Kinetics and mineralization fraction of organic matter from sewage sludge mixed with soil under controlled laboratory conditions.

The objective of this work was to evaluate the kinetics and mineralization fraction of organic matter from sewage sludge mixed with the soil under controlled laboratory conditions. For this, organic material samples accumulated in layers 0-5 cm, 5-10 cm and 10-15 cm in relation to the surface of a vertical flow constructed wetland system (VF-CW) used for treatment of septic tank sludge, in addition to samples of dewatered sludge from a septic tank and a UASB reactor and non-dewatered sludge from an anaerobic digester were mixed with material collected from the surface layer of a Red Yellow Argisol at rates equivalent to the applications, via organic residues, of 300 and 600 kg ha-1 year-1 of total nitrogen. It was found that the two-phase kinetic equation fit better to the mineralization data of labile and recalcitrant organic carbon. For the lowest nitrogen application rate in the mixtures, the mineralization fractions of the total organic carbon were higher than 73%, while at the highest dose there was a reduction in the mineralization of organic matter by 17% and 63%, respectively in samples collected in layer 10-15 cm from the VF-CW and in the septic tank sludge dewatered in the drying bed.

Variabilidade espacial de atributos físicos de solos antropogênico e não antropogênico na região de Manicoré, AM / Spatial variability of soil physical anthropogenic and non anthropogenic in the region of Manicoré, AM

Melhores conhecimentos sobre os solos antropogênicos podem auxiliar na construção de cenários futuros para a região amazônica, por meio de informações que subsidiem o planejamento sustentável. O objetivo deste trabalho foi avaliar a variabilidade espacial de atributos físicos de solos antropogênicos e não antropogênico na região de Manicoré, AM. Na área do estudo foram selecionadas duas, uma com solos não antropogênicos (floresta nativa) e outra com solos antropogênicos (terra preta arqueológica). Em cada área, foi estabelecida uma malha medindo 70 x 70 m e os solos foram amostrados nos pontos de cruzamento da malha, com espaçamentos regulares de 10 em 10 metros, perfazendo um total de 64 pontos amostrais em cada paisagem. Foram coletadas amostras de solos na profundidade de 0,0 a 0,10 m e realizadas as análises físicas (textura, densidade do solo, macroporosidade, microporososidade, porosidade total e estabilidade dos agregados). Em seguida, os dados foram submetidos á estatística descritiva e geoestatística. Verificou-se que os solos antropogênicos e não antropogênicos apresentaram comportamentos diferenciados em relação ás suas estruturas espaciais. A variabilidade espacial que predominou no solo antropogênico e não antropogênico foi moderada e fraca indicando que estes solos estão fortemente ligados a alterações ocorridas por fatores extrinsecos no solo. No solo antropogênico foi observado melhores resultados para a porosidade total, microporosidade e densidade do solo, evidenciando características superiores para fins agronômicos quando comparado ao solo não antropogênico. E os valores de alcance encontrado nas duas áreas foram acima do utilizado na malha, evidenciando maior continuidade espacial nestes ambientes.

Better knowledge of the anthropogenic soils can help create future scenarios for the Amazon region through information that supports the sustainable planning. The aim of this study was to evaluate the spatial variability of soil physical anthropogenic and not anthropogenic in the region of Manipur, AM. In the study area we selected two, one with no anthropogenic soils (native forest) and another with anthropogenic soils (black earth archaeological). In each area, we established a grid measuring 70 x 70 m and the soils were sampled at the points of intersection of the grid with regular spacing of 10 by 10 feet, making a total of 64 sampling points in each landscape. Soil samples were collected at a depth from 0.0 to 0.10 I did the analyzes physical (texture, bulk density, macroporosity, microporososidade, porosity and aggregate stability). Then, the data were subjected to descriptive statistics and geostatistics. It was found that the anthropogenic and non-anthropogenic soils showed different behaviors in relation ace their spatial structures. The spatial variability that prevailed in anthropogenic and non-anthropogenic soil was moderate and weak indicating that these soils are strongly linked to changes in the soil by extrinsic factors. The soil was observed anthropogenic best results for total porosity, microporosity and bulk density, showing superior characteristics compared for agronomic soil not anthropogenic. And the range of values found in the above two areas were used in the mesh, showing greater spatial continuity in these environments.