supplementation in Marandu pasture. Likewise, head, foot, blood, heart, liver, kidney, red viscera, omental and internal fat were lower (P < 0.05) in animals without supplementation. Rumen reticulum (full and empty) and white viscera (full and empty) independent of the level of supplementation and types of pasture. The non-concentrated supplementation causes less development of the main vital organs of the lamb, even more in Marandu pasture.

Abstract Thirty-two Santa Inês male lambs, not castrated, were distributed in a randomized block design to evaluate the effects of different tropical forage cultivars (two Panicum maximum (Syn. Megathyrsus maximus): Aruana and Massai, and two Brachiaria brizantha (Syn. Urochloa brizantha) Marandu and Piatã) on carcass characteristics, quality, physical composition, and meat chemistry. The data were subjected to an analysis of variance, and the means compared using the Tukey test at 5% significance. There was no effect of cultivars on body weight, slaughter weight, and biometric measurements of the carcass. The Aruana and Piatã cultivars provided higher weights of hot and cold carcasses when compared to the Massai and the Marandu had no significant differences compared to the others. The animals kept in the pasture of the Aruana cultivar showed higher shank yields. However, forage cultivars did not affect the ribeye area or subcutaneous fat thickness. There was also no effect of cultivar on pH, temperature, cooking losses, cooling losses, and meat shear strength. The cultivars did not change the quality and composition of the meat. However, the Aruana, Piatã, and Marandu cultivars were the ones that provided higher carcass weights and ham yields.

ABSTRACT. This study aimed to evaluate the morphogenic and structural characteristics of six Panicum maximum cultivars during the establishment period. A completely randomized block design with four replicates and six treatments (Tamani, Mombaça, Massai, Tanzania, Aruana and Zuri cultivars) was used. Morphogenic (leaf appearance rate, leaf elongation rate e stem elongation rate), structural (final leaf length, tiller population density e number of leaves per tiller) and productive (forage mass, leaf blade mass, stem mass, senescent material mass and leaf:stem ratio) characteristics were evaluated. There was no difference (p > 0.05) between the cultivars in terms of the number of live leaves per tiller (2.95 leaves/tiller). Mombaça cultivar had (p < 0.05) higher canopy height (50.64 cm) compared with other cultivars. The highest (p < 0.05) tiller population density was observed in Tamani (235.90 tillers m-2) and Massai (201.60 tillers m-2) cultivars. Leaf lifespan (54.18 days), phyllochron (17.40 days/leaf) and leaf senescence rate (0.87 cm tiller day-1) were not different (p > 0.05) between cultivars. However, leaf appearance rate was higher (p < 0.05) in Tanzania (0.07 leaves tiller day-1) than in Aruana cultivar (0.05 leaves tiller day-1). Leaf blade mass was higher (p < 0.05) in Mombaça cultivar (1518.31 kg DM ha-1), whereas Massai showed higher (p < 0.05) leaf:stem ratio (9.25). Panicum cultivars Tamani, Tanzania and Massai establishment after 75 days, while the other cultivars establish at 105 days of sowing in the Brazilian Northeast.

Abstract The objective was to evaluate the productive and structural characteristics of tropical grasses and the performance of sheep supplemented during the dry season. The treatments consisted of Marandu, Piatã, Massai and Aruana cultivars managed under intermittent stocking with seven occupation days and 35 d of rest, with a variable stocking rate. The evaluated variables were the forage masses, the morphological components, the chemical composition of the pasture and sheep performance. The forage mass was similar among the cultivars, while the leaf blade mass and percentage were higher in the Massai cultivar. There were differences between the cultivars for the NDF, ADF, ADL and ash contents in the two grazing cycles. The lowest gains per animal and gain per area were observed in the Aruana grass pastures, while there were no differences for these variables among the other cultivars. Massai, Marandu and Piatã cultivars can be used as a forage option for the dry period when associated with protein supplementation for sheep being raised for meat.

Resumen El objetivo fue evaluar las características productivas y estructurales de los pastos tropicales y el rendimiento de las ovejas suplementadas durante la estación seca. Los tratamientos consistieron en las variedades Marandú, Piatã, Massai y Aruana manejadas bajo una media intermitente con siete días de ocupación y 35 días de descanso, con una carga variable. Las variables evaluadas fueron producción de forraje, los componentes morfológicos, la composición química, de los pastos y la productividad de las ovejas. La producción de forraje fue similar entre las diversas variedades, mientras que la producción y el porcentaje de hojas fueron mayores en el la variedad Massai. Hubo diferencias entre los cultivos para los contenidos de FDN, FDA, LDA y cenizas en los dos ciclos de pastoreo. Las ganancias más bajas por animal y por área se observaron en los pastizales de Aruana, mientras que no hubo diferencias para estas variables entre los otros cultivos. Las variedades Massai, Marandú y Piatã se pueden utilizar como una opción de forraje para la época seca cuando están asociados con la suplementación proteica para ovejas criadas para carne.

RESUMO O objetivo com este estudo foi avaliar o efeito da substituição do farelo de soja pela torta de mamona destoxificada sobre a espermatogênese em ovinos. Foram utilizados 24 ovinos, com peso médio de 29±0,8kg e 9 meses de idade, distribuídos aleatoriamente em três tratamentos: T1= 0%, T2= 50% e T3= 100% de substituição do farelo de soja pela torta de mamona destoxificada. Os animais foram alimentados com pastagem de capim Aruana (Panicum maximum cv. Aruana) e ração durante 90 dias. Por ocasião do abate, coletou-se os testículos para mensurações e avaliação da espermatogênese. Os dados foram avaliados quanto à normalidade por meio do teste de Shapiro-Wilk e utilizou-se a Análise de Variância com 5% de significância. Não houve efeito da substituição do farelo de soja pela torta de mamona destoxificada nos níveis testados (P>0,05) para nenhuma das variáveis avaliadas. O rendimento médio da espermatogênese foi de 72,91 espermátides arredondadas produzidas a partir de uma espermatogônia; a média do número total de células germinativas sustentadas por uma de célula de Sertoli foi 12,09; a média da reserva espermática testicular total foi de 31,82x109 e de 238,28x106 por grama de testículo; a média da produção espermática diária foi de 3,03x109 e de 22,69x106 por grama de testículo e o número total de células de Sertoli foi de 4,15x109 e de 34,51x106 por grama de testículo. Os resultados demonstram que é possível substituir 100% do farelo de soja pela torta de mamona destoxificada na dieta de ovinos sem prejuízos no processo de espermatogênese.

ABSTRACT The objective was to evaluate the effect of replacing soybean meal with the detoxified castor bean cake on testicular morphometry and spermatogenesis of sheep. Were used 24 uncastrated, 9-month old sheep weighing 29±0.8 kg they were randomly distributed among three treatments: T1 = 0%, T2 = 50%, and T3 = 100% substitution of soybean meal with detoxified castor bean cake. The animals were fed with Aruana grass pastage (Panicum maximum ‘Aruana’) and a ration for 90 days. After slaughtering, the testicles were collected and histological slides were prepared with tissue fragments. The data were evaluated for normality using the Shapiro-Wilk test, and analysis of variance was carried out at 5% level of significance. Substitution of soybean meal with detoxified castor bean cake had no effect on any of the assessed variables at the tested levels (P >0.05). The mean yield of spermatogenesis was 72.91 rounded spermatids per spermatogonium; the mean of total number of germ cells held by a Sertoli cell was 12.09; the mean of the testicular spermatic reserve was 31.82×109 and that per testicular gram was 238.28×106; the mean of daily spermatic production was 3.03×109 and that per testicular gram was 22.69×106; and the total number of Sertoli cells was 4.15×109 and that per testicular gram was 34.51×106. The results show that it is possible to replace 100% of the soybean meal with detoxified castor bean cake in sheep diet without any effects on spermatogenesis; however, it is important to perform seminal evaluations in future studies.

Abstract Mycorrhizae are important components of agroecosystems and the diversification of crops stimulates the abundance of arbuscular mycorrhizal fungi and the participation of symbiosis in plant growth. This experiment examined mycorrhizal assessment, chemical and microbiological soil attributes in a maize-forage grasses intercropping compared to a maize-monocropping system. A complete randomized block design was used with crop systems installed under no-till management with three replicates, as follow: Maize (Zea mays L.); Panicum maximum Jacq. cv. Aruana; Urochloa humidicola (Rendle.) Schweickerdt.; Maize-P. maximum intercropping and Maize-U. humidicola intercropping. In 2015/2016 season, intercropping maize with Panicum maximum Jacq. cv. Aruana or Urochloa humidicola (Rendle.) Schweickerdt. promoted similar effects (Tukey test, p<0.05) to monocropped maize under no-till system on soil chemical and biochemical parameters related to carbon cycling in the soil surface layer, as well as the dynamics of arbuscular mycorrhizal symbiosis in tropical soils, managed for a period of more than six years. Similar grain yield was verified among maize crop systems. This result indicates that intercropping maize-tropical forage grasses represents an alternative for monocropped grains, a very common practice that is used in intensive management, being able to guarantee equivalent productivities and to combine grain production with crop-livestock systems. As a result, intercropping promotes the diversification of the property's income source, adding environmental gains, such as more efficient land use by cultivated plants, keeping soil constantly cultivated, storing carbon and contributing to minimize the impact of climate change on agricultural systems and the sustainability of food production.

Objectives of this study were to evaluate effects of grazing tropical forage species and level of supplementation with grain on characteristics of lamb meat. Ninety-day-old lambs (n = 36) (22.54 ± 2.72 kg) were randomly assigned to a 2 x 3 factorial arrangement of pasture types (Aruana and Marandu) and levels of concentrate supplementation (0%, 1.5% and 3% of bodyweight). Water retention capacity, shear force, weight loss after cooking, pH, colour, and intramuscular lipid content of the meat were evaluated. A panel of 145 consumers evaluated the appearance, flavour, fat flavour, odour, and softness of the meat and provided an overall assessment. Supplementation at 3% of bodyweight reduced the luminosity of the meat. The appearance of meat from lambs that grazed Aruana grass was deemed preferable to that of meat from lambs that grazed Marandu grass. Total branched-chain fatty acids (BCFAs) were increased when grazing Marandu grass compared to Aruana grass. Lambs supplemented with concentrate had reduced BCFA/kg of meat and its content of both monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids were increased. Supplementation with concentrate at 1.5% and 3.0% of bodyweight increased n-6 PUFAs by 16.8% and 90.0%, decreased n-3 PUFAs by 49.7% and 35.9%, and thus increased the n-6/n-3 ratio by 135.0% and 183.8%, respectively. Lambs that were finished on grass without supplementation had a more healthful fatty acid profile and received better scores for flavour and global appreciation. To improve the quality of fatty acids in the meat, the pasture system is recommended.

Resumo As literaturas de ambidestria e capacidades dinâmicas contribuíram para discussões de gestão estratégica que buscam explicar como empresas alcançam e sustentam vantagens competitivas. Porém, poucos trabalhos dedicaram-se a entender como essas literaturas se inter-relacionam no nível de microfundamentos de sensing, seizing e reconfiguring de Teece (2007). A fim de preencher essa lacuna, investigamos trabalhos anteriores sobre teorias de estratégia e organizações que discutem a relação ambidestria-capacidades dinâmicas mediante uma revisão sistemática da literatura complementada por uma técnica de bola de neve (também propomos um modelo conceitual). A revisão da literatura que integra as duas abordagens mostra que os autores geralmente entendem a ambidestria como uma capacidade dinâmica. Além disso, nosso modelo revela elementos convergentes entre as duas literaturas como aprendizado; fontes de informação; design organizacional; gestão de recursos escassos, aumento de recursos através de terceirização e alianças; o papel da alta gerência e a participação das equipes nas decisões; por fim, a relevância da especialização de ativos e a governança organizacional. Com este artigo, pretendemos contribuir para a literatura ao sintetizar os trabalhos anteriores que relacionaram ambidestria e capacidades dinâmicas, propor um modelo conceitual baseado nos microfundamentos e identificar avenidas para pesquisas futuras.

Abstract The ambidexterity and dynamic capabilities (DCs) literature have contributed to strategic management discussions that seek to explain how firms achieve and sustain competitive advantages. However, few papers are devoted to understanding how they interrelate at Teece’s (2007) micro-foundations of sensing, seizing, and reconfiguring capabilities level. To fill these gaps, we investigate previous works on strategy and organization theories which discuss the ambidexterity-DCs relationship through a systematic literature review complemented by using a snowball technique and then propose a conceptual framework. Review of the literature that integrates the two approaches shows that authors usually understand ambidexterity as a DC. Also, our framework reveals convergent elements between the two kinds of literature, such as learning; sources of information; organizational design; management of scarce resources; increase of resources through outsourcing and alliances; the role of top managers and teams’ participation in decisions; and the relevance of asset specialization and organizational governance. This article aims to contribute to the literature by synthesizing early work relating ambidexterity and DCs; proposing a conceptual framework based on DCs’ micro-foundations; and identifying avenues for future research.

Resumo Os fungos têm uma grande capacidade para produzir enzimas que são capazes de degradar compostos. De acordo com esse fato, os corantes solúveis são frequentemente utilizados como maneira de avaliação e seleção de linhagens com potencial de biodegradação. O presente estudo verificou a capacidade de linhagens de Pleurotus sp. na degradação do corante azul de metileno, a fim de identificar linhagens com potencial para processos de biorremediação. Desse modo, um total de sete linhagens de Pleurotus sp. foram cultivadas em meio líquido de batata com o corante azul de metileno nas concentrações de 0,02 g L-1 e 0,04 g L-1. Os resultados das absorvâncias mostraram que todos os isolados foram visivelmente capazes de reduzir a coloração do meio, após sete dias de crescimento fúngico. Observou-se ainda, uma redução de aproximadamente 80% na coloração para as linhagens denominadas ERY, HI e SB em comparação com o controle. Assim, foi possível constatar que essas linhagens podem ser utilizadas em bioprocessos de remoção de cor e na biodegradação de compostos poluentes.

Abstract Fungi have a large capacity to produce enzymes that are capable of degrading compounds. In this regard, soluble dyes are often used as a means of evaluating and selecting strains with potential for biodegradation. This study verified the capacity of the strains of Pleurotus sp. in degrading methylene blue dye, in order to identify the strains with potential for the bioremediation. For this reason, a total of seven strains of Pleurotus sp. were grown in a potato liquid medium with the methylene blue dye at the concentrations of 0.02 g L-1 and 0.04 g L-1. The results of the absorbances showed that all the isolates were visibly able to reduce the media staining following seven days of growth. However, a reduction of approximately 80% in the staining was observed for the strains named ERY, HI, and SB compared to the control. Thus, it was observed that these strains could be used in the color removal bioprocesses and in the biodegradation of pollutant compounds.

RESUMO: O objetivo deste estudo foi avaliar a suscetibilidade das forrageiras Urochloa ssp. e Megathyrsus maximus a duas doses de herbicida glyphosate, visando facilitar o estabelecimento de culturas nos sistemas integrados de produção agropecuária. O delineamento adotado foi o de blocos casualizados com parcelas subdivididas em faixa e seis repetições. Os tratamentos nas parcelas principais foram constituídos das forrageiras: Urochloa ruziziensis, U. decumbens, U. brizantha cvs. Xaraés, BRS Piatã e BRS Paiaguás, Megathyrsus maximus cvs. Aruana e BRS Tamani e, nas subparcelas, doses de herbicida glyphosate: 0,72 e 1,44 kg e.a. ha-1. A estimativa da porcentagem de controle constituiu-se na atribuição de notas na escala de zero (perfilhos totalmente vivos) a 100 (perfilhos totalmente mortos), realizada aos 7, 14, 21 e 28 dias após a aplicação do herbicida. A dose de 0,72 kg e.a. ha-1 não foi eficiente para o controle das forrageiras, mas foi possível identificar os genótipos mais suscetíveis, como U. ruziziensis e BRS Piatã. A dose de 1,44 kg e.a. ha-1 foi satisfatória para o controle (³80%) de U. ruziziensis, U.brizantha cv. BRS Paiaguás e M. maximum cv. Aruana, aos 17, 18 e 18 dias de intervalo de dessecação, respectivamente. Conclui-se que a suscetibilidade das forrageiras ao herbicida glyphosate varia entre espécies e cultivares. Os capins U. ruziziensis, BRS Paiaguás e Aruana são dessecados com reduzida dose de herbicida, apresentam curto intervalo de dessecação e podem contribuir para a diversificação das forrageiras utilizadas nos sistemas integrados de produção agropecuária.

ABSTRACT: The purpose of this study was to evaluate forage plant susceptibility in Urochloa ssp. and Megathyrsus maximus with two glyphosate herbicide doses, to increase the efficiency of integrated crop-livestock farming systems. A randomized block design was adopted, in a split-plot arrangement, with six replications. In the main plots, the following treatments were established: Urochloa ruziziensis, U. decumbens, U. brizantha cvs. Xaraés, BRS Piatã and BRS Paiaguás, Megathyrsus maximus cvs. Aruana and BRS Tamani; in the subplots, there were doses of glyphosate herbicide; 0.72 and 1.44 kg a.e. ha-1. The estimated control percentage was consisted of a grading scale from zero (fully living tiller) to 100 (fully dead tillers), assigned 7; 14; 21 and 28 days after herbicide application. The 0.72 kg a.e. ha-1 glyphosate dose was not effective for forage control, but it was possible to identify the most susceptible genotypes, such as U. ruziziensis and BRS Paiaguás. The 1.44 kg a.e. ha-1 dose was satisfactory in controlling (³80%) the grasses U. ruziziensis, U. brizantha cv. BRS Paiaguás and M. maximum cv. Aruana at 17, 18 and 18 days of desiccation intervals, respectively. In conclusion, the susceptibility of forage plants to herbicide glyphosate varies among species and cultivars. U. ruziziensis, BRS Paiaguás and Aruana grasses are desiccated with reduced herbicide doses and short desiccation intervals, and can contribute to the diversification of the forage used in integrated crop-livestock farming systems.

Abstract The objective of this study was to analyze the genetic diversity among and within populations of Brazil nut by Amplified Fragment Length Polymorphism markers. Five populations with 30 plants each of the state of Amazonas, Brazil, two populations from the Farm Aruanã (Aruanã Carolina and Aruanã Brastor), in Itacoatiara, one from the municipality of Parintins and two from the municipality of Manaus (Instituto Federal do Amazonas - IFAM and Manaus Airport) were evaluated. Four primer combinations were used and 306 polymorphic bands (93.3%) were obtained. Genetic differentiation within and among populations was tested by analysis of molecular variance. The presence of genetic divergence was greater within populations (51.88%) than among populations (48.11%) and the Fst value was 0.48. Two groups were formed by interpopulation grouping: the first consisted of populations from plantations in Aruanã Carolina, Aruanã Brastor and Manaus IFAM, and the second of natural populations from Parintins and Manaus Airport.

Resumo A quantidade de recursos hídricos deve ser garantida com a devida qualidade. Neste contexto, o trabalho objetivou caracterizar a qualidade da água do rio Setúbal utilizando o Índice de Qualidade da Água (IQA) e os padrões estabelecidos na Resolução do CONAMA 357/2005, após a construção da barragem de Setúbal, no Município de Jenipapo de Minas - MG. Para a caracterização da qualidade da água, seis amostras foram coletadas bimestralmente em dois pontos estratégicos do rio entre junho de 2015 a junho de 2016, sendo analisados os parâmetros: potencial hidrogeniônico (pH), oxigênio dissolvido (OD), temperatura, demanda bioquímica de oxigênio (DBO), nitrato (NO3 -), fósforo (PO4 3-), cloreto, turbidez, sólidos totais, ferro total, coliformes totais e Escherichia coli. O IQA foi calculado a partir da metodologia proposta pelo IGAM. De acordo com os resultados, a construção da barragem de Setúbal pode ter contribuído para a alteração de alguns parâmetros físico-químicos e biológicos da água do rio Setúbal. Nos dois pontos de amostragem, a água apresentou um IQA predominantemente de nível médio, porém com algumas variáveis em desconformidade com o enquadramento do rio que é de classe 2.

Abstract The quality of water resources must be guaranteed. In this context, this study aimed to characterize the water quality of the river Setúbal using the Water Quality Index (WQI) and standards set by CONAMA Resolution 357/2005, after the construction of Setúbal dam in the municipality of Jenipapo de Minas - MG. For the characterization of water quality, six samples were collected bimonthly between June 2015 to June 2016 at two strategic river points and the following parameters were analyzed: hydrogen potential (pH), dissolved oxygen (DO), temperature, biochemical demand oxygen (BDO), nitrate (NO3-), phosphorus (PO4 3-), chloride, turbidity, total solids, total iron, total coliforms and Escherichia coli. The WQI was calculated using the methodology proposed by IGAM. The results showed that the construction of Setúbal dam may have influenced changes in some of the physiochemical and biological parameters of Setúbal river’s water. The medium WQI level predominated in the two sampling points, but some variables did not reflect the Class2 river category.

Resumo: O objetivo deste trabalho foi avaliar a produção de grãos de soja (Glycine max) e o estabelecimento de forrageiras perenes, em cultivo consorciado. A soja foi avaliada em cultivo solteiro e consorciada com os capins: Megathyrsus maximus, cultivares Aruana e BRS Tamani; Urochloa brizantha, cultivares Xaraés, BRS Piatã e BRS Paiaguás; U. decumbens; e U. ruziziensis. Utilizou-se o delineamento experimental de blocos ao acaso, com sete repetições, nas safras de 2011/2012 e 2012/2013. No cultivo consorciado, as forrageiras foram semeadas 21 e 14 dias após a emergência da soja, na primeira e na segunda safra, respectivamente. O rendimento de grãos da soja solteira e o da consorciada não diferiram, exceto nos cultivos soja + U. ruziziensis e soja + 'BRS Paiaguás', que apresentaram menor rendimento no segundo ano de avaliação. O capim 'BRS Tamani' foi o mais adequado para estabelecimento em consórcio com a soja, ao se considerar suas características morfológicas e seu baixo potencial de competição. O consórcio de soja e forrageiras perenes contribui para supressão do crescimento de plantas daninhas e, de maneira geral, não compromete o rendimento da soja.

Abstract: The objective of this work was to evaluate soybean (Glycine max) grain yield and the establishment of perennial intercropped forages. Soybean was evaluated in sole crop and intercropped with the following forages: Megathyrsus maximus, Aruana and BRS Tamani cultivars; Urochloa brizantha, Xaraés, BRS Piatã, and BRS Paiaguás cultivars; U. decumbens; and U. ruziziensis. A randomized complete block design was used, with seven replicates, in the 2011/2012 and 2012/2013 crop seasons. In the intercropped system, the forages were sown 21 and 14 days after soybean emergence, in the first and second crop seasons, respectively. Grain yield did not differ for soybean in sole crop or intercropped, except for soybean + U. ruziziensis and soybean + 'BRS Paiaguás', which were less productive in the second year of evaluation. The 'BRS Tamani' forage was the most suited for intercropping with soybean, considering its morphological characteristics and its low competition potential. Soybean intercropped with perennial forages contributes to suppress weed growth and, overall, does not compromise soybean yield.