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

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.