Soil quality assessment of coal gangue piles under different ecological restoration pattern in Yunnan-Guizhou Mountainous area

Abstract

The paper aimed at the problem of soil quality and heavy metal pollution of coal gangue piles in Yunnan-Guizhou mountainous area, the soil quality and heavy metal pollution of copper, zinc, iron, manganese and other heavy metals in coal gangue piles at different ecological restoration pattern were determined, and the soil quality and pollution risk degree were evaluated. Results showed that soil pH value of the survey sites ranged from 3.04 to 8.11, soil organic matter content ranged from 48.58 g·kg−1 to 202.29 g·kg−1, soil total nitrogen content ranged from 0.66 g·kg−1 to 2.04 g·kg−1, soil available nitrogen content ranged from 5.25 mg·kg−1 to 33.25 mg·kg−1, soil total phosphorus content ranged from 0.61 g·kg−1 to 2.56 g·kg−1, soil available phosphorus content ranged from 0.46 mg·kg−1 to 102.41 mg·kg−1, soil total potassium content ranged from 9.44 g·kg−1 to 33.25 g·kg−1, and soil available potassium content ranged from 3.25 mg·kg−1 to 149.63 mg·kg−1; soil total copper content of the survey sites ranged from 66.76 mg·kg−1 to 225.83 mg·kg−1, soil total zinc content of the survey sites ranged from 115.15 mg·kg−1 to 368.48 mg·kg−1, Soil total iron content of the survey sites ranged from 22.57 g·kg−1 to 64.17 g·kg−1, and soil total manganese content of the survey sites ranged from 223.79 mg·kg−1 to 1898.57 mg·kg−1. These Results implied that the coal gangue piles were barren, nutrition and water retention need to be improved in the process of restoration, and the risk of soil copper and zinc pollution in these coal gangue piles were low.