Effect of tree harvest intervals on the removal of heavy metals from a contaminated soil in a field experiment

Abstract

Four clones of short rotation coppice (SRCs) were investigated for phytoextraction of soil contaminated by risk elements (REs), especially Cd, Pb and Zn. As a main experimental factor, the influence of rotation length on the removal of REs was assessed. The field experiment with two Salix clones (S1 – (Salix schwerinii × Salix viminalis) ×S. viminalis; S2 – S. × smithiana) and two Populus clones (P1 – Populus maximowiczii × Populus nigra; P2 – P. nigra) was established in April 2008 on moderately contaminated soil. For the first time, all clones were harvested in February 2012 (2012<sub>4y</sub>) after 4 years. Subsequently each plot was equally split into halves. The first half of the SRC clones was harvested in February 2014 after 2 years (2014<sub>2y</sub>) and again it was harvested in February 2016 after further 2 years (2016<sub>2y</sub>). The second half was harvested in February 2016 after 4 years (2016<sub>4y</sub>). The results showed that the biomass production for the second 4-year harvest period was significantly higher for all clones but the metal concentration was lower in the mentioned period. 4-year rotation seems to be more advantageous for the phytoextraction than two 2-year rotations. The highest metal removal presented by remediation factors (RFs) per 4 years for Cd (6.39%) and for Zn (2.55%) were found for S2 in the harvest 2016<sub>4y</sub> treatment. Removal of Pb was the highest by P1 clone with very low RF per 4 years (0.04%). Longer rotation is also economically superior.

Effect of controlled soil drying on the grain yield and nutritional quality of rice

“…However, little is known about changes of them in grains under different irrigation regimes. With the rapid development of industry and agriculture, the content of heavy metals in farmland rises sharply (Kubátová et al, 2018). Heavy metals are easily absorbed by crops and can get into the human body through the food chain, which seriously endangers human health (Puschenreiter, Horak, Friesl, & Hartl, 2005).…”