Revista Brasileira de Ciência do Solo
On-line version ISSN 1806-9657
ESCOSTEGUY, Pedro Alexandre Varella et al. Nutrient extraction by macrophytes cultivated in a solid waste landfill leachate. Rev. Bras. Ciênc. Solo [online]. 2008, vol.32, n.2, pp.853-860. ISSN 1806-9657. http://dx.doi.org/10.1590/S0100-06832008000200039.
Plant nutrient extraction has been used to remove inorganic ions from soil or other polluted media. In this study, the nutrient extraction capacity of the macrophytes Typha sp. and Eleocharis sp., cultivated as monoculture and as consortium, was evaluated in a growing medium containing rubble and leachate of an urban landfill. The plants were grown in wooden boxes containing rubble and leachate as substrate, in a plastic greenhouse, for five months. The total concentration and amount of macro (N, P, K, Ca, Mg, S) and micronutrients (Fe, Mn, Cu, and Zn), extracted per plant and per area, the dry matter production and the plant density were evaluated. These variables were analyzed in the plant shoots in five harvests (once a month). In general, the nutrient concentrations and amounts, extracted per plant and per area, did not differ between the monoculture and the consortium, except for the amounts of P, K, and Zn extracted per area, which were higher in the consortium. A higher quantity of macronutrients was extracted by Typha sp. than by Eleocharis sp. The macronutrients decreased in the following quantitative order: K > N > Ca > P ~ Mg > S (Typha sp.) and K > N > P ~ Ca ~ Mg ~ S (Eleocharis sp.), and the micronutrients as follow: Mn > Fe> Zn > Cu. The extracted amount of K was 648 (Typha sp.) and 159 kg ha-1 (Eleocharis sp.), and of Mn 6.6 (Typha sp.) and 1.4 kg ha-1 (Eleocharis sp.). The amount of extracted nutrients (per plant and per area) was related to the nutrient contents and dry matter production, but poorly related to plant density, both in monoculture and consortium. The nutrient quantity extracted from the leachate by Typha sp. was high, mainly for K, N, and Mn.
Keywords : soil pollution; plant nutrition; environmental decontamination.