Autor(es):
Varennes, Amarilis de 
; Queda, Cristina Cunha ; Guiwei, Qu
Data: 2009
Identificador Persistente: http://hdl.handle.net/10400.5/1585
Origem: Repositório da UTL
Assunto(s): mine soil; enzymatic activities; compost; polyacrylate polymers
Descrição
Many soils derived from pyrite mines spoils are acidic, poor in organic matter and plant
nutrients, contaminated with trace elements, and support only sparse vegetation. The establishment of a plant cover is essential to decrease erosion and the contamination of water bodies with acid drainage containing large concentrations of trace elements. We
tested the application of compost and polyacrylate polymers to promote the growth of indigenous plant species present in the mine area. Soil treatments consisted of unamended soil (control), soil with mineral fertilizers only, soil with fertilizer plus
compost, soil with fertilizer plus polyacrylate polymers, and soil with fertilizer plus both amendments. Half of the soil was grown with Briza maxima L.(greater quaking grass), Chaetopogon fasciculatus
(Link) Hayek (chaetopogon), and Spergularia purpurea(Persoon) G. Don fil. (purple sandspurry),while the remainder was left bare. In the absence of plants, the greatest improvements in soil conditions were obtained by the application of both amendments,which was associated with the greatest values of protease, acid phosphatase, and β-glucosidase, whereas
the activity of cellulase and microbial respiration were similar in soil amended with compost or polymer. Dehydrogenase activity was greatest in soil
with compost (with or without polymer), whereas urease activity was impaired by both amendments. In the presence of plants, the application of both amendments led to the greatest activities of protease,urease, β-glucosidase, cellulase, and microbial respiration, but acid phosphatase was mainly enhanced by polymer and dehydrogenase was increased by compost.
Plant growth was stimulated in all treatments
compared with unamended soil, but the greatest value for total accumulated biomass was obtained in fertilized soil receiving both amendments. However, species responded differently to treatment: while the
growth of B. maxima was greatest in soil with
compost and polymer, the growth of C. fasciculatus responded better to soil with compost, and S. purpurea grew better in polymer-amended soil. The amendments tested improved the quality of a mine
soil and stimulated plant growth. However, botanical composition likely changes over time with amendments,
and this needs to be considered when a large
scale application of amendments is projected.
