Atributos químicos e físicos de um solo tratado com biossólido industrial e cultivado com milho

The effects of applying increasing doses of an industrial biosolid (0, 6, 12, 18 and 24 Mg ha -1 dry matter) and mineral fertilizer for two consecutive years in corn cultivation on the chemical and physical attributes of a distrophic Inceptisol under Brachiaria sp. have been evaluated in a field experiment. The chemical analysis showed that the biosolid application improved the soil fertility, especially in doses higher than 12 Mg ha -1, presenting higher organic carbon, nutrients and sodium contents, CEC, sum of bases and saturation percentage for bases and smaller pH than the control soil, with mineral fertilizer and of adjacent area, up to a depth of 0.6 m. The Cd and Pb contents were not altered significantly, while the nitrate and sodium contents increased with doses and depth, reaching 53 and 47 mg dm -3, respectively, in the 0.4-0.6 m depth layer with 24 Mg ha -1 of biosolid. The biosolid application enhanced soil aggregate stability, total porosity and microporosity and reduced soil density. The biosolid improved the fertility and the structure of soil, but its use as an agricultural input must be controlled, respecting criteria and standards so that the benefits of agricultural application overcome the risks of environmental pollution.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

The definition of potential infiltration areas in Guaratingueta watershed, Paraiba do Sul Basin, Southeastern Brazil: an integrated approach using physical and land-use elements

This work describes the methodological approach used for mapping the potential infiltration areas of the Guaratingueta watershed (160 km(2)), situated in Southeastern Brazil. The method is considered a qualitative approach, which takes into account thematic maps (geology, pedology, geomorphology, and land use/land cover) and the precipitation spatial distribution. A group of experts in Earth Sciences and Geotechnical Engineering has applied an infiltration potential scale factor that ranges from 5 (highest influence) to 1 (lowest influence). The final infiltration map was produced using several ArcGIS((R)) tools. The results showed that the most suitable (very high) infiltration areas represent only around 7% of the watershed area, which are associated with smooth and gentle hills, fluvial Tertiary sediments and yellow oxisols. However, growing impacts caused by land farming and urban developments require urgent planning for this region. Areas with high to moderate capacity of infiltration represent around 56% of the watershed and are found in the domain of igneous-metamorphic rocks associated with steep hill-slopes and relatively well-preserved forest fragments. This region requires a land-use strategy, such as reforestation programs, in order to increase the infiltration capacity of the watershed.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP