Luo Wei, Wang Dongjie, Xu Zhou, Liao Guoping, Chen Defang, Huang Xiaoli, Wang Yan, Yang Song, Zhao Liulan, Huang Huagang, Li Yuliang, Wei Wenyan, Long Yuejin, Du Zongjun
College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
Environ Int. 2020 Oct;143:105898. doi: 10.1016/j.envint.2020.105898. Epub 2020 Jul 2.
The rice-fish coculture system (RFS) is one of the most important and environmentally friendly agricultural systems in the world. With the increasing amounts of heavy metal contamination in the soil and water, the safe production of RFS has been greatly threatened. However, there are no reports on heavy metal uptake by rice and fish in a RFS. In this study, a model of cadmium (Cd)-contaminated RFS with the addition of 0-40.00 mg kgCd was simulated in the field. The accumulation of Cd in the rice and fish increased as the level of Cd contamination increased. Regardless of the level of contamination, the order of Cd accumulation in the rice was root > stem ≈ leaf > rice grain > brown grain and in the fish was liver ≈ gut > kidney > gill > muscle. The dissolved oxygen (DO) and the transparency of water were significantly reduced after the fish were added. The tendency of the Cd to accumulate in the fish correlated with the change of the concentration of Cd in the water (P < 0.05). According to the maximum level of Cd in the brown grains (0.40 mg kg) and in the fish muscle (0.10 mg kg) of Codex Alimentarius Commission (CAC), the safety threshold of soil Cd for the rice and the fish was calculated to be 5.86 mg kg and 31.47 mg kg, respectively, indicating that the safety risk to the rice was much greater in a Cd-contaminated RFS.
稻鱼共生系统（RFS）是世界上最重要且环境友好的农业系统之一。随着土壤和水体中重金属污染量的增加，稻鱼共生系统的安全生产受到了极大威胁。然而，尚无关于稻鱼共生系统中水稻和鱼类对重金属吸收情况的报道。在本研究中，在田间模拟了添加0至40.00毫克/千克镉（Cd）的镉污染稻鱼共生系统模型。随着镉污染水平的增加，水稻和鱼类中镉的积累量也增加。无论污染水平如何，水稻中镉的积累顺序为根＞茎≈叶＞稻谷＞糙米，鱼类中镉的积累顺序为肝脏≈肠道＞肾脏＞鳃＞肌肉。添加鱼类后，溶解氧（DO）和水体透明度显著降低。鱼类中镉的积累趋势与水中镉浓度的变化相关（P＜0.05）。根据食品法典委员会（CAC）规定的糙米中镉的最大限量（0.40毫克/千克）和鱼肉中镉的最大限量（0.10毫克/千克），计算得出土壤镉对水稻和鱼类的安全阈值分别为5.86毫克/千克和31.47毫克/千克，这表明在镉污染的稻鱼共生系统中，水稻面临的安全风险要大得多。
