The risks of sulfur addition on cadmium accumulation in paddy rice under different water-management conditions  

作　　者：Zhe Liu Qi-qi Wang Si-yu Huang Ling-xuan Kong Zhong Zhuang Qi Wang Hua-fen Li Ya-nan Wan 

机构地区：[1]Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation,Key Laboratory of Plant-Soil Interactions of the Ministry of Education,College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193,China

出　　处：《Journal of Environmental Sciences》2022年第8期101-111,共11页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 41907146)。

摘　　要：Recently, the application of sulfur(S) has been recommended to control the accumulation of cadmium(Cd) in rice in contaminated paddy soil. However, the effects of exogenous S on Cd transfer in paddy rice systems under different water-management practices have not been systematically investigated. Pot experiments were performed to monitor the composition of soil pore water and the Cd accumulation in iron plaque and rice tissue were compared under different S(0 and 200 mg/kg Na_(2)SO_(4)) and water(continuous and discontinuous flooding) treatments. Sulfur application significantly increased Cd concentrations in soil pore water under discontinuous flooding conditions, but slightly reduced them under continuous flooding. Moreover, the oxidation/reduction potential(Eh) was the most critical factor that affected the Cd levels. When the Eh exceeded-42.5 mV, S became the second critical factor, and excessive S application promoted Cd dissolution. In addition, S addition elevated the Cd levels in iron plaque and reduced the Cd transfer from the iron plaque to rice roots. In rice, S addition inhibited Cd transfer from the rice roots to the straw;thus, more Cd was stored in the rice roots. Nevertheless, additional S application increased the Cd content in the rice grains by 72% under discontinuous flooding, although this effect was mitigated by continued flooding. Under simulated practical water management conditions, S addition increased the risk of Cd contamination in rice, suggesting that S application should be reconsidered as a paddy fertilization strategy.

关 键 词：Rice CADMIUM SULFUR Water management Iron plaque ACCUMULATION 

分 类 号：X173[环境科学与工程—环境科学]