RESUMO

Soil Health refers to the ecological equilibrium and the functionality of a soil and its capacity to maintain a well balanced ecosystem with high biodiversity above and below surface, and productivity. To understand and use soil health as a tool for sustainability, physical, chemical, and biological properties must be employed to verify which respond to the soil use and management within a desired timescale. Attributes with a rapid response to natural or anthropogenic actions are considered good indicators of soil health. Among the physical indicators, soil texture, aggregation, moisture, porosity, and bulk density have been used, while among chemical indicators total C and N, mineral nutrients, organic matter, cation exchange capacity, among others are well established. However, most of them generally have a slow response, when compared to the biological ones, such as microbial biomass C and N, biodiversity, soil enzymes, soil respiration, etc., in addition to macro and mesofauna. Thus, a systemic approach based on different kinds of indicators (physical, chemical and biological) in assessing soil health would be safer than using only one kind of attribute. Many human activities have caused desertification, loss of biodiversity, disruption of aggregates, loss of organic matter and nutrients, among others. Today, it is imperious to maintain soil health and productivity with increasing emphasis on reforestation and recuperation of degraded areas through the use of organic amendments, reintroduction of plants, soil fauna and microorganisms. This review focused on an integrative view on indicators of soil health to be used as tools for prediction of sustainability in production systems.

RESUMO

Soil Health refers to the ecological equilibrium and the functionality of a soil and its capacity to maintain a well balanced ecosystem with high biodiversity above and below surface, and productivity. To understand and use soil health as a tool for sustainability, physical, chemical, and biological properties must be employed to verify which respond to the soil use and management within a desired timescale. Attributes with a rapid response to natural or anthropogenic actions are considered good indicators of soil health. Among the physical indicators, soil texture, aggregation, moisture, porosity, and bulk density have been used, while among chemical indicators total C and N, mineral nutrients, organic matter, cation exchange capacity, among others are well established. However, most of them generally have a slow response, when compared to the biological ones, such as microbial biomass C and N, biodiversity, soil enzymes, soil respiration, etc., in addition to macro and mesofauna. Thus, a systemic approach based on different kinds of indicators (physical, chemical and biological) in assessing soil health would be safer than using only one kind of attribute. Many human activities have caused desertification, loss of biodiversity, disruption of aggregates, loss of organic matter and nutrients, among others. Today, it is imperious to maintain soil health and productivity with increasing emphasis on reforestation and recuperation of degraded areas through the use of organic amendments, reintroduction of plants, soil fauna and microorganisms. This review focused on an integrative view on indicators of soil health to be used as tools for prediction of sustainability in production systems.

RESUMO

The use of sewage sludge is a highly promising practice for the development of sustainable agricultural systems. The objective of this study was to evaluate doses of sewage sludge composted with and without Rhizobium inoculation in leaf N content, nodule number, nodule dry weight and plant during flowering. The experiment was conducted in the greenhouse of the Department of Soil Science and Natural Resources College of Agricultural Sciences of Botucatu, using as substrate used in vessels of 30 liters a Red Yelow Latosol sandy texture with experimental design adopted was randomized blocks constituted for 10 treatments and five doses of composted sewage sludge (0, 10, 20, 30, 40 t ha-1) with or without inoculation Bradyrhizobium japonic with three replications. There was an increase in the number and dry weight of nodules and shoot dry mass of soybeans due to the increase of the dose of sludge up to a dose of 20 t ha-1 and after this dose there was a decrease of these parameters. At a dose of 10 t ha-1 sludge compost inoculated seeds showed higher for foliar concentrations of N and number of nodules compared with uninoculated seeds. At a dose of 30 t ha-1 inoculated seeds were higher compared to uninoculated in all parameters.

A utilização de lodo de esgoto é uma prática altamente promissora para o desenvolvimento de sistemas agrícolas sustentáveis. O objetivo deste trabalho foi avaliar doses de lodo de esgoto compostado, com e sem a inoculação do rizóbio, no teor de N foliar, número de nódulos, massa seca de nódulos e da planta no florescimento. O experimento foi conduzido em casa de vegetação do Departamento de Ciência do Solo e Recursos Naturais da Faculdade de Ciências Agronômicas de Botucatu, utilizando como substrato vasos de 30 litros de um Latossolo Vermelho Amarelo com textura arenosa Foi adotado o delineamento experimental em blocos casualizados constituído por 10 tratamentos, sendo cinco doses de lodo de esgoto compostado (0, 10, 20, 30, 40 t ha-1) com ou sem a inoculação do Bradyrizobium Japonic, com 3 repetições. Houve acréscimo no número e massa seca dos nódulos e na massa seca da parte aérea da soja com o aumento da dose de lodo até 20 t ha-1 e, posterior a esta dose ocorreram decréscimos destes parâmetros. Na dose de 10 t ha-1 de lodo compostado as sementes inoculadas apresentaram superior para os teores foliares de N e número de nódulos comparados com as sementes não inoculadas. Na dose de 30 t ha-1 as plantas provenientes de sementes inoculadas foram superiores em relação a não inoculadas em todos os parâmetros analisados.

RESUMO

The use of sewage sludge is a highly promising practice for the development of sustainable agricultural systems. The objective of this study was to evaluate doses of sewage sludge composted with and without Rhizobium inoculation in leaf N content, nodule number, nodule dry weight and plant during flowering. The experiment was conducted in the greenhouse of the Department of Soil Science and Natural Resources College of Agricultural Sciences of Botucatu, using as substrate used in vessels of 30 liters a Red Yelow Latosol sandy texture with experimental design adopted was randomized blocks constituted for 10 treatments and five doses of composted sewage sludge (0, 10, 20, 30, 40 t ha-1) with or without inoculation Bradyrhizobium japonic with three replications. There was an increase in the number and dry weight of nodules and shoot dry mass of soybeans due to the increase of the dose of sludge up to a dose of 20 t ha-1 and after this dose there was a decrease of these parameters. At a dose of 10 t ha-1 sludge compost inoculated seeds showed higher for foliar concentrations of N and number of nodules compared with uninoculated seeds. At a dose of 30 t ha-1 inoculated seeds were higher compared to uninoculated in all parameters.

A utilização de lodo de esgoto é uma prática altamente promissora para o desenvolvimento de sistemas agrícolas sustentáveis. O objetivo deste trabalho foi avaliar doses de lodo de esgoto compostado, com e sem a inoculação do rizóbio, no teor de N foliar, número de nódulos, massa seca de nódulos e da planta no florescimento. O experimento foi conduzido em casa de vegetação do Departamento de Ciência do Solo e Recursos Naturais da Faculdade de Ciências Agronômicas de Botucatu, utilizando como substrato vasos de 30 litros de um Latossolo Vermelho Amarelo com textura arenosa Foi adotado o delineamento experimental em blocos casualizados constituído por 10 tratamentos, sendo cinco doses de lodo de esgoto compostado (0, 10, 20, 30, 40 t ha-1) com ou sem a inoculação do Bradyrizobium Japonic, com 3 repetições. Houve acréscimo no número e massa seca dos nódulos e na massa seca da parte aérea da soja com o aumento da dose de lodo até 20 t ha-1 e, posterior a esta dose ocorreram decréscimos destes parâmetros. Na dose de 10 t ha-1 de lodo compostado as sementes inoculadas apresentaram superior para os teores foliares de N e número de nódulos comparados com as sementes não inoculadas. Na dose de 30 t ha-1 as plantas provenientes de sementes inoculadas foram superiores em relação a não inoculadas em todos os parâmetros analisados.

RESUMO

Actinobacteria are capable of playing several different roles in soil ecosystems. These microorganisms affect other organisms by producing secondary metabolites and are responsible for the degradation of different complex and relatively recalcitrant organic compounds. In our survey of actinobacteria isolated from the rhizosphere of Araucaria angustifolia, five culture media (AI, WYE, YCED, MSSC and LNMS) were compared for their effectiveness in isolating these microorganisms. When summing up all the isolates randomly obtained, we got 103 isolates. After isolation, the phosphate-solubilizing ability and the "in vitro" production of indole-acetic acid and chitinases were evaluated. The AI medium was ineffective for actinobacteria isolation, when it was compared with the other four culture media. Indole-acetic acid and chitinase were produced by respectively 36% and 24% of the strains tested. However, only 2% of the 103 strains presented some phosphate-solubilizing ability. These results demonstrate the biotechnological potential of these microorganisms.

Actinobactérias são capazes de desenvolver diferentes funções no ecossistema edáfico. Esses microrganismos, além de interagir com outros grupos de microrganismos e plantas, ao produzir metabólitos secundários, são responsáveis pela degradação de diferentes compostos orgânicos. Com intuito de facilitar os estudos envolvendo actinobactérias encontradas em sistemas florestais, cinco meios de cultura (AI, WYE, YCED, MSSC e LNMS) foram avaliados quanto à eficiência em isolar estes microrganismos. Além disso, foi analisada a capacidade dos diferentes isolados em solubilizar fosfato de cálcio, produzir ácido indol-acético e quitinases. Dos cinco meios de cultura testados, somente o AI foi ineficiente em isolar actinobactérias. A produção de ácido indol-acético e quitinases foi observada em 36% e 24% dos isolados analisados, respectivamente. Contudo, apenas 2% dos 103 isolados foram capazes de solubilizar fosfato de cálcio. Estes resultados comprovam o potencial biotecnológico desses microrganismos.

RESUMO

Actinobacteria are capable of playing several different roles in soil ecosystems. These microorganisms affect other organisms by producing secondary metabolites and are responsible for the degradation of different complex and relatively recalcitrant organic compounds. In our survey of actinobacteria isolated from the rhizosphere of Araucaria angustifolia, five culture media (AI, WYE, YCED, MSSC and LNMS) were compared for their effectiveness in isolating these microorganisms. When summing up all the isolates randomly obtained, we got 103 isolates. After isolation, the phosphate-solubilizing ability and the "in vitro" production of indole-acetic acid and chitinases were evaluated. The AI medium was ineffective for actinobacteria isolation, when it was compared with the other four culture media. Indole-acetic acid and chitinase were produced by respectively 36% and 24% of the strains tested. However, only 2% of the 103 strains presented some phosphate-solubilizing ability. These results demonstrate the biotechnological potential of these microorganisms.

Actinobactérias são capazes de desenvolver diferentes funções no ecossistema edáfico. Esses microrganismos, além de interagir com outros grupos de microrganismos e plantas, ao produzir metabólitos secundários, são responsáveis pela degradação de diferentes compostos orgânicos. Com intuito de facilitar os estudos envolvendo actinobactérias encontradas em sistemas florestais, cinco meios de cultura (AI, WYE, YCED, MSSC e LNMS) foram avaliados quanto à eficiência em isolar estes microrganismos. Além disso, foi analisada a capacidade dos diferentes isolados em solubilizar fosfato de cálcio, produzir ácido indol-acético e quitinases. Dos cinco meios de cultura testados, somente o AI foi ineficiente em isolar actinobactérias. A produção de ácido indol-acético e quitinases foi observada em 36% e 24% dos isolados analisados, respectivamente. Contudo, apenas 2% dos 103 isolados foram capazes de solubilizar fosfato de cálcio. Estes resultados comprovam o potencial biotecnológico desses microrganismos.

RESUMO

The occurrence of rhizobial communities at four sites under natural vegetation and one site under pasture were examined. Isolates of rhizobia originating from crotalaria (C. junceae), common bean (Phaseolus vulgaris) and pigeon pea (Cajanus cajan) were studied in relation to population density, host specificity and the interaction between rhizobial occurrence, climatic conditions and soil properties. pH values and potential acidity were the soil properties that most affected rhizobial occurrence. Rhizobia from crotalaria and common bean were evaluated at four sites, and from pigeon pea, at five sites. Common bean was the most specific legume, followed by peanuts, crotalaria and pigeon pea.

Foi examinada a ocorrência de comunidades de rizóbios em quatro locais de vegetação natural e um local de pastagem. Isolados de rizóbio originados de crotalária (C. junceae), feijão (Phaseolus vulgaris) e guandu (Cajanus cajan) foram estudados em relação à densidade populacional, planta hospedeira e interação entre ocorrência de rizóbio, condições climáticas e propriedades do solo. Os valores de pH e potencial de acidez foram as propriedades do solo que mais contribuíram para a ocorrência de rizóbio. A ocorrência de rizóbio em crotalária e feijão foi estudada em quatro locais, e em guandu em cinco locais. O feijão foi mais específico, seguido por crotalária e guandu.

RESUMO

Araucaria angustifolia is an important Brazilian conifer, but it is endangered of extinction due to excessive logging. The objective of the present case study was to survey data on the diversity of AMF in Araucaria angustifolia forests, and to learn whether it is possible to discriminate between the AMF communities associated with natural, introduced, and impacted-by-anthropogenic-action ecosystems. Three ecosystems representative of the Campos do Jordão (São Paulo State, Brazil) region were selected, as follows: (i) a native climax forest, with predominance of Araucaria trees, without anthropogenic interference (NF), (ii) Araucaria forest introduced in 1959 (RE), and (iii) Araucaria forest introduced in 1958, submitted to accidental fire in July 2001 (RF). Sampling of rhizosphere soil was performed at a 0-20 cm depth around each Araucaria tree, and 2 m from the trunk, in the months of May and October, 2002. AMF spores were separated from the soil, counted, and taxonomically identified, while the roots were evaluated for mycorrhizal colonization. The ecological indices R (Richness), Is (Simpson's dominance index) and H (Shannon's diversity index) were calculated. All the data were submitted to univariate (two-way ANOVA) and correspondence analysis (CA). Considering both samplings and the three areas, twenty-six AMF species were found, distributed among five genera, Acaulospora and Glomus being the most frequent ones. There were no differences among the three areas for R, Is, and H. CA demonstrated that there is a spatial separation among the three areas, and the AMF that preferentially associated with each area.

A Araucaria angustifolia é uma importante conífera brasileira, mas encontra-se ameaçada de extinção. Levantaram-se dados sobre a diversidade de fungos micorrízicos arbusculares (FMAs) em florestas de Araucaria angustifolia, visando a discriminar entre as comunidades de FMAs associadas com ecossistemas natural, implantado e impactado pela ação antrópica. Foram selecionados três ecossistemas representativos da região de Campos do Jordão (estado de São Paulo), sendo: (i) Floresta nativa com predominância de araucária, em clímax, sem interferência antrópica (FN); (ii) Floresta de araucária introduzida em 1959 (RE); e (iii) Floresta de araucária introduzida em 1958, submetida a uma queima acidental em julho de 2001 (RF). As coletas de solo rizosférico foram realizadas, na profundidade 0-20 cm, ao redor de cada árvore e a 2 m do tronco, nos meses de maio e outubro de 2002. Determinaram-se a densidade, diversidade, esporulação, colonização radicular e realizou-se a identificação morfológica dos FMAs. Os índices ecológicos R (Riqueza de espécies), Is (índice de dominância de Simpson) e H (índice de diversidade de Shannon) foram calculados. Os dados foram submetidos à análise univariada (two-way ANOVA) e análise de correspondência (AC). Considerando os dois períodos de amostragem e os três ecossistemas estudados, foram identificadas 26 espécies de FMAs, sendo os gêneros Acaulospora e Glomus os mais freqüentes. Não houve diferenças para R, Is e H entre as três áreas estudadas. A AC demonstrou que houve separação espacial entre as três áreas e quais foram às espécies de FMAs preferencialmente associadas em cada área.

RESUMO

Araucaria angustifolia is an important Brazilian conifer, but it is endangered of extinction due to excessive logging. The objective of the present case study was to survey data on the diversity of AMF in Araucaria angustifolia forests, and to learn whether it is possible to discriminate between the AMF communities associated with natural, introduced, and impacted-by-anthropogenic-action ecosystems. Three ecosystems representative of the Campos do Jordão (São Paulo State, Brazil) region were selected, as follows: (i) a native climax forest, with predominance of Araucaria trees, without anthropogenic interference (NF), (ii) Araucaria forest introduced in 1959 (RE), and (iii) Araucaria forest introduced in 1958, submitted to accidental fire in July 2001 (RF). Sampling of rhizosphere soil was performed at a 0-20 cm depth around each Araucaria tree, and 2 m from the trunk, in the months of May and October, 2002. AMF spores were separated from the soil, counted, and taxonomically identified, while the roots were evaluated for mycorrhizal colonization. The ecological indices R (Richness), Is (Simpson's dominance index) and H (Shannon's diversity index) were calculated. All the data were submitted to univariate (two-way ANOVA) and correspondence analysis (CA). Considering both samplings and the three areas, twenty-six AMF species were found, distributed among five genera, Acaulospora and Glomus being the most frequent ones. There were no differences among the three areas for R, Is, and H. CA demonstrated that there is a spatial separation among the three areas, and the AMF that preferentially associated with each area.

A Araucaria angustifolia é uma importante conífera brasileira, mas encontra-se ameaçada de extinção. Levantaram-se dados sobre a diversidade de fungos micorrízicos arbusculares (FMAs) em florestas de Araucaria angustifolia, visando a discriminar entre as comunidades de FMAs associadas com ecossistemas natural, implantado e impactado pela ação antrópica. Foram selecionados três ecossistemas representativos da região de Campos do Jordão (estado de São Paulo), sendo: (i) Floresta nativa com predominância de araucária, em clímax, sem interferência antrópica (FN); (ii) Floresta de araucária introduzida em 1959 (RE); e (iii) Floresta de araucária introduzida em 1958, submetida a uma queima acidental em julho de 2001 (RF). As coletas de solo rizosférico foram realizadas, na profundidade 0-20 cm, ao redor de cada árvore e a 2 m do tronco, nos meses de maio e outubro de 2002. Determinaram-se a densidade, diversidade, esporulação, colonização radicular e realizou-se a identificação morfológica dos FMAs. Os índices ecológicos R (Riqueza de espécies), Is (índice de dominância de Simpson) e H (índice de diversidade de Shannon) foram calculados. Os dados foram submetidos à análise univariada (two-way ANOVA) e análise de correspondência (AC). Considerando os dois períodos de amostragem e os três ecossistemas estudados, foram identificadas 26 espécies de FMAs, sendo os gêneros Acaulospora e Glomus os mais freqüentes. Não houve diferenças para R, Is e H entre as três áreas estudadas. A AC demonstrou que houve separação espacial entre as três áreas e quais foram às espécies de FMAs preferencialmente associadas em cada área.

RESUMO

The occurrence of rhizobial communities at four sites under natural vegetation and one site under pasture were examined. Isolates of rhizobia originating from crotalaria (C. junceae), common bean (Phaseolus vulgaris) and pigeon pea (Cajanus cajan) were studied in relation to population density, host specificity and the interaction between rhizobial occurrence, climatic conditions and soil properties. pH values and potential acidity were the soil properties that most affected rhizobial occurrence. Rhizobia from crotalaria and common bean were evaluated at four sites, and from pigeon pea, at five sites. Common bean was the most specific legume, followed by peanuts, crotalaria and pigeon pea.

Foi examinada a ocorrência de comunidades de rizóbios em quatro locais de vegetação natural e um local de pastagem. Isolados de rizóbio originados de crotalária (C. junceae), feijão (Phaseolus vulgaris) e guandu (Cajanus cajan) foram estudados em relação à densidade populacional, planta hospedeira e interação entre ocorrência de rizóbio, condições climáticas e propriedades do solo. Os valores de pH e potencial de acidez foram as propriedades do solo que mais contribuíram para a ocorrência de rizóbio. A ocorrência de rizóbio em crotalária e feijão foi estudada em quatro locais, e em guandu em cinco locais. O feijão foi mais específico, seguido por crotalária e guandu.