Quality of trace element contaminated soils amended with compost under fast growing tree Paulownia fortunei plantation

Abstract

The use of fast growing trees could be an alternative in trace element contaminated soils to stabilize these elements and improve soil quality. In this study we investigate the effect of Paulownia fortunei growth on trace element contaminated soils amended with two organic composts under semi-field conditions for a period of 18 months. The experiment was carried out in containers filled with tree different soils, two contaminated soils (neutral AZ and acid V) and a non contaminated soil, NC. Three treatments per soil were established: two organic amendments (alperujo compost, AC, and biosolid compost, BC) and a control without amendment addition. We study parameters related with fertility and contamination in soils and plants. Paulownia growth and amendments increased pH in acid soils whereas no effect of these factors was observed in neutral soils. The plant and the amendments also increased organic matter and consequently, soil fertility. Positive results were also found in soils that were only affected by plant growth (without amendment). A general improvement of "soil biochemical quality" was detected over time and treatments, confirming the positive effect of amendments plus paulownia. Even in contaminated soils, except for Cu and Zn, trace element concentrations in leaves were in the normal range for plants. Results of this mid-term study showed that Paulownia fortunei is a promising species for phytoremediation of trace element polluted soils.

Improving sustainability in the remediation of contaminated soils by the use of compost and energy valorization by Paulownia fortunei

“…2), illustrating the benefits of amendment application in this degraded soil by the enhancement of the processes of natural attenuation of metal toxicity. The amendment provoked a clear improvement in soil quality in the studied soils, as indicated by increases in available nutrients and in biochemical indexes of microbial activity (Madejón et al, 2014). Other authors have observed similar results in different experiments with amendment application (Park et al, 2011), pointing out the benefits of quality material addition for plant productivity.…”

“…Recent studies have shown that some Paulownia species show a relatively high tolerance to the presence of high concentrations of trace elements in the soil (Jiang et al, 2012;Madejón et al, 2014). Species in the Paulownia genus are highly adaptive to a wide range of climate and soil conditions (Yadav et al, 2013), and their use has been proposed for the afforestation of semi-arid areas, given their relatively good performance even under low water irrigation regimens (García-Morote et al, 2014).…”

The potential of native species as bioenergy crops on trace-element contaminated Mediterranean lands

“…7), which are the soils with the highest levels of organic matter content. This is in agreement with other works with remediated soils that showed that the activity of these two enzymes is mainly determined by the availability of organic C substrates (Caravaca et al, 2003;Madejón et al, 2014). In general, there was a trend for higher enzyme activities in the rhizosphere of S. marianum than in C. cardunculus or D. viscosa rhizospheres (Fig.…”

Biochar Amendment Associated to Compost and/or Iron in Order to Improve Lead and Arsenic Soil Stabilization and Salix Viminalis Growth

“…Among amendments, biochar, a carbonaceous product obtained from the pyrolysis of biomass under low oxygen conditions, was shown as a good soil conditioner to ameliorate soil fertility, thus to promote plant growth [4]. Additionally to biochar, compost also has been demonstrated to improve soil conditions; this product is formed through microbial degradation, it is rich in humic substances, microorganisms and inorganic components [5]. However, both biochar and compost showed efficient sorption capacities towards metal cations but not to metal anions [6].…”