The study analyzed the effects of different mulching durations(4 to 19 years)on the characteristics of microplastics in the soil of peanut fields. The results showed that as the mulching duration increased, the abundance of microplastics in the soil tended to rise. Compared with a mulching duration of 4 years, the abundance of microplastics in the soil with a mulching duration of 19 years varied between 660 and 3150 pieces/kg. The abundance of microplastics with a small particle size(<2mm)increased with both the mulching duration and soil depth. Long-term continuous mulching promoted the penetration of microplastics into deeper soil layers, which was specifically reflected in the fact that microplastics with a small particle size accounted for 49.9% in the 20~30cm soil layer. In sampling points with different mulching durations and soil depths, the color of microplastics was predominantly transparent, followed by black, green, and purple, while other colors such as red had relatively lower proportions. The shapes of microplastics included fibrous, foamy, film-like, fragmental, and granular, with fibrous shapes being the most dominant. Moreover, the polymer types of microplastics were diverse, mainly consisting of PE(polyethylene, 34.2%), PP(polypropylene, 17%), and PS(polystyrene, 16.3%). In summary, the increase in mulching duration significantly affected the proportion of transparent microplastics in the soil, but had no significant impact on the types of microplastics and polymers.
| 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 |