Abstract:

This study aims to explore the cadmium enrichment characteristics of rice varieties planted in Changtai District of Zhangzhou and the rice quality safety. 15 local main rice varieties were used as the experimental materials, and pot experiments and field experiments of adding cadmium were adopted. The cadmium enrichment coefficient of rice was investigated, and the risk of rice quality safety was evaluated. The results showed that the cadmium content of the 15 rice varieties was in the range of 0.026-0.10 mg/kg, 0.16-0.67 mg/kg and 0.32-1.18 mg/kg, respectively, when the total cadmium content of pot experiment was 0.060 mg/kg, 0.39 mg/kg and 0.65 mg/kg in light acidic paddy soil (5.5 < pH≤6.5). When the total cadmium content of the field experiment was 0.15 mg/kg, 0.21 mg/kg and 0.11 mg/kg in light acidic paddy soil (5.5 < pH≤6.5), the variation scope of cadmium content of the 15 rice varieties was 0.048-0.25 mg/kg, 0.083-0.36 mg/kg and 0.043-0.22 mg/kg, respectively. The cadmium content of the same rice variety was positively and linearly correlated with the total cadmium content in soil (P<0.01). There were significant differences in the enrichment ability of cadmium among different rice varieties (P < 0.05), and the enrichment coefficient of pot experiment and field experiment was 46.6%-179.3% and 38.3%-179.4%, respectively. Cluster analysis indicated that there were 2 rice varieties with high enrichment ability, 7 varieties with medium enrichment ability and 6 varieties with low enrichment ability. According to the limit standard of cadmium in rice in GB2762-2017 (0.2 mg/kg), for rice varieties with low, medium and high enrichment ability, the critical risk value of total cadmium was 0.31-0.41 mg/kg, 0.16-0.25 mg/kg and 0.11-0.12 mg/kg, respectively, in light acidic paddy soil (5.5<pH≤6.5). Overall, the cadmium enrichment characteristics of the 15 main rice varieties in Changtai District of Zhangzhou are significantly different. For rice variety planted in paddy fields where the total cadmium content is above the critical risk value, its cadmium content will have a quality safety risk of being higher than 0.2 mg/kg.

Key words: rice variety, rice, cadmium, enrichment characteristics, quality safety, risk assessment