SOIL CHEMICAL ATTRIBUTES RELATIONSHIPS AROUND THE Araucaria angustifolia TREES IN AGROFORESTRY SYSTEMS

This work aimed to understand the relationships between araucaria trees and some abiotic factors (soil type, soil organic C and soil nutrient supply) in agroforestry systems (AFS). Soils of two production areas in south-central region of the state of Parana (Bituruna - B and São Mateus do Sul - M) were characterized and soil chemical attributes were determined in microsites close to araucaria trees. B area presented only “juvenile” trees, while M area was formed by “juvenile” and “adult” trees. According to the multiple linear regression analyses, the soil chemical attributes showed an almost total dependence of the microsites depth. Soil chemical attributes dependence was much more diffuse in relation to the distances from the tree insertion in the soil. The non-metric multidimensional scaling ordination according to soil chemical attributes showed a great overlap of behavior of these tree groups. The chemical attributes comparison generated, to a certain extent, a soil fertility deficiency gradient between the microsites of the three groups of trees (MJ < MA < BJ). AFS with shaded Ilex paraguariensis must consider the replacement of nutrients exported by leaf harvest, which will help in the sustainability of the activity. This includes the environmental services that the AFS promotes by maintaining, or even renewing, of the native trees from the local forest, especially araucaria trees, in a productive system

Geoestadística en la producción integrada de frutas en el nordeste de Brasil

The objective of this work was initially to acess spatial variations of soils integrated production fruits in the northeast of Brazil in geoestatistics techniques. The study area owns 35.98 ha with coconut palm irrigated by micro-aspersion. The collection of data of physical and chemical attributes of the soil was realised (clay of soils, particlesize- distribution, organic C, pH water, P, Ca+Mg, K, Na, To, SB and CTC) in 93 points samples. The obtained datas were associated to the geographical coordinates by GPS. After the mathematical adjustment for the semi-variogram models in software Surfer 8.0, defining the parameters: effect nugget (C0); reach of the spatial dependence (A0); platform (C0+C1) and the spatial dependence degree (C0)/(C0+C1). Finally, the elaboration of contouring maps was performed by the kriging interpolator geoestatistc method. The results indicate the attributes with high degree of heterogeneity predominate. The ratio C0/(C0+C1) analysis revealed a moderate to strong degree of spatial dependency. Two management units were established for the study area, which require differentiated water and soil management practices.El objetivo de este estudio es mapear las variaciones espaciales del suelo de área con producción integrada de frutas en el nordeste de Brasil por medio de técnicas geoestadísticas. El área de estudio posee 35,98 ha con cocotero irrigado por microaspersión. Se realizó la recolección de datos por medio de atributos físicoquímicos del suelo (tenor de arcilla, granulometría, C orgánico, pH agua, P, Ca+Mg, K, Na, Al, SB y CTC) en 93 puntos muestrales. Los datos fueron asociados a las coordenadas geográficas locales por GPS. Después se efectuó el ajuste matemático por semivariogramas en el aplicativo Surfer 8.0, se definieron los parámetros: efecto pepita (C0); alcance de la dependencia espacial (A0); nivel (C0+C1) y el grado de dependencia espacial (C0)/(C0+C1). Del mismo modo, se elaboraron mapas de isolíneas de atributos a partir del interpolador geoestadístico de kriging. Los resultados obtenidos indican el predominio de atributos con elevado grado de heterogeneidad. El análisis de la relación C0/(C0 + C1) reveló grado de dependencia espacial de moderado a fuerte en los atributos analizados. De esa forma, se establecieron dos unidades de manejo para el área, las cuales exigen prácticas de irrigación y de abono diferenciadas

Carbon stocks and pools in relation to the texture of kaolinitic soils from the brazilian east coast

Extremely kaolinitic soils of Tertiary age elevations on the Brazilian east coast present a wide range of texture, which is recognized as one of the main factors controlling the soil organic matter contents. This study aimed to investigate the organic C storage of different compartments of kaolinitic soils. The studied soils had a wide particle size gradient, were under native forest vegetation, and located on Brazil’s eastern coast (Coruripe - CF, Umbaúba - UF, Nova Viçosa - VF, Sooretama - SF, and Itaboraí - IF). The forest cover of all sites allows to record soil properties reference values for a land use condition closer to that of the original sites. We determined soil organic C (SOC) content and SOC stock up to a depth of 1 m, C of topsoil (0.00-0.08 m), aggregate size classes, and dissolved organic carbon (DOC) of the soil surface horizon (A horizon). Soil C stocks at the 0.00-1.00 m depth ranged from 105 to 137 Mg ha-1 and were not regulated by soil texture. The SF soils stored more C up to a depth of 1 m, while lower mean C stocks were found for UF and CF soils. Soil texture was not a reliable index to predict the C contents of the aggregate size classes of the 0.00-0.08 m layer (within each class and in total, using equivalent soil mass of the classes). The most clayey soils had a high percentage of 2-4 mm aggregates and, as a consequence, high aggregate stability indices, which are positively correlated to silt plus clay contents of the soil surface horizon. The proportion of DOC in relation to the total organic C of the surface soil horizon was high for IF and UF areas, which are the less preserved forest fragments among all studied fragments

Soil profiles from three coastal plain regions. I. Morphology, characterization and classification

O objetivo deste trabalho foi caracterizar morfológica, física e quimicamente e classificar os solos de três áreas de restinga do litoral norte fluminense sob diferentes coberturas vegetais. O local Lagoa do Robalo (LGR) possui perfis de Podzol Hidromórfico com um horizonte espódico de acumulação de material húmico. No Canto do Santo Antônio (CSA) estão compreendidas areias pouco diferenciadas, classificadas como Areias Quartzosas Marinhas intermediárias para Podzol, assim adjetivadas para realçar o débil processo de acúmulo subsuperficial de material fino e de matéria orgânica. Em Campos Novos (CNO), os perfis de Podzóis com horizonte subsuperficial espódico de acumulação de material oxídico associado à matéria orgânica são bem diferenciados. Na LGR, os perfis de Podzóis Hidromórficos ocorrem como função da conjunção do material de origem inerte e poroso; da presença permanente de um lençol freático flutuante próximo à superfície; e da vegetação nativa arbustiva. No CSA, os perfis de Areias Quartzosas Marinhas intermediárias para Podzol, com exceção do horizonte superficial, poucas e tênues diferenças foram impostas pela troca da cobertura vegetal nativa pelo uso agrícola. Em CNO o perfil sob pasto está drasticamente despodzolizado. A exuberância do horizonte Bshx do perfil sob cobertura vegetal nativa é extremamente influenciada pelo eficiente dessecamento imposto pelo consumo de água da floresta local.The objective of this work was to characterize morphologically, physically and chemically soils of three regions of the coastal plain in northern part of the Rio de Janeiro state with different vegetation cover, in order to classify them. Lagoa do Robalo (LGR) region showed a profile of Gleyic Podzol with a spodic horizon of humus accumulation. Low differentiated sandy soils were observed at the Canto do Santo Antônio (CSA) region, which was classified as intermediary Luvic Arenosols to Podzol. Such a denomination was proposed in order to emphasize the feeble subsurface accumulation process of fine fractions and organic matter. Campos Novos (CNO) region, with soil profiles classified as well differentiated Podzols, showed subsurface spodic horizon of oxidic material accumulation associated to organic matter. The Gleyic Podzol with Bh horizon found at the LGR region was developed due to the conduction of the inert and porous parent material, high level of groundwater near the soil surface, and native shrubby cover. Except for the superficial horizons, low and subtle differences were imposed by soil cultivation after deforestation of native cover at the CSA region. The soil profile at the CNO region under pasture grass, showed strong depodzolization. The magnitude of the Bshx horizon from the soil profile under native cover is highly affected by an efficient drying process imposed by water absorption of the local forest

Morfologia, mineralogia e micromorfologia de solos de depressões de topo de Tabuleiros Costeiros do Nordeste Brasileiro

The scarcity of comprehensive characterizations of soils associated to gentle summit depressions of the Northeastern Brazilian Coastal Plains justifies this work, which had as objective to provide basic information for the more diverse agricultural and non-agricultural uses. For that, representative soils (Spodosols or similar soils) from these environments were selected in Alagoas, Sergipe and Bahia states. This approach included characterization of morphological, mineralogical and micromorphological properties of the soil profiles, employing standard procedures. The morphological characterization corroborated the effect of the podzolization process during the formation of these soils. The mineralogy of the clay fraction of these soils was basically composed of kaolinite and quartz, which, associated to the very sandy texture, helped in the understanding of the obtained data. The soil micromorphological study, besides confirming the field morphology, mainly in regard to the strong cementation, aggregated value to the work in terms of the secure identification of the clay illuviation process (non-identified in the field), in association with the dominant podzolization process

Geoestadística en la producción integrada de frutas en el nordeste de Brasil

The objective of this work was initially to acess spatial variations of soils integrated production fruits in the northeast of Brazil in geoestatistics techniques. The study area owns 35.98 ha with coconut palm irrigated by micro-aspersion. The collection of data of physical and chemical attributes of the soil was realised (clay of soils, particlesize- distribution, organic C, pH water, P, Ca+Mg, K, Na, To, SB and CTC) in 93 points samples. The obtained datas were associated to the geographical coordinates by GPS. After the mathematical adjustment for the semi-variogram models in software Surfer 8.0, defining the parameters: effect nugget (C0); reach of the spatial dependence (A0); platform (C0+C1) and the spatial dependence degree (C0)/(C0+C1). Finally, the elaboration of contouring maps was performed by the kriging interpolator geoestatistc method. The results indicate the attributes with high degree of heterogeneity predominate. The ratio C0/(C0+C1) analysis revealed a moderate to strong degree of spatial dependency. Two management units were established for the study area, which require differentiated water and soil management practices.El objetivo de este estudio es mapear las variaciones espaciales del suelo de área con producción integrada de frutas en el nordeste de Brasil por medio de técnicas geoestadísticas. El área de estudio posee 35,98 ha con cocotero irrigado por microaspersión. Se realizó la recolección de datos por medio de atributos físicoquímicos del suelo (tenor de arcilla, granulometría, C orgánico, pH agua, P, Ca+Mg, K, Na, Al, SB y CTC) en 93 puntos muestrales. Los datos fueron asociados a las coordenadas geográficas locales por GPS. Después se efectuó el ajuste matemático por semivariogramas en el aplicativo Surfer 8.0, se definieron los parámetros: efecto pepita (C0); alcance de la dependencia espacial (A0); nivel (C0+C1) y el grado de dependencia espacial (C0)/(C0+C1). Del mismo modo, se elaboraron mapas de isolíneas de atributos a partir del interpolador geoestadístico de kriging. Los resultados obtenidos indican el predominio de atributos con elevado grado de heterogeneidad. El análisis de la relación C0/(C0 + C1) reveló grado de dependencia espacial de moderado a fuerte en los atributos analizados. De esa forma, se establecieron dos unidades de manejo para el área, las cuales exigen prácticas de irrigación y de abono diferenciadas

Solos de tabuleiros costeiros sob florestas naturais e sob cultivo

Landscapes formed on Barreiras Formation sediments occupy significant area on Brazilian territory. Many of these landscapes have highly intensive agricultural use, due to favorable climate and topography. The objective of this study was to characterize and to compare soil profiles situated on non-dissected coastal plains from southern Bahia to Alagoas, occurring under natural vegetation (forest) and agricultural use. Seven soil profiles were analyzed and data from six soil profiles obtained in other works were incorporated. Particle size distribution, organic C (OC), Al, Ca, Mg, Al+H, K, Na, P, Fe, Ti and Si were determined. Clay mineralogy was analyzed by X-ray diffraction. Soil profiles occur on flat relief, have yellow color, weak small to medium subangular blocky structure on B horizon and sub-superficial cohesive character. Texture was the most significant attribute that differentiated soil profiles from each other. All soils have low Fe content. X-ray diffraction results showed kaolinite dominance in the clay fraction. The soil OC was the only attribute tested that significantly varied between the surface materials of forest soils and the cultivated systems (sugarcane, orange, coconut and eucalyptus)

Chemical and mineralogical soil atributes from Comperj area due to variations in lithotype, landscape position and vegetation cover

<p>Establishing Comperj (petrochemical complex Petrobras and partner companies at Itaboraí city, Rio de Janeiro State, Brazil) involves a great impact on natural environment, while it is an opportunity for actions of environmental compensation. The objectives of this study were to characterize soil chemistry and mineralogy of Comperj<br />area, based on landscape, particle size distribution and soil morphology, also considering different parent materials, landscape positions (shoulder, backslope and footslope at the hillslope and toeslope at floodplain) and vegetation cover groups. Different landscape positions, comparing toeslope and average hillslope, have differential behavior on several chemical attributes, besides those associated with landscape position itself (topography and water regime). Along the hillslope, differences on surface soil samples also occurred, considering studied attributes, among different parent materials and vegetation cover<br />groups. Sites of both vegetation cover groups (forest and pasture) along the hillslope showed differences on many chemical attributes, except for organic C average values<br />that were not differentiated among them. Soil mineralogy on all samples was extremely kaolinitic and there were small differences among parent material groups. Soil<br />consistencies observed were very to extremely hard on both soil parent material groups, Proterozoic and Tertiary.</p

Soil profiles from three coastal plain regions. II. Dynamics of humic substances, iron and aluminum

Substâncias húmicas foram fracionadas e feitas extrações de Fe e Al com ditionito (Fed e Ald), oxalato (Feo e Alo) e pirofosfato de sódio (Fep e Alp) com o intuito de estudar os aspectos de formação de solos de três áreas de restinga no litoral norte fluminense sob diferentes coberturas vegetais. No ambiente de forte hidromorfismo da Lagoa do Robalo, ácidos húmicos (AH) preponderaram sobre a fração ácidos fúlvicos (AF). Nas áreas do Canto de Santo Antônio e de Campos Novos, a relação AH/AF decresceu em profundidade. Os valores de Fe foram extremamente baixos nas amostras dos perfis da Lagoa do Robalo. Nos horizontes B dos perfis de Campos Novos, os valores de Fe extraído variaram entre 0,74 e 1,13 g/kg e confirmam a morfologia desses perfis, com horizontes iluviais avermelhados. A podzolização dos perfis pode ser observada de forma mais clara pela tendência de os horizontes iluviais de cada perfil acumularem mais Al extraível pelo pirofosfato do que os demais horizontes de cada perfil. Na Lagoa do Robalo o processo de podzolização foi atribuído a compostos orgânicos migrantes. As baixas relações carbono orgânico/(Fep + Alp) denotam uma sobra de íons metálicos nos horizontes iluviais dos perfis do Canto de Santo Antônio. Em Campos Novos o perfil de Podzol com horizonte Bsh sob pasto está drasticamente despodzolizado, mas ainda mantém seu caráter iluvial para complexos organometálicos.Humic substances were characterised and Fe and Al were determined after extraction with dithionite (Fed e Ald), oxalate (Feo e Alo) e sodium pyrophosphate (Fep e Alp) for soil genesis studies from three Coastal Plain regions with different vegetation cover, in the northern Rio de Janeiro State. Lagoa do Robalo region with strong hydromorphism showed higher amounts of humic acid (HA) than fulvic acid (FA). Canto do Santo Antônio and Campos Novos regions showed decreasing HA/FA ratio with increasing soil depth. Iron concentration was very low in soil samples of the Lagoa do Robalo profile. B horizons from profiles of the Campos Novos region showed the highest levels of Fep (0.74 to 1.13 g/kg) thus confirming their morphology with red illuvial horizon. Podzolization of the profiles was more clearly observed through the trend of illuvial horizons in accumulating more pyrophosphate extractable Al than the others horizons in the same profile. Probably, the podzolization process at Lagoa do Robalo was due to migrating organic compounds. Low organic carbon/(Fep + Alp) ratio denotes a surplus of metal ions in illuvial horizons of the profiles of Canto de Santo Antônio region. At Campos Novos, Podzol profile with Bsh horizon under grassland pasture was drastically depodzolized, but it still keeps its illuvial character for organic metallic complexes