Intercropping of Pennisetum sinese with Lolium perenne improved phytoextraction of heavy metal from soil

Abstract

In order to find the optimum planting pattern for phytoremediation of metal‐accumulating plants in heavy metal‐contaminated soils, Pennisetum sinese and Lolium perenne were intercropped or monocultured, and the plant leaf physiological indexes as well as the heavy metal contents and accumulation of the two plants were determined. The contents, accumulation, and bioconcentration of Pb, Cd, Cu, and Zn in different parts of the two plants under the intercropping method were significantly (p < 0.05) higher than those under the monoculture method. The average accumulation amounts of Pb, Cd, Cu, and Zn in P. sinese under the intercropping method are 29.51, 19.60, 182.8, and 178.2 μg/plant in leaves; 8.89, 17.99, 61.68, and 205.4 μg/plant in stems; and 8.45, 2.18, 36.35, and 47.94 μg/plant in roots, respectively. The average accumulation amounts of Pb, Cd, Cu, and Zn in L. perenne under the intercropping method are 2.30, 1.40, 23.29, and 33.34 μg/plant in shoots and 1.43, 0.42, 3.21, and 6.98 μg/plant in roots, respectively. Thus, P. sinese has higher heavy metal accumulation. Compared with the monocultured plants, the average accumulation amounts of Pb, Cd, Cu, and Zn increased in both two plants. Therefore, intercropping P. sinese and L. perenne was the optimum planting pattern for heavy metal‐contaminated soil phytoremediation, and P. sinese was more suitable for heavy metal phytoextraction from soil.

Synergistic Phytoremediation of Cadmium-Contaminated Soil: Intercropping Rapeseed and Kenaf for Enhanced Biomass, Metal Uptake, and Soil Health

“…The decrease in soil pH was observed in all soil Cd treatments in intercropping. The ndings of our study align with previous research, which demonstrated that a decrease in soil pH leads to an increase in the bioavailability of Cd (Lian et al, 2022) and is the key reason for the greater root Cd uptake and higher Cd concentration in aboveground plant parts (Tsadilas et al, 2005;Zou et al, 2023). Bian et al (2021) found that intercropping bamboo and Sedum plumbizincicola led to an increase in biomass and a decrease in soil pH, which facilitated the removal of heavy metals from the soil.…”

Wide Riparian Zones Inhibited Trace Element Loss in Mining Wastelands by Reducing Surface Runoff and Trace Elements in Sediment

“…R. simsii and L. perenne showed potential in phytoextraction for soils contaminated with trace elements [ 52 , 53 ]. In the intercropping mode, the organic acids secreted by R. simsii roots may increase the bioavailability of trace elements in the soil, enhance the ability of R. simsii and L. perenne to accumulate trace elements, and promote the accumulation of L. perenne biomass [ 54 , 55 ]. This intercropping mode facilitated the transfer of trace elements in the soil to the vegetation, which, in turn, reduced the loss of trace elements from the riparian zone [ 9 ].…”