Soil amendments reduce trace element solubility in a contaminated soil and allow regrowth of natural vegetation.

We tested the effects of three amendments (a biosolid compost, a sugar beet lime, and a combination of leonardite plus sugar beet lime) on trace element stabilisation and spontaneous revegetation of a trace element contaminated soil. Soil properties were analysed before and after amendment application. Spontaneous vegetation growing on the experimental plot was studied by three surveys in terms of number of taxa colonising, percentage vegetation cover and plant biomass. Macronutrients and trace element concentrations of the five most frequent species were analysed. The results showed a positive effect of the amendments both on soil chemical properties and vegetation. All amendments increased soil pH and TOC content and reduced CaCl(2)-soluble-trace element concentrations. Colonisation by wild plants was enhanced in all amended treatments. The nutritional status of the five species studied was improved in some cases, while a general reduction in trace element concentrations of the aboveground parts was observed in all treated plots. The results obtained show that natural assisted remediation has potential for success on a field scale reducing trace element entry in the food chain.

ferias campesinas. Una estrategia socioeconomica

La investigacion se detiene en las ferias campesinas mas importantes de departamento de Oruro. Sus resultados permiten enfocar el tema de la economia, las estrategias campesinas y las ferias-fiestas no como un producto estructural de la historia economica regional, sino como dinamicas sociales en las que participan diferentes grupos en permanente proceso de recreacion