RESUMO O objetivo deste trabalho foi avaliar o crescimento e a micorrização de mudas de angico (Anadenanthera peregrina (Vell.) Brenan) e braúna (Melanoxylon brauna Schott) em casa de vegetação a partir de inoculante com comunidade de fungos micorrízicos arbusculares (FMAs) selecionados ou coletada em campo, em substrato formulado e comercial. Cada espécie fez parte de um experimento, instalado em delineamento inteiramente casualizado em esquema fatorial 2x4, sendo dois tratamentos de substratos, quatro de inoculação e quatro repetições de 12 mudas cada, totalizando 384 mudas por experimento. Os substratos utilizados foram: RAD - composto pela mistura de 30% de composto orgânico, 30% de subsolo (argiloso), 30% de solo arenoso e 10% de fosfato de rocha; e SC - substrato comercial composto pela mistura de vermiculita expandida, turfa, carvão, macro e micronutrientes; e quatro tratamentos: T1 - controle; T2 - controle adubado; T3 - mistura de fungos selecionados; e T4 - mistura de fungos nativos. Aos 100 dias após a semeadura para angico e 180 dias para braúna, foram realizadas medições de altura e diâmetro do coleto das mudas e determinados: área foliar (AF), matéria seca da parte aérea (MSPA) e sistema radicular (MSSR), número esporos de FMAs e colonização micorrízica. Para o angico, as mudas produzidas no substrato RAD proporcionaram maiores valores de altura, diâmetro, MSPA, AF, MSSR, além de maior eficiência da inoculação e esporulação no substrato. As mudas de angico inoculadas apresentaram maior altura e AF quando comparadas às não inoculadas, em ambos os substratos. Para braúna, o tipo de substrato influenciou apenas o diâmetro, cujo RAD promoveu maior crescimento. No substrato RAD, a inoculação com FMAs selecionados (T3) proporcionou maiores incrementos em altura e diâmetro. No substrato SC todas as mudas produzidas no tratamento T2 (adubado e não inoculado) morreram, enquanto os tratamentos de inoculação promoveram aumentos na produção de AF, MSPA, e MSSR. Recomenda-se a produção de mudas de angico com substrato RAD inoculadas com comunidade de FMAs nativos coletada em campo. Para braúna, sugerem-se estudos utilizando outras técnicas de produção aliadas à inoculação com FMAs. Anadenanthera Vell. Vell (Vell. Brenan Melanoxylon Schott (FMAs campo experimento 2x4 x 1 cada 38 30 orgânico argiloso, argiloso , (argiloso) 10 rocha expandida turfa carvão micronutrientes T adubado 18 determinados (AF) MSPA (MSPA MSSR (MSSR) micorrízica (T3 inoculado morreram Recomendase Recomenda se sugeremse sugerem (Vell 2x 3 (argiloso (AF (MSSR (T

ABSTRACT This study aimed to assess the growth and mycorrhization of greenhouse-grown angico (Anadenanthera peregrina (Vell.) Brenan) and brauna (Melanoxylon brauna Schott) seedlings based on inoculation with a community of selected or field-collected arbuscular mycorrhizal fungi (AMF), in formulated and commercial substrate. Each species corresponded to one experiment, conducted in a completely randomized design and 2x4 factorial scheme, consisting of two substrates, four inoculation treatments and four repetitions of 12 seedlings each, totaling 384 seedlings per experiment. The substrates used were: DAR – mixture of 30% organic compost, 30% subsoil (clay), 30% sandy soil and 10% rock phosphate; and CS - commercial substrate consisting of expanded vermiculite, peat, charcoal, macro and micronutrients; and four treatments: T1 - control; T2 – fertilized control; T3 – mixture of selected fungi; and T4 – mixture of native fungi. At 100 days after sowing (DAS) for angico and 180 DAS for brauna, seedling height and diameter were measured and leaf area (LA), shoot (SDW) and root dry weight (RDW), number of AMF spores and mycorrhizal colonization were determined. Angico seedlings grown in DAR obtained the highest diameter, height, SDW, RDW and LA values, as well as greater inoculation efficiency, LA, RDW, as well as greater inoculation efficiency and sporulation in this substrate. In both substrates, inoculated angico seedlings were taller and had a larger LA than their noninoculated counterparts. In brauna, the type of substrate only influenced seedling diameter, with DAR promoting greater growth. In DAR substrate, inoculation with selected AMF (T3) resulted in greater seedling height and diameter. In CS, all the seedlings produced in T2 (fertilized and noninoculated) died, whereas the inoculation treatments increased LA, SDW and RDW. It is recommended that angico seedlings grown in DAR be inoculated with native AMF collected in the field. For brauna, further research is needed using other production techniques combined with AMF inoculation. greenhousegrown greenhouse Anadenanthera Vell. Vell (Vell. Brenan Melanoxylon Schott fieldcollected field AMF, , (AMF) experiment x 2x scheme 1 each 38 30 compost clay, clay (clay) 10 phosphate vermiculite peat charcoal micronutrients T control (DAS 18 (LA) (SDW (RDW) determined values counterparts (T3 died (Vell (AMF 3 (clay (LA (RDW (T

Resumo A erosão hídrica é uma das principais causas da degradação das terras agricultáveis brasileiras, levando à diminuição da produtividade das culturas e à acidificação do solo, prejudicando sua capacidade de armazenar carbono, nutrientes e água. O manejo inadequado do solo é um dos principais responsáveis por esse tipo de degradação. A identificação da intensidade da erosão pode ser feita por meio da utilização de atributos indicadores que são altamente sensíveis as mudanças no ambiente edáfico. O estudo teve como objetivos: i) analisar os atributos físicos e químicos do solo em áreas de voçorocas com diferentes graus de degradação/estabilização; e ii) verificar a viabilidade de utilização desses atributos como indicadores de recuperação ambiental. O estudo foi realizado em quatro áreas com diferentes graus de formação de voçorocas: a) inicial, intermédia, madura e senil. As amostras foram coletadas nas faces externa e interna de cada voçoroca no final da estação seca. Entre os atributos físicos avaliados, a densidade do solo e a porosidade total foram os mais significativamente alterados. A avaliação dos microagregados permitiu conhecer a qualidade do solo através de frações como a argila dispersável em água, a argila refloculável em água e a argila não dispersível em água. O carbono total, o nitrogênio total e a relação C/N elucidaram a dinâmica da perda de solo e de nutrientes em diferentes fases dos processos de formação e estabilização da erosão, com valores mais baixos observados na face interna das voçorocas em comparação a externa. Observou-se que a vegetação influenciou os resultados dos atributos físicos e químicos. No geral, os valores tenderam ao equilíbrio entre as faces na voçoroca SE, indicando maior estabilização. Com base nesses resultados, os atributos avaliados podem servir como indicadores de qualidade do solo, pois são mais eficientes e sensíveis em expressar a recuperação da qualidade física e química do solo, fornecendo informações valiosas para o monitoramento de processos de degradação e para a prevenção, controle e recuperação de voçorocas no Bioma Mata Atlântica. brasileiras edáfico objetivos i degradação/estabilização degradaçãoestabilização ii ambiental inicial intermédia senil seca alterados CN C N Observouse Observou se geral SE prevenção Atlântica

Abstract Water erosion is one of the primary causes of agricultural soil degradation in Brazil, leading to diminished crop productivity and soil acidification, thereby impairing its ability to store carbon, nutrients, and water. Identifying the intensity of erosion can be achieved by utilizing indicator attributes that are highly sensitive to changes in the edaphic environment. The study analyzed the physical and chemical attributes of soil in areas with gullies exhibiting varying degrees of degradation/stabilization. The study was conducted across four areas with varying degrees of gully formation: a) initial, intermediate, mature, and senile. Samples were collected from both the external and internal sides of each gully at the end of the dry season. Among the physical attributes assessed, soil density and total porosity were found to be the most significantly altered. Evaluation of microaggregates provided insights into soil quality through fractions including water-dispersible clay, water-reflocculable clay, and non-water-dispersible clay. Total carbon, total nitrogen, and the C/N ratio elucidated the dynamics of soil and nutrient loss across different stages of erosion formation and stabilization processes, with lower values observed on the internal side of the gullies compared to the exterior side. Vegetation was observed to influence the results of the physical and chemical attributes. Overall, the values tended towards equilibrium between the faces at the senile stage, indicating greater stabilization. Brazil acidification carbon nutrients water environment degradationstabilization degradation/stabilization a initial intermediate mature season assessed altered waterdispersible dispersible clay waterreflocculable reflocculable nonwaterdispersible non nitrogen CN C N processes Overall stage

ABSTRACT The benefits promoted by arbuscular mycorrhizal fungi (AMF) to forest species seedlings include higher growth rate, better nutrition, and higher survival rates. Inoculation with AMF may facilitate revegetation of degraded lands, although it depends on symbionts and environmental conditions, such as soil P availability. In this sense, the lack of information justifies the carrying out of studies of this nature. We investigated the dependence and responsiveness of two forest species native to the Atlantic Forest, Pseudobombax grandiflorum and Bauhinia forficata, to different AMF inocula (isolated AMF species, Dentiscutata heterogama, DH, Gigaspora margarita, GM, Rhizophagus clarus, RC, mixed inoculum with these former three AMF species, MI) compared to the uninoculated control (UC), combined with different P doses applied to the substrate (0, 24, 71, 213, and 650 mg kg-1), under greenhouse conditions. We evaluated root colonization, growth, and nutritional variables for Pseudobombax grandiflorum and Bauhinia forficata, 112 and 116 days after sowing with pre-germinated seeds, respectively. Native forest species exhibited different degrees of mycorrhizal dependence. The highest mycorrhizal dependence of P. grandiflorum seedlings was indicated by significant benefits, both growth and nutritional, promoted by innoculation treatments, under fertilization with the intermediate dose of P (213 mg kg-1). In fact, under this P dose, seedlings responded to a maximum increase in biomass in the GM treatment and maximum concentration of P and N in the shoots in the UC and DH treatments, respectively. The lowest mycorrhizal dependence of B. forficata seedlings was highlighted by significant growth benefits promoted by inoculation treatments under the lowest doses of P (24 or 71 mg kg-1). Under this P dose, we observed seedlings with maximum value of the root:shoot ratio in most of the types of inoculation and also higher values of biomass and height in the MI treatment. The responsiveness in terms of increase in growth and nutritional variables varied depending on the forest species, the dose of P applied to the substrate, and the AMF type of inoculum used. Root biomass and total dry biomass, mainly, should preferably be included in future studies with the same objective as the present study, as they were more relevant to point out the differences between treatments, in comparison with the variables associated with nutritional variables. (AMF rate nutrition rates lands conditions availability sense nature Forest isolated heterogama margarita clarus RC UC, , (UC) 0, 0 (0 24 213 65 kg1, kg1 kg 1 kg-1) colonization 11 pregerminated pre germinated seeds respectively (21 kg1. . fact B (2 7 rootshoot shoot used mainly study (UC ( 2 21 6 kg-1 kg-

ABSTRACT State parks are integral protection units created to protect ecosystems. However, anthropic activities may have been previously performed before their creation, forming transitional areas. Studies that evaluate the modifications of edaphic properties in these environments are scarce. The aim of this study was to evaluate the changes in soil properties and litter stock in areas of eucalyptus-forest ecotones. Litter stock (Stocklitter) and total soil organic carbon content and stock (TOCsoil), weighted mean diameter (MWD), origin of aggregates (biogenic or physicogenic) and respective content of total organic carbon (TOCBio and TOCPhy), total organic carbon (TOCAG), soil organic matter chemical fractions [fulvic acid (FAC), humic (HAC), and humin (HUMC)], and particulate, mineral-associated, free light and intra-aggregate light (POC, MAOC, FLFC, and ILFC) soil organic matter, fertility, and glomalin-related soil protein (GRSP) fractions were evaluated in aggregates (layer 0.00-0.10 m) in areas of eucalyptus-forest ecotone (Eco), preserved forest fragment (For), and eucalyptus plantation (Euc), in Nova Baden State Park, Lambari–MG. In the Euc and Eco areas, the highest Stocklitter content was found. Higher values of TOCsoil, TOCAG, GRSP, and MWD were observed in the Euc area. In the biogenic aggregates, the highest content of TOCBio, HAC, HUMC, POC, MAOC, FLFC, and ILFC was determined in detriment of the physicogenic ones. The dynamics of edaphic properties in the Eco area showed greater similarity with the For area than in the Euc area. In general, all vegetation covers contribute to the maintenance of soil quality. ecosystems However creation scarce eucalyptusforest ecotones (Stocklitter TOCsoil , (TOCsoil) MWD, (MWD) TOCBio TOCPhy, TOCPhy TOCPhy) TOCAG (TOCAG) fulvic FAC, FAC (FAC) HAC (HAC) HUMC (HUMC)] particulate mineralassociated, mineralassociated mineral associated, associated mineral-associated intraaggregate intra aggregate POC (POC MAOC FLFC fertility glomalinrelated glomalin related GRSP (GRSP layer 0.000.10 000010 0.00 0.10 0 00 10 0.00-0.1 m Eco, (Eco) For, (For) Euc, (Euc) Park LambariMG Lambari MG Lambari–MG found ones general quality (TOCsoil (MWD (TOCAG (FAC (HAC (HUMC) 000 0.000.1 00001 0.0 010 0.1 1 0.00-0. (Eco (For (Euc (HUMC 0.000. 0000 0. 01 0.00-0 0.000 0.00-

RESUMO Várias espécies lenhosas tropicais são altamente responsivas a fungos micorrízicos arbusculares (FMA) e dependem da simbiose para nutrição e sucesso no estabelecimento em campo. O objetivo deste estudo foi avaliar a resposta de Schinus terebinthifolius, uma espécie nativa da Mata Atlântica e Caatinga, à inoculação com três espécies de FMA (Dentiscutata heterogama, Gigaspora margarita e Rhizophagus clarus), individualmente ou misturadas, em diferentes níveis de adubação fosfatada (0, 71, 213 e 650 mg kg−1 de P). O experimento foi conduzido em vasos de 1 kg, seguindo um delineamento inteiramente casualizado com seis repetições por tratamento, para avaliar as características morfológicas e nutricionais, após 116 dias, incluindo diâmetro do colo, altura, biomassa e teor de P na parte aérea da planta. Nossos resultados evidenciaram que S. terebinthifolius foi altamente dependente de micorrizas e apresentou respostas diferentes dependendo da espécie de FMA. O maior acúmulo de biomassa total ocorreu quando foi utilizada uma mistura das três espécies de FMA, o que indicou sinergismo entre os fungos. De uma forma geral, a maior resposta positiva à inoculação foi observada em nível intermediário de P (213 mg kg−1), e embora a biomassa da parte aérea tenha sido reduzida nas doses intermediárias de P, foi observada uma compensação com um aumento na biomassa radicular. Esses resultados indicam complementaridade em oposição à redundância funcional das espécies de FMA e destacam a importância do uso de inóculo misto na produção de mudas de S. terebinthifolius para programas de revegetação.

ABSTRACT Several tropical woody species are highly responsive to arbuscular mycorrhizal fungi (AMF) and depend on their symbiosis for nutrition and successful establishment in the field. The objective of this study was to evaluate the response of Schinus terebinthifolius, a native species of the Brazilian Atlantic Forest and Caatinga, to inoculation with three AMF species (Dentiscutata heterogama, Gigaspora margarita, and Rhizophagus clarus), either individually or mixed, at different levels of phosphorus fertilization (0, 71, 213, and 650 mg kg−1 of P). We conducted the experiment in 1 kg pots, following a completely randomized design with six replicates per treatment, to evaluate morphological and nutritional traits after 116 days, including stem diameter, plant height, plant biomass, and shoot P content. Our results showed that S. terebinthifolius was highly dependent on mycorrhizae and presented different responses depending on the AMF species. The greatest total biomass accumulation occurred when a mixture of the three AMF species was used, which indicated synergism between the fungi. The highest overall positive response to inoculation were observed at an intermediate P level (213 mg kg−1), and although shoot biomass was reduced at the intermediate P doses, an increase in root biomass compensated for this. These results indicate complementarity as opposed to functional redundancy of the AMF species and highlight the importance of using a mixed inoculum in seedling production of S. terebinthifolius for revegetation programs.

RESUMO O objetivo deste estudo foi identificar as comunidades dos fungos micorrízicos arbusculares (FMAs) presentes em solos sob ecossistemas de silvipastagens, pastagens e mata de cerrado, além de avaliar a influência do sistema de uso do solo, textura do solo e da sazonalidade na dinâmica das comunidades destes fungos, no município de Alta Floresta D’Oeste - RO. As amostras de terra foram coletadas aleatoriamente na profundidade de 0 a 20 cm, em cada um dos ecossistemas em Julho/2010 (período seco) e Janeiro/2011 (período chuvoso). Após extraídos, os esporos foram contados e identificados. Estimou-se a densidade dos esporos e a densidade de cada espécie de FMA. Calcularam-se a frequência de ocorrência de cada espécie, o índice de diversidade de Shannon e o índice de diversidade de Simpson. Realizou-se uma análise multivariada de agrupamento baseado no número de indivíduos das espécies dos FMAs. Houve tendência de um maior número de esporos no ecossistema de mata de Cerrado independente da textura do solo ou da estação do ano, quando comparado as áreas de pastagem e silvipastagem. A espécie de Glomus macrocarpum apresentou 100% de frequência de ocorrência na estação chuvosa em ambas as texturas do solo. A influência da textura e da sazonalidade na composição e diversidade da comunidade dos FMAs foi mais expressiva no ecossistema de mata de Cerrado. O clima, a textura do solo, o manejo e o sistema de uso do solo afetam a composição e diversidade de espécies de FMAs.

ABSTRACT The objective of this study was to identify communities of arbuscular mycorrhizal fungi (AMF) in soils under pasture, silvopasture, and Cerrado forest ecosystems, and evaluate the effects of land use system, soil texture, and seasonality on the dynamics of AMF communities, in Alta Floresta D'Oeste, Rondônia, Brazil. Samples of the soil 0-20 cm layer were randomly collected in each ecosystem in July, 2010 (dry season) and January, 2011 (rainy season). Spores were extracted, counted, and identified. The spore density and density of each species of AMF were estimated. The frequency of occurrence, Shannon diversity index, and Simpson diversity index were calculated for each species. Multivariate clustering analysis was carried out, considering the number of AMF of each species. The results showed a trend of higher number of spores in the Cerrado forest ecosystem, regardless of the soil texture or season, when compared to pasture and silvopasture areas. The Glomus macrocarpum species presented 100% frequency of occurrence in the rainy season in both soil textures. The effects of texture and seasonality on the composition and diversity of AMF communities was more expressive in the Cerrado forest ecosystem. The climate, soil texture, and land use and management affected the composition and diversity of AMF species.

Understanding of the organomineral interactions in soil can elucidate the humic substances (HS) formation and the humification process. This study aimed to structurally characterize the humic acids (HA) formed in tropical soils with different pedogenesis degrees. The HA fraction was extracted from soil samples in the superficial horizons of an Inceptisol and a Mollisol in Rio de Janeiro state. The HA was characterized using spectroscopic techniques following by chemometric analyses: principal component analysis, descriptive analysis, and multivariate curve resolution. The results show that HA extracted from superficial horizon of Inceptisol and Mollisol are structurally different. The Inceptisol HA has a lower E4/E6 ratio than the Mollisol HA. The chemical groups show that most -CH groups belong to -CH2 and -CH3 and hydroxyls (-OH) for the Inceptisol HA, whereas the Mollisol HA predominantly contains aromatic C=C groups. The Inceptisol HA is mainly composed of CAlkyl-H,R and -C=O structures, whereas the Mollisol HA contains a higher quantity of CAlkyl-O,N, CAlkyl-O and CAromatic-H,R groups. The Inceptisol HA has a higher aliphatic content and hydrophobicity than the Mollisol HA. In Inceptisol, organic carbon stabilization can be facilitated by hydrophobic interactions, whereas in Mollisol, different interaction sites can stabilize proteinaceous compounds.

ABSTRACT Soil aggregates and their stability affect a wide range of soil properties. This study aimed to (a) verify whether biogenic aggregation provides higher macro- and microaggregate stabilization, and (b) evaluate whether biogenic aggregates are associated with higher labile organic carbon and glomalin contents. Three management systems were evaluated (permanent pasture, PP; no-tillage system, NT; and no-tillage + Brachiaria system, NT+B) as well as a reference area (Atlantic Forest biome vegetation, NF). According to their origin or formation pathway, the aggregates were separated, identified, and classified as biogenic (formed by biological processes) and physicogenic (resulting from chemical and physical actions). The PP system provided the greatest stabilization of the macroaggregates, regardless of the formation pathway, as reflected by a greater mean weight diameter (MWD). The PP system also influenced the degree of microaggregate stability by increasing the bond strength and reducing the dispersion of the clay fraction. Finally, the PP system elevated the contents of labile organic carbon (POXC), easily extractable glomalin (GRSP-EE), and total glomalin (GRSP-T) under both formation pathways. The NT+B system favored the stabilization of macroaggregates, especially in the subsurface soil layer, compared with the NT area. In the aggregates of the NT and NT+B areas, the highest values observed were for water-dispersible clay (WDC) and the lowest values observed were for non-dispersible clay (NDC), a pattern opposite to that observed in the aggregates of the PP and NF areas. In the biogenic aggregates of all areas, a high POXC content was quantified, and biogenic aggregation proportionally increased the values of MWD, GRSP-EE, and GRSP-T relative to physicogenic aggregation. The results showed that grain production systems, pasture systems, and non-anthropized environments differentially influenced aggregation and the concentrations of organic fractions associated with aggregate stability. This study highlights the need for future studies using these indicators to monitor the quality of soils, especially those with sandy texture, which are considered more fragile.

ABSTRACT: Reducing soil degradation and its impacts on the environment have been one of the main challenges of the 21st century, exacerbated by a direct link between increases in the human population and soil degradation that raises current and future food security concerns. Despite this, experiences worldwide reveal that degraded land restoration projects have either achieved little success or failed. Thus, understanding the underlying causes and devising appropriate restoration mechanisms is crucial. Soil amelioration using beneficial microorganisms, particularly arbuscular mycorrhizal fungi (AMF), is essential and pragmatic. Glomalin, a type of glycoprotein produced by arbuscular mycorrhizal fungi in the phylum Glomeromycota, contributes to the mitigation of soil degradation. Moreover, AMF and glomalin are highly correlated with other soil physico-chemical parameters and are sensitive to changes in the environment. As a result of this, they have been recommended for monitoring the recovery of degraded soil or stages of soil degradation. In this review, we discuss the role of AMF and glomalin in the restoration of degraded soils, including improvements to the soil structure and soil organic matter (SOM), microbial activity, reduction of fertility loss, bioremediation, and mitigation of the effects of drought and saline stress. We highlight the research gaps and discuss the prospects. This knowledge will improve our understanding of the ecological conduct of glomalin and AMF, stimulate future research, and be useful to sustainable restoration of degraded lands. Furthermore, we discussed the challenges and obstacles in the legislation and future perspectives on the production of inoculants based on AMF in Brazil.

Resumo A erosão hídrica é uma das principais formas de degradação do solo, causando danos econômicos, ambientais e sociais. O objetivo deste estudo foi avaliar o efeito de diferentes estágios de formação de voçorocas (inicial - IG; juvenil - JG; maduro - MG; e senil - SG) nos atributos químicos, matéria orgânica e microbiológicos do solo, utilizando uma floresta secundária (SF) e duas áreas de pastagem como referência no ambiente “Mar de Morros” do bioma Mata Atlântica brasileira. Amostras de solo (profundidade 0-0,05 m) foram coletadas no final das estações chuvosa e seca. As voçorocas em diferentes estágios de formação promoveram diminuição da fertilidade do solo e modificação dos atributos microbiológicos, principalmente quando comparados com a área de floresta secundária. Reduções de mais de 60% no carbono orgânico total (TOC), carbono orgânico oxidável (POXC), atividade da FDA, β-glicosidase, fosfatase ácida, C (MBC) e N (MBN) da biomassa microbiana, respiração basal do solo (BSR) e proteína do solo relacionada à glomalina (GRSP) foram observados em voçorocas nos estágios inicial (IG) e intermediário (JG e MG) quando comparados ao SF. Verificou-se que o efeito da erosão sobre os atributos químicos e microbiológicos do solo é mais intenso em voçorocas nos estágios inicial e intermediário em comparação com ao senil (SG). Usando a multivariada PCA, os atributos microbiológicos e químicos do solo discriminaram as voçorocas com distintos estágios de formação. Os atributos químicos, TOC, POXC, atividade FDA, β-glicosidase, fosfatase ácida, MBC and MBN, SBR e GRSP são bons indicadores para avaliar o processo de estabilização da erosão em voçorocas.

Abstract Water erosion is one of the main forms of soil degradation, causing economic, environmental, and social damage. This study evaluated the effects of different formation stages of gullies (initial - IG; juvenile- JG; mature - MG; and senile - SG) on the chemical, organic carbon and microbiological attributes of soil, using a secondary forest (SF) and two areas of pasture as references in the “Mar de Morros” environment of the Brazilian Atlantic Forest biome. Soil samples (depth 0-0.05 m) were collected at the end of the rainy and dry seasons. Gullies in different stages of formation promote a decrease in soil fertility and modification of microbiological attributes, particularly when compared with secondary forest areas. Reductions of over 60% in total organic carbon (TOC), oxidizable organic carbon (POXC), FDA activity, β-glycosidase, acid phosphatase, C and N from microbial biomass, basal soil respiration (BSR) and glomalin-related soil protein (GRSP) were observed in gullies in early (IG) and intermediate (JG and MG) stages when compared to SF. It was found that the effect of erosion on soil chemical and microbiological attributes is more intense in gullies in the initial and intermediate stages compared with those in the senile stage (SG). Using multivariate PCA, the microbiological and chemical attributes of the soil are discriminated between gullies with distinct formation stages. Chemical attributes, TOC, POXC, FDA activity, β-glycosidase, acid phosphatase, MBC and MBN, BSR, and GRSP are good indicators for evaluating the process of erosion stabilization in gullies.

Abstract Our study aimed to evaluate the influence of rubber tree plantations (Clones IAN 873 and FX 3864) on microbial activity, total organic carbon (TOC), and soils chemical attributes, using as reference pasture and secondary forest, in Rio de Janeiro. The plantations areas showed pH; Mg2+, Ca2+, K+ levels; sum of bases; base saturation, basal respiration; metabolic quotient; and arylsulfatase and FDA activities in the soil similar to or greater than the values found in the forest. In contrast, showed lower P and TOC levels; carbon and nitrogen in the microbial biomass; and β-glucosidase activity than of forest and pasture. Higher acid phosphatase and laccase enzymes activities was observed in the forest and plantations than in the pasture. Thus, we verified that the rubber tree plantations (Clones: IAN 873; FX 3864) maintain or improve the quality of some chemical and microbiological attributes of the soil regarding secondary forest and pasture.

Abstract This study aimed to evaluate enzyme activity, glomalin-related soil proteins (GRSP), soil chemical attributes, and total organic carbon (TOC) in two Agroforestry systems (AFS) (AFS-1 and AFS-2), in a traditional agriculture area (TA), and secondary forest (SF) area in Paraty (RJ). Soil samples (from 0 to 5 cm depth) were collected during the rainy and dry seasons. AFS improves and/or maintains soil chemical indicators based on pH increase, reduces aluminum saturation and maintains soil nutrient content (Ca, Mg and K), when compared with SF. The contribution of organic material and the biodiversity of the AFS provide the maintenance of the total organic carbon content of the soil. AFS maintain the activity of the enzymes protease, β-glucosidase, acid phosphatase, and total enzyme activity (FDA), and the production of glomalin-related soil protein at levels similar to those observed in SF, especially during the rainy season.

RESUMO Esse estudo avaliou a influência dos sistemas agroflorestais e da agricultura tradicional sobre os atributos físicos e biológicos do solo, utilizando como referência uma área de floresta nativa em Paraty, RJ. Foram analisados os teores do carbono orgânico total do solo e suas frações oxidáveis, a estabilidade dos agregados, além da atividade e os teores de carbono e nitrogênio da biomassa microbiana do solo, na camada de 0-5 cm, em duas épocas (seca e chuvosa) distintas. Os sistemas agroflorestais e a agricultura tradicional mantêm níveis elevados de carbono orgânico total e seu armazenamento em frações mais estáveis. Quando comparados à área de Floresta, esses sistemas proporcionam as mesmas condições para a agregação do solo. A biomassa microbiana foi mais responsiva as variações de manejo e sazonalidade. A implantação de sistemas agroflorestais contribui para a formação de uma matriz agrícola mais diversificada, promovendo melhorias na qualidade do solo e conexão com os remanescentes florestais próximos.

ABSTRACT In the present study, we evaluated the influence of agroforestry systems and traditional agriculture on the physical attributes and biologicals of soil, using as reference a native forest area in Paraty, RJ. Levels of total soil organic carbon, as well as oxidizable fractions and aggregate stability, were analyzed, in addition to the activity and carbon and nitrogen content in the soil microbial biomass, in the 0-5 cm layer, in two distinct seasons (dry and rainy seasons). The agroforestry systems and traditional agriculture maintain high levels of total organic carbon and its storage in more stable fractions. These systems provide the same conditions as those of the forest area for the aggregation of the soil. The microbial biomass was more responsive to variations in management and seasonality. The deployment of agroforestry systems contributes to the formation of a more diversified agricultural matrix, promoting improvements in the soil quality and connection with the remaining adjacent forest.

Abstract The stage of natural forest regeneration may influence soil fauna. This study aimed to test the hypothesis that there are differences in the structure and composition of the soil fauna communities between areas undergoing less advanced (LAS) and more advanced (MAS) stages of natural regeneration of Seasonal Semideciduous Forest at Pinheiral, RJ. Soil fauna was sampled using pitfall traps, during dry and rainy seasons. Total abundance, abundance of the saprophagous/predator group, mainly Formicidae, and the relative participation of Orthoptera were higher in MAS, while the relative participation of Acari, Araneae, Coleoptera, Diptera and the herbivorous group were higher in LAS, during both climatic seasons. Some taxonomic groups were restricted to one of the areas. Richness, evenness and diversity tended to present higher values in LAS (dry season). The higher complexity of the soil fauna community was correlated to the higher leaf litter standing stock in LAS.

ABSTRACT The objective of this study was to evaluate the influence of natural pasture and spontaneous regeneration on soil chemical properties and epigeal fauna community using a secondary Atlantic Forest as reference. The study areas were located in Passa Vinte, Minas Gerais, Brazil. In each study area, pitfall traps were used to sample epigeal fauna in the dry and rainy seasons. Earth samples were collected at a depth of 0-5 cm in the dry and rainy seasons for analysis of chemical attributes. The pasture and regeneration areas showed an overall activity of epigeal fauna and functional groups similar to the forest area. However, the diversity evaluated by the Shannon and Pielou evenness indices and the total richness were lower than the observed in the forest. The best fertility attributes were observed in the forest and pasture areas.