Field plot experiments were conducted to study the intercropping systems of the hyperaccumulator Sedum plumbizincicola and passion fruit. Three planting densities of S. plumbizincicola were tested: low (D1: 30cm×30cm), medium (D2: 25cm×25cm), and high (D3: 15cm×15cm). Additionally, two microbial agents, Bacillus megaterium (Bm) and Bacillus mucilaginosus (Bmk), were applied at the medium density (D2). The effects of different treatments on the plant growth, heavy metal accumulation, and phytoextraction efficiency were investigated. The results showed that under the intercropping system, high density planting (D3) significantly increased the aboveground biomass of S. plumbizincicola and its phytoextraction efficiency for soil Cd and Zn, with annual extraction rates increased by 62.5% and 72.7%, respectively, compared with low density planting (D1) (P<0.05). The Cd content in passion fruit pulps decreased with increasing planting density of S. plumbizincicola and met the national food safety standards. Moreover, the application of Bmk in the intercropping system had a better effect on the growth of S. plumbizincicola and its ability to absorb Cd and Zn. Compared with CK, the aboveground biomass of S. plumbizincicola in Bmk treatment increased by 43.2%, and the uptake of Cd and Zn in the aboveground parts increased by 7.02% and 20.9%, respectively. The microbial application significantly reduced the pH value and significantly increased the available Cd and Zn content in both rhizosphere and non-rhizosphere soils, while Bmk had better effect than Bm. In all, this study provides a theoretical basis for improving soil heavy metal remediation under the intercropping system of hyperaccumulators and fruits.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |