Abstract:In order to explore the pollution status and main sources of heavy metals in farmland soils around the Rongxi manganese mining area in Xiushan county, Chongqing. The contents of Cd, As, Pb, Cr, Ni, Cu, Zn and Mn in soils were determined, and the single factor pollution index, Nemerow pollution index and Muller index were used to evaluate the pollution level and distribution characteristics of heavy metals. Meanwhile, correlation analysis, PCA and APCS-MLR were employed to investigate the sources and contribution rate of heavy metals in soils. The results show that Mn average concentration in paddy soil is significantly lower than that in other farmland soils (p<0.05), and the average concentrations of other 7 heavy metals have no significant difference among different farmland soils (p>0.05). The comprehensive Nemerow pollution index is sweet potato field (13.34) > soybean field (2.73) > corn field (2.19) > paddy field (1.80), the sequence of heavy metal pollution is Mn > Cd > As > Ni, Zn > Pb, Cr and Cu. The accumulation degree of heavy metals in soil is Mn > As > Pb > Zn > Ni > Cd > Cu > Cr. The analysis of pollution sources shows that there is a significant positive correlation between Cd, Pb, Ni, Cu, Zn and Mn (r =0.5~0.8, p<0.01), which are mainly affected by mining activities, with contribution rates of 80.0%, 55.3%, 57.9%, 61.4%, 73.3% and 98.4%, respectively. Meanwhile, there is a significant positive correlation between As and Cr (r=0.548, p<0.01), which is mainly affected by natural factors such as soil parent material, with contribution rates of 88.5% and 76.3%, respectively. Therefore, it is necessary to strengthen the source control and pollution prevention of Mn and Cd. In addition, the accumulation degree of eight heavy metals pollution in sweet potato land is higher than that in other crop land, thus corresponding remediation should be carried out to prevent continuous pollution of sweet potato soil.