ABSTRACT Phosphate solubilizing microorganisms (PSM) and arbuscular mycorrhizal fungi (AMF) represent alternative strategies to reduce the cost and increase the production of cagaita (Eugenia dysenterica) seedlings associated with different substrates. This study aimed to assess the effect of inoculating PSM and AMF in different substrates for cagaita (Eugenia dysenterica) culturing. The experiment was installed with a completely randomized design, using a 4 × 2 factorial scheme, with four inoculation treatments (PSM, AMF, PSM + AMF, and Control - absence of inoculation), and two soils substrates (pure sandy substrate and mixed substrate). The substrates and microorganism had influence in cagaita seedling growth. The pure substrate conferred better performance of plant growth parameters. In this substrate, cagaita seedlings had higher stem diameter, shoot fresh and dry weight, root volume and root dry weight. The cultivation of seedlings in pure substrate inoculated with AMF and PSM provided greater Mo content in the leaves. The higher root volume of cagaita seedlings was obtained with the inoculation of PSM. A sandy substrate seems to be the most adequate for the cultivation of cagaita seedlings. In addition, co-inoculation provides higher Fe, Mg, and K content in the leaves, as this work showed.

RESUMEN Los microorganismos solubilizadores de fosfato (PSM) y los hongos micorrízicos arbusculares (HMA) representan estrategias alternativas para reducir el costo y aumentar la producción de plántulas de cagaita (Eugenia dysenterica) asociadas a diferentes sustratos. Este estudio tuvo como objetivo evaluar el efecto de la inoculación de PSM y HMA en diferentes sustratos para el cultivo de cagaita (Eugenia dysenterica). El experimento se instaló con un diseño completamente al azar, utilizando un esquema factorial 4 × 2, con cuatro tratamientos de inoculación (PSM, HMA, PSM + HMA y Control - ausencia de inoculación), y dos sustratos de suelo (sustrato arenoso puro y sustrato mixto). Los sustratos y microorganismos influyeron en el crecimiento de las plántulas de cagaita. El sustrato puro propició un mejor desempeño de los parámetros de crecimiento de las plantas. En este sustrato, las plántulas de cagaita presentaron mayor diámetro de tallo, masa fresca y seca de brotes, volumen de raíz y masa seca de la raíz. El cultivo de plántulas en sustrato puro inoculadas con HMA y PSM proporcionó mayor contenido de Mo en las hojas. El mayor volumen de raíces de plántulas de cagaita se obtuvo con la inoculación de PSM. Un sustrato arenoso parece ser el más adecuado para el cultivo de plántulas de cagaita. Además, la coinoculación proporciona un mayor contenido de Fe, Mg y K en las hojas, como mostró este trabajo.

abstract background: the recovery of areas impacted by mining activities is a major challenge and requires knowledge of how the biological and biochemical processes of the soil as well as the establishment of plant species are affected by mining residue. in this work, the influence of deposition of iron mining mud and tailings on soil biochemical attributes and the initial development of tree seedlings was studied in a simulated event in the greenhouse. pots (n = 27) with natural soil (2.0 kg) received deposition (280 ml) of iron mining mud or tailings and by three-month was cultivated with urochloa decumbens. at the end of this period, part of the pots was sampled and the soil biochemical activities were evaluated. then tree seedlings (schinus terebinthifolius and eremanthus incanus) were planted and cultivated for a year, when then shoot (sdw) and roots (rdw) dry weight were evaluated. results: deposition of iron mining mud and tailings did not affect microbial biomass carbon or basal soil respiration, however both conditions reduced (p < 0.05) β-glucosidase activities by up to 30%, and the easy extractable glomalin by about 19%. in addition, the mud deposition reduced (p < 0.05) the sdw and rdw of s. terebinthifolius by about 21% and 24%, respectively. nevertheless, uruchloa decumbens and eremanthus incanus had no variation in dry weight production between treatments, so they have good ability to grow settle in soil affected by mining residue. conclusion: this study shows that the sequential planting of u. decumbens and e. incanus can be an alternative for use in environments with deposition of iron mining tailings.

ABSTRACT High rates of agricultural gypsum, above the recommended levels, have been used on a regular basis to deepen plant roots and to alleviate recurrent water stress in Cerrado areas. However, very little is known about the consequences of this practice to arbuscular mycorrhizal fungi (AMF). Therefore, the objective of this study was to evaluate whether or not applying high rates of agricultural gypsum affects the mycorrhizal fungi community, glomalin content and coffee yield. The study rates were: 0; 3.5; 7.0; 14 and 56 t·ha-1 of agricultural gypsum applied in the planting row of the coffee plantation on top of the previous recommended gypsum application. Samples were collected for analysis at the depths of 0-20, 20-40 and 40-60 cm at the end of dry and rainy seasons of the year. In the coffee plantation, 16 AMF species were identified. Gigaspora sp. and Glomus macrocarpum were dominant in all situations. The rate of 7 t·ha-1 favored greater diversity of AMF species and the rate of 56 t·ha-1 reduced AMF diversity and mycorrhizal colonization in deeper layers. In the rainy season, there was a linear decrease of easily extractable glomalin-related soil protein (EE-GRSP) levels as the agricultural gypsum rate was increased. Coffee yield was reduced with the highest gypsum rate (56 t·ha-1), even though the coffee plantation had higher phosphorus contents in beans and leaves. This may have resulted from a number of reasons, including a negative effect on the AMF community.

ABSTRACT. The present study aimed to select efficient arbuscular mycorrhizal fungi (AMF) for sugarcane growth and P nutrition in four soils that spontaneously contained dark septate endophytes (DSE). The effect of nine AMF isolates was evaluated individually in sugarcane presprouted seedlings (SP81-3250) grown under greenhouse conditions for a 120-day period. The isolates that stimulated plant growth in the soils with low P availability were Acaulospora colombiana (ACOL), Claroideoglomus etunicatum (CETU), Gigaspora margarita (GMAR), Rhizophagus clarus (RCLA) and Scutellospora calospora (SCAL). Compared to the Yellow Argisol, which had the highest P level, the Red-Yellow Argisol, with an intermediate P content, increased plant height. Compared to the other treatments, inoculation with ACOL, RCLA, and SCAL resulted in higher foliar P content in plants grown in soils with high to intermediate P levels. Root colonization by AMF and DSE was verified in the plants, with the coexistence of both fungal groups in the same plant and/or root fragment. However, AMF colonization was low compared to DSE colonization. The cooccurrence of DSE and AMF was higher in the plants inoculated with ACOL, RCLA, SCAL, and Dentiscutata heterogama. ACOL, CETU, GMAR, RCLA, and SCAL are AMF isolates that have the potential to establish a mycorrhizal inoculant for sugarcane that would be effective in several soils.

RESUMO A produção de mudas de clone de Coffea arabica L. é uma das alternativas de maior demanda para cafeicultores, existindo programas de melhoramento através da técnica de embriogênese somática, no entanto, os clones apresentam dificuldades de pegamento na fase de aclimatação em casa de vegetação elevando custo de produção. Uma alternativa testada com resultados promissores é a inoculação com fungos micorrízicos arbusculares (FMA) durante o processo de aclimatação das mudas. Assim, o objetivo deste trabalho foi promover a melhoria do processo de produção de mudas através de embriogênese somática associada a inoculação com fungos micorrízicos arbusculares. Para a produção dos clones, plântulas foram utilizadas quando apresentaram quatro pares de folhas (clone 1 “Frutificação vermelha Catucaí” e clone 2 “Acauã”) produzidos e desenvolvidos em biorreatores “embriogênese somática” e quando levadas para o viveiro inoculadas com Rhizophagus clarus, Gigaspora margarita e Acaulospora mellea, a mistura de R. clarus e G. margarita e a mistura de R. clarus, G. margarita e A. mellea. Após seis meses foram avaliados os parâmetros agronômicos, teores de nutrientes foliar e a colonização micorrizica nas raízes. Os clones se comportaram diferentemente quando inoculados com o FMAs, sendo que o clone 1, o que apresentou melhor desenvolvimento no viveiro determinadas pelos parâmetros agronômicos, sendo indicada na produção de mudas clonais vigorosas qu, ando associado a inoculação com fungos micorrízicos arbusculares.

ABSTRACT The production of Coffea arabica L. clone seedlings through the somatic embryogenesis technique is one of the alternatives of greatest demand for coffee producers. However, clones can face difficulties related to acclimatization carried out under greenhouse conditions, which can increase the production costs. A tested alternative with promising results is inoculation with arbuscular mycorrhizal fungi (AMF) during the seedling acclimatization process. Thus, this study aimed to promote the improvement of the seedling production process through somatic embryogenesis associated with inoculation with AMF. For the production of the clones, seedlings were used in the phase when they presented four pairs of leaves (Clone 1 “Fruiting red Catucaí” and Clone 2 “Acauã”), using “somatic embryogenesis” bioreactors, followed by inoculation with Rhizophagus clarus, Gigaspora margarita and Acaulospora mellea, a mixture of R. clarus and G. margarita and a mixture of R. clarus, G. margarita and A. mellea. After six months, agronomic parameters, leaf nutrient contents and root mycorrhizal colonization were evaluated. The studied clones behaved differently when inoculated with AMFs. Clone 1 showed the best development in the greenhouse, which was determined by the agronomic parameters. Thus, Clone 1 is indicated for the production of vigorous seedlings when associated with inoculation with AMFs.

RESUMO Sistemas integrados de produção agropecuária (SIPA) com consórcios na fase pastagem promovem alterações na dinâmica de atributos dos solos, entre eles a atividade enzimática. Objetivou-se avaliar as atividades microbiana e enzimática do solo, após implantação de SIPA com aumento da diversidade de plantas na fase pastagem. O estudo consistiu no cultivo de soja na safra e pasto com diferentes níveis de diversidade na safrinha: muito baixa - Urochloa brizantha cv. BRS Paiaguás cultivado solteiro sem entrada de animais; baixa - Paiaguás em cultivo solteiro; média - Paiaguás e feijão caupi (Vigna unguiculata); alta - Paiaguás, feijão caupi e niger (Guizotia abyssinica); muito alta - Paiaguás, feijão caupi, niger, trigo mourisco (Fogopyrum esculentum) e nabo forrageiro (Raphanus sativus). A introdução de plantas de diferentes famílias, associadas ao pastejo, afetaram positivamente as atividades enzimáticas da fosfatase ácida, β-glicosidase e urease. Em relação aos atributos carbono da biomassa microbiana e respiração basal, não houve efeito dos tratamentos. Portanto, dentre os atributos bioquímicos do solo avaliados, as atividades de algumas enzimas do solo foram mais sensíveis em demonstrar, em curto período de tempo, os efeitos positivos do aumento da diversidade de plantas na fase de pastagem do SIPA.

ABSTRACT Integrated crop-livestock systems (ICLS) intercropped in the pasture phase promote alterations in the dynamics of soil attributes, among them the enzymatic activity. This study aimed to evaluate soil enzymatic and microbial activities, following the implementation of ICLS with increased plant diversity during the pasture phase. The study consisted of soybean cultivation at season and pasture with different diversity levels in the off-season: very low - monocropped Urochloa brizantha cv. BRS Paiaguás with no animal entry; low - monocropped Paiaguás; medium - Paiaguás and cowpea bean (Vigna unguiculata); high - Paiaguás, cowpea bean and niger (Guizotia abyssinica); very high - Paiaguás, cowpea bean, niger, buckwheat (Fogopyrum esculentum) and forage turnip (Raphanus sativus). The introduction of plants from different families, associated to grazing, positively affected the enzymatic activities of acid phosphatase, β-glucosidase and urease. In relation to microbial biomass carbon and basal respiration, there were no effects from the treatments. Therefore, among the evaluated biochemical soil attributes, the activities of some soil enzymes were more sensitive in demonstrating, in the short term, the positive effects of the increased plant variety in the ICLS pasture phase.

ABSTRACT The implementation of conservationist systems that improve soil properties and reduce the impacts of the conversion of native areas is fundamental for feasible agricultural exploitation. This study aimed to evaluate the impact on soil biological properties caused by the conversion of murundus fields into agricultural systems and verify the ability of the no-tillage conservation system to recover these properties over the years. Treatments consisted of three agricultural areas subjected to the same management (no-tillage), in a chronosequence (7, 11, and 14 years of conversion) and a reference area (murundus field). To evaluate soil quality, we analyzed total soil organic carbon, microbial biomass carbon, soil basal respiration, metabolic and microbial quotients, and acid phosphatase activities, as well as the potential functionality of soil bacterial communities and the modifications in their genetic structure. The conversion of murundus field into agricultural systems negatively impacted soil biological properties, with expressive reduction in soil organic carbon content and microbial biomass carbon. The periods of adoption of the conservationist system (no-tillage) were not enough to recover the biological properties and/or to reverse the changes observed in the genetic structure of the soil bacterial communities of the managed areas, although stabilization trends were observed in the agricultural systems over the years.

RESUMO Os benefícios da micorrização ocorrem com o crescimento das hifas nas raízes colonizadas, promovendo uma ampliação da superfície de contato, aumento a absorção de água e nutrientes das raízes, facilitando crescimento inicial.Objetivou-se avaliar o efeito da inoculação fungo micorrizico arbuscular Rhizophagus clarus sobre o desenvolvimento inicial e a resposta nutricional de seis genótipos de Coffea arabica L. Foram utilizados seis genótipos de Coffea arabica L. (MGS Aranãs, H 29-1-8-5, Catuai vermelho IAC 144, Catiguá MG2, Paraíso H 419-1) com fungo micorrizico arbuscularFMA: Rhizophagus clarus e sem aplicação do fungo com cinco repetições. Para produção das mudas de café, sementes foram colocadas para germinar em bandeijas plásticas com areia estéril. Após a germinação 10 mudas de cada genótipo foram transferidas para tubos de polietileno de 0,120 dm3com substrato. Nesse momento procedeu-se a inoculação de cinco mudas de cada genótipo com o FMA R. clarus. Quando as mudas de cafeeiro com e sem inoculação com o FMA apresentaram seis pares de folhas foram transplantadas para vasos de 13 litros, contendo solo (Latossolo Vermelho Amarelo Distrófico) esterilizado. A inoculação favoreceu o crescimento inicial das plantas de café e sua intensidade variou de acordo com os genótipos. Dos seis genótipos utilizados H 29-1-8-5, Catuai Vermelho IAC 144 e Catiguá MG 2 foram os que apresentaram maiores massa seca da parte aérea, massa seca das raízes, massa seca total e acúmulo do nutriente P, em relação ao MGS Aranãs, Paraiso H 419-1 e o IPR 100, sendo os mais promissores para serem inoculadas com fungo micorrízico arbuscular.

ABSTRACT The benefits of mycorrhization occur with the growth of hyphae in colonized roots by promoting an increase of the contact surface which improves the initial growth due to a better absorption of water and nutrients. The objective was to evaluate the effect of arbuscular mycorrhizal fungus Rhizophagus clarus inoculation over the initial development and nutritional response of six genotypes of Coffea arabica L. Six genotypes of Coffea arabica L. were used (MGS Aranas, H29-1-8-5, Red Catuai IAC 144, IPR 100, Catigua MG2, Paraíso H 419-1) and with arbuscular mycorrhizal fungus - AMF: Rhizophagus clarus and without the application of the fungus. For the production of coffee seedlings, seeds were placed to germinate in plastic trays with sterile sand. After germination, 10 seedlings of each genotype were transferred to 0.120 dm3 polyethylene tubes with substrate. Then the inoculation of five seedlings of each genotype with the AMF R. Clarus was performed. When the seedlings with and without inoculation with the AMF presented six pairs of leaves they were transplanted to 13-liter pots containing soil (Dystrophic red-yellow latosol). The inoculation favored the initial growth of the coffee plants and its intensity varied according to the genotypes. The genotypes H 29-1-8-5, Red Catuai IAC 144 and Catigua MG 2 were the ones that presented higher shoot dry mass, root dry mass, total dry mass and accumulation of P, in relation to MGS aranãs, Paraiso H 419-1 and IPR 100, so they are the most promising to be inoculated with the arbuscular mycorrhizal fungus.

Resumo: O objetivo deste trabalho foi avaliar o efeito do uso de escória de siderurgia como corretivo da acidez do solo e de fungos micorrízicos associados à adubação fosfatada em plantas de milho. O trabalho foi conduzido em casa de vegetação, tendo-se utilizado vasos com 3 kg de Latossolo Vermelho distrófico, em arranjo fatorial 4x5x2, com quatro tratamentos corretivos da acidez (C1, correção com calcário dolomítico na dosagem de 4 Mg ha-1; C2, correção com escória de siderurgia de aciaria na dosagem de 4 Mg ha-1; C3, correção com a mistura 1:1 de 2 Mg ha-1 de calcário dolomítico e 2 Mg ha-1 de escória; e C4, controle, sem correção de pH), cinco doses de fósforo (0, 42, 95, 213 e 480 mg dm-3), e presença ou ausência de dois fungos micorrízicos arbusculares (Rhizophagus clarus e Gigaspora margarita), com cinco repetições. A escória foi eficiente em corrigir o pH do solo e fornecer Ca e Mg para as plantas; portanto, pode substituir o calcário. A inoculação com R. clarus e G. margarita, associada às doses de 42, 95 e 213 mg dm-3 de P, promoveu melhoras no desenvolvimento de plantas de milho após 45 dias, tendo resultado em maiores altura, diâmetro do colo, área foliar e matéria seca das raízes e da parte aérea das plantas.

Abstract: The objective of this work was to evaluate the effect of the use of steel slag as a soil acidity corrective and of mycorrhizal fungi associated with phosphate fertilization on corn plants. The study was performed in a greenhouse, using 3-kg pots with a Typic Haplorthox, in a 4x5x2 factorial arrangement, with four acidity correction treatments (C1, correction with dolomitic limestone at a dose of 4 Mg ha-1; C2, correction with steel slag at a dose of 4 Mg ha-1; C3, correction with a 1:1 mixture of 2 Mg ha-1 dolomitic limestone and 2 Mg ha-1 steel slag; and C4, control, without pH correction), five phosphorus doses (0, 42, 95, 213, and 480 mg dm-3), and the presence or absence of two arbuscular mycorrhizal fungi (Rhizophagus clarus and Gigaspora margarita), with five replicates. Steel slag was efficient in correcting soil pH and providing Ca and Mg for the plants; therefore, it could replace limestone. The inoculation with R. clarus and G. margarita, associated with P doses of 42, 95, and 213 mg dm-3, improved the development of corn plants after 45 days, resulting in greater plant height, stem diameter, leaf area, and shoot and root dry matter.

RESUMO A estrutura é uma das propriedades mais importantes do solo, definida pelo arranjo das partículas e do espaço poroso formando agregados. Dentre os fatores biológicos que influenciam a formação e estabilização dos agregados no solo, destacam-se os fungos micorrízicos arbusculares (FMAs) através das hifas extrarradiculares e produção de glomalina. Nesse contexto, o objetivo desse estudo foi avaliar diferentes FMAs (Acaulospora colombiana, Acaulospora longula, Acaulospora morrowiae, Paraglomus occultum e Gigaspora margarita) associadas com Urochloa brizantha (A. Rich.) Stapf na estabilidade de agregados do solo. O estudo foi conduzido em delineamento inteiramente casualizado, utilizando Oxisol e areia lavada 2:1 (v/v) autoclavada, com sete tratamentos: cinco FMAs; tratamentos com plantas sem inoculação e com apenas o solo, com 5 repetições. O experimento foi conduzido durante 180 dias, avaliando: comprimento do micélio total (CMT); produção de proteína do solo relacionada à glomalina facilmente extraível (PSRG) no solo e nas classes de agregados; estabilidade dos agregados a seco e imersos em água, através do diâmetro médio geométrico (DMG) e diâmetro médio ponderado (DMP) dos agregados; e o índice de estabilidade de agregados (IEA). Observou-se que a inoculação favoreceu a agregação do solo com destaque para A. colombiana, que apresentou o maior DMG, CMT e produção de PSRG no agregados Ø>2,0mm e para. A. colombiana e A. morrowiae nos agregados com Ø<0,105mm, quando comparadas ao tratamento sem inoculação. Esses resultados mostram que há distinção dos efeitos dos diferentes FMAs no processo de formação e estabilidade dos agregados do solo.

ABSTRACT Soil structure, which is defined by the arrangement of the particles and the porous space forming aggregates, is one of the most important properties of the soil. Among the biological factors that influence the formation and stabilization of soil aggregates, arbuscular mycorrhizal fungi (AMF) are distinguished due to extrarradicular hyphae and glomalin production. In this context, the objective of this study was to evaluate different AMF (Acaulospora colombiana, Acaulospora longula, Acaulospora morrowiae, Paraglomus occultum and Gigaspora margarita) associated with Urochloa brizantha (A. Rich.) Stapf on soil aggregate stability. The study was conducted in a completely randomized design, using an Oxisol and autoclaved sand 2:1 (v/v), with seven treatments: five AMF; and treatments with plants without inoculation and with only the soil, with 5 replicates. The experiment was conducted during 180 days and the following variables were evaluated: mycelium total length (TML); production of easily extractable glomalin-related soil protein (GRSP) in the soil and aggregate classes; stability of the dry and immersed in water aggregates through the mean geometric diameter (MGD) and the mean weighted diameter (MWD) of aggregates; and the soil aggregate stability index (ASI). It was observed that the inoculation favored soil aggregation, with a high incidence of A. colombiana, which presented the highest MGD, TML and GRSP production in the aggregates with Ø>2.0mm and for A. colombiana and A. morrowiae in the aggregates with Ø<0.105 mm, when compared to the treatment without inoculation. These results show that there is a distinction between the effects of different AMF on the formation and stability of soil aggregates.

Resumo: O objetivo deste trabalho foi avaliar as alterações na qualidade do solo devido a diferentes tempos de adoção do sistema plantio direto em campos de murundus convertidos para agricultura, bem como identificar quais seriam os melhores indicadores para explicar essas alterações. O estudo foi realizado em Plintossolo Háplico, no Município de Portelândia, no Estado de Goiás. Os tratamentos consistiram de diferentes épocas de conversão e adoção do sistema plantio direto - 8, 12 e 17 anos - e de área nativa entre murundus e no topo dos murundus (área de referência). Após 17 anos da adoção de plantio direto, houve incremento de carbono e nitrogênio orgânicos, assim como das suas frações particuladas em relação à área de referência. Os atributos microbiológicos alcançaram valores superiores no plantio direto de 17 anos, em comparação à área nativa. Para a agregação do solo, 12 anos de adoção do plantio direto foram suficientes para mostrar incremento nessa variável. Os principais atributos para uso como indicadores da qualidade do solo são o carbono da biomassa microbiana, o índice de manejo de carbono e o quociente microbiano.

Abstract: The objective of this work was to evaluate changes in soil quality due to different times of adoption of the no-tillage system in “murundu” (mound) fields converted to agriculture, as well as to identify the best indicators to explain these changes. The study was carried out on a Plinthic Altisol, in the municipality of Portelândia, in the state of Goiás, Brazil. The treatments consisted of different times of conversion and of adoption of the no-tillage system - 8, 12, and 17 years - and of native area between the mounds and on top of the mounds (reference area). After 17 years of the adoption of no-tillage, there was an increase in organic carbon and nitrogen, as well as in their particulate fractions in relation to the reference area. The microbiological attributes showed greater values in the 17-year no-tillage period compared with the native area. For soil aggregation, 12 years of adoption of the no-tillage system were enough to show an increase in this variable. The main attributes to be used as soil quality indicators are microbial biomass carbon, the carbon management index, and the microbial quotient.

RESUMO Fungos micorrízicos arbusculares (FMA) podem apresentar comportamentos distintos, quando associados à mesma espécie de planta hospedeira, sendo necessário compreender sua ecologia, visando a otimizar o seu manejo e manutenção em banco de germoplama. Objetivou-se avaliar diferentes FMA associados a Urochloa brizantha (A. Rich.) Stapf, analisando-se o tempo de estabelecimento da simbiose, multiplicação de esporos e produção de proteína do solo relacionada a glomalina. O experimento foi conduzido em delineamento inteiramente casualizado, com arranjo 6 x 5 (cinco espécies de FMA, tratamento sem inoculação e cinco épocas de avaliação). Analisaram-se o crescimento das plantas, multiplicação de esporos, colonização micorrízica e produção de glomalina. A maior multiplicação de esporos ocorreu para Acaulospora longula e A. colombiana, apresentando maior colonização micorrízica aos 76 dias. A inoculação favoreceu o crescimento das raízes de U. brizantha a partir de 15 dias, altura das plantas e massa seca das raízes aos 60 dias e massa seca da parte áerea aos 90 dias, com destaque para espécies de Acaulospora. A inoculação com A. colombiana, A. longula e Paraglomus occultum promoveu incremento de glomalina aos 120 dias. Gigaspora margarita e P. occultum não atingiram a máxima colonização e multiplicação dos esporos, indicando ser necessário um período maior que 120 dias de cultivo dos FMA.

ABSTRACT Arbuscular mycorrhizal fungi (AMF) may exhibit distinct behaviors when associated with the same species of host plant, being necessary to understand their ecology, in order to optimize their management and maintenance in germplasm bank. This study aimed to evaluate different AMF associated with Urochloa brizantha (A. Rich.) Stapf by analyzing the symbiosis establishment time, spore multiplication and production of glomalin-related soil protein. The experiment was carried out in a completely randomized design, in a 6 x 5 arrangement (five AMF species, non-inoculated control treatment and five evaluation times). The following aspects were analyzed: plant growth, spore multiplication, mycorrhizal colonization and glomalin production. The highest number of spores occurred for Acaulospora longula and A. colombiana, exhibiting the highest mycorrhizal colonization at 76 days. The inoculation favored the root growth of U. brizantha at 15 days of cultivation, plant height and root dry matter at 60 days and shoot dry matter at 90 days, especially for the Acaulospora species. The inoculation with A. colombiana, A. longula and Paraglomus occultum resulted in increased glomalin at 120 days. Gigaspora margarita and P. occultum did not reach the maximum colonization and spore multiplication, indicating that a period of time longer than 120 days of cultivation is necessary.

Resumo: O objetivo deste trabalho foi avaliar as propriedades físicas e biológicas em um sistema de integração lavoura-pecuária (ILP), com ou sem pastejo, em diferentes safras. O experimento foi realizado no bioma Cerrado, no Brasil, em um Latossolo Vermelho distroférrico típico. Os tratamentos consistiram de áreas de pastejo (Urochloa ruziziensis) a 0,25, 0,35 e 0,45 m de altura (com cultivo de soja após o pastejo) e de áreas sem pastejo. O sistema ILP não teve efeitos negativos sobre densidade do solo, porosidade total, macroporosidade e microporosidade. Após a implementação do sistema ILP, os valores de densidade do solo diminuíram e os de macroporosidade aumentaram, nas áreas pastejadas e não pastejadas. No entanto, após três anos, a densidade e a macroporosidade foram reestabelecidas a valores similares aos anteriores à implementação do sistema ILP. A resistência do solo à penetração foi maior no sistema ILP, principalmente à profundidade de 0,00-0,05 m do solo. Após quatro anos, o sistema ILP promoveu o aumento do C e do N da biomassa microbiana e a redução do quociente metabólico. O carbono da biomassa microbiana e o quociente metabólico relacionaram-se ao diâmetro médio ponderado. Os benefícios do sistema ILP às propriedades físicas e biológicas do solo estão associados à implementação adequada do sistema ILP, à altura apropriada de pastejo (0,35 m) e à manutenção da cobertura do solo.

Abstract: The objective of this work was to evaluate the soil physical and biological properties in an integrated crop-livestock system (ICLS), with or without cattle grazing, in different seasons. The experiment was carried out in the Cerrado biome, in Brazil, in a Rhodic Eutrudox. The treatments consisted of grazing areas (Urochloa ruziziensis) at 0.25, 0.35, and 0.45 m heights (with soybean cultivation after grazing) and of nongrazed areas. The ICLS had no negative effects on soil bulk density, total porosity, macroporosity, and microporosity. After ICLS implementation, the values of soil bulk density decreased, and those of soil macroporosity increased, in the grazed and nongrazed areas. However, after three years, bulk density and macroporosity were reestablished to values similar to those before ICLS implementation. Soil penetration resistance was higher in the ICLS, mainly at 0.00-0.05 m soil depth. After four years, ICLS promoted the increase of microbial biomass C and N and the reduction of the metabolic quotient. The microbial biomass carbon and the metabolic quotient were related to the weighted mean diameter. ICLS benefits to soil physical and biological properties are associated with adequate ICLS implementation, adequate grazing height (0.35 m), and maintenance of soil cover.

Resumo: O objetivo deste trabalho foi avaliar a qualidade do solo e sua relação com a produtividade de soja (Glycine max) em sistema de integração lavoura-pecuária (ILP), com consórcio entre gramíneas e leguminosas na fase pastagem. O experimento foi realizado no Estado de Mato Grosso, em um Latossolo Vermelho distrófico, em que gramíneas (Megathyrsus maximus 'BRS Tamani' e Urochloa brizantha 'BRS Piatã'), consorciadas com feijão-caupi (Vigna unguiculata 'BRS Tumucumaque') e feijão-guandu (Cajanus cajan 'BRS Mandarim'), foram cultivadas após a colheita da soja. Um delineamento experimental de blocos ao acaso foi utilizado com três repetições, em arranjo de parcelas subdivididas, em que as gramíneas foram consideradas como parcelas, e as leguminosas, como subparcelas. Os consórcios com leguminosas proporcionaram incrementos dos estoques de C e N total. Os consórcios causaram o aumento de C e N da biomassa microbiana, enquanto os cultivos solteiros contribuíram para o estresse da microbiota do solo. A atividade da enzima urease foi sensível às alterações de manejo em curto prazo, porém a fosfatase ácida e a β-glucosidase foram indicadores pouco sensíveis. A qualidade do solo é elevada com os consórcios entre gramíneas e leguminosas, com efeitos positivos sobre a produtividade de grãos de soja.

Abstract: The objective of this work was to evaluate the quality of the soil and its relation with soybean (Glycine max) yield in an integrated crop-livestock system (ICLS), with intercropping between grasses and legumes in the pasture phase. The experiment was carried out in the state of Mato Grosso, Brazil, on a dystrophic Oxisol, in which grasses (Megathyrsus maximus 'BRS Tamani' and Urochloa brizantha 'BRS Piatã'), intercropped with cowpea (Vigna unguiculata 'BRS Tumucumaque') and pigeon pea (Cajanus cajan 'BRS Mandarim'), were cultivated after soybean harvest. A randomized complete block design was used, with three replicates, in a split-plot arrangement, in which grasses were considered as plots, and legumes as subplots. Legume intercrops provided increases of C and total N stocks. The intercrops caused the increase of C and N of the microbial biomass, whereas the single cultures contributed to stress in the soil microbiota. The activity of the urease enzyme was sensitive to management changes in the short term, but acid phosphatase and β-glucosidase were poorly sensitive indicators. Soil quality is high with intercropping between grasses and legumes, with positive effects on soybean grain yield.

Resumo: O objetivo deste trabalho foi avaliar a influência de fungos micorrízicos arbusculares (FMA) na acumulação de biomassa da parte aérea e da raiz e nos teores de nutrientes de Urochloa decumbens cultivada em solos com diferentes densidades. O delineamento experimental foi em blocos ao acaso, em arranjo fatorial 4x2: quatro densidades do solo (1,0, 1,2, 1,4 e 1,6 kg dm-3) com e sem inoculação de FMA, com quatro repetições. Determinaram-se a acumulação de biomassa (massa de matéria seca da parte aérea e da raiz) e os teores de macro e micronutrientes em U. decumbens, nas diferentes densidades do solo. Avaliou-se a colonização micorrízica das plantas, e determinou-se o número de esporos micorrízicos presentes no solo. A acumulação de biomassa da parte aérea e da raiz e o conteúdo de macro e micronutrientes, bem como o número de esporos micorrízicos no solo, foram afetados negativamente pelo aumento na densidade do solo. Apenas a biomassa de raízes apresentou incremento com a inoculação de FMA. Não houve interação da densidade do solo e da inoculação na acumulação de biomassa na parte aérea e na raiz. Os fungos micorrízicos arbusculares influenciam a acumulação de biomassa nas raízes e de N e Ca na parte aérea de Urochloa decumbens mesmo nas densidades mais altas.

Abstract: The objective of this work was to evaluate the influence of arbuscular mycorrhizal fungi (AMF) on the accumulation of shoot and root biomass and on the nutrient contents of Urochloa decumbens grown in soils with different densities. The experiment was carried out in a randomized complete block design, in a 4x2 factorial arrangement: four soil densities (1.0, 1.2, 1.4, and 1.6 kg dm-3) with and without inoculation of AMF, with four replicates. The biomass accumulation (dry matter weight of shoot and roots) and macro- and micronutrient contents of U. decumbens were determined at different soil densities. The mycorrhizal colonization of the plants was evaluated, and the number of mycorrhizal spores present in the soil was determined. The biomass accumulation of shoot and roots and macro- and micronutrient contents, as well as the number of mycorrhizal spores in the soil, were negatively affected by the increase in soil density. Only root biomass increased with AMF inoculation. There was no interaction between soil density and inoculation for shoot and root biomass accumulation. Arbuscular mycorrhizal fungi influence the accumulation of biomass in the roots and of N and Ca contents in the shoots of Urochloa decumbens even at the highest soil densities.