Comprehensive evaluation on safe utilization potential of ten oilseed rape cultivars in a cadmium contaminated soil

Abstract

Oilseed rape (Brassica napus L.) planting could be a promising approach for the safe utilization of cadmium (Cd) contaminated soil. However, comprehensive evaluation on safe utilization potential of oilseed rape was lacked, including phytoextraction efficiency, health risk, and economic benefits. In this study, ten oilseed rape cultivars were planted in Cd-contaminated soils immobilized with limestone and a comprehensive evaluation was performed on the safe utilization potential. Results showed that the highest biomass of rapeseed (1363-1569 kg ha⁻¹) was found in Zhongshuang 11, Xiangzayou 787, and Luoyouza 101. Zhongyouza 19, Zhongshuang 11 and Dadi 199 had the highest Cd phytoextraction efficiency (3.31-3.76 g ha⁻¹). The Cd concentrations in all the rapeseeds ranged from 0.18–0.45 mg kg⁻¹ and were lower than the limit of food security standards, but oil Cd concentrations of three cultivars (Fengyou 730, Dadi 199, and Yangguang 50) were 0.90-1.56 times higher than those in the reference oils (0.04-0.05 mg kg⁻¹). Target hazard quotient (THQ) suggested that the Cd in all the oils were under the acceptable level for adults and children, whereas only of three cultivars (Huihaoyou 26, Luoyouza 101, and Zhongshuang 11) were at acceptable level at incremental lifetime cancer risk (ILCR) value. Based on the yields and market price of rapeseed, Luoyouza 101, Xiangzayou 787, and Zhongshuang 11 had the highest economic benefits (9812-11300 CNY ha⁻¹). Overall, the comprehensive evaluation indicates that Zhongshuang 11 is the most suitable for the safe utilization of Cd contaminated soil.