Wang Liang, Liu Qiqing, Fu Jingyi, Xiao Yuxuan, Yang Jun, Liao Xiaoyong
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101, China; Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Beijing 100101, China.
College of Environment & Ecology, Hunan Agricultural University, Changsha, China.
Ecotoxicol Environ Saf. 2025 Jan 1;289:117453. doi: 10.1016/j.ecoenv.2024.117453. Epub 2024 Dec 7.
In response to the safety risks posed by cadmium (Cd)-contaminated rice fields worldwide, a suitable production-and-restoration strategy is required for actual agricultural practices. To investigate the remediation effects of different accumulation varieties in rapeseed-rice cropping systems and their influence on Cd migration and transportation, field experiments were conducted based on different planting combinations (FWHR, conventional rice variety (HR) monoculture under fallow; FWLR, low Cd-accumulating rice variety (LR) monoculture under fallow; LOLR, LO (low Cd-accumulating rapeseed variety)-LR rotation; LOHR, LO-HR rotation; HOLR, HO (high Cd-accumulating rapeseed variety)-LR rotation; HOHR, HO-HR rotation). The study found that a rapeseed and rice rotation with appropriate varieties could reduce the rice grain Cd content, increase rice yield, and remove soil Cd without affecting agricultural production efficiency. Compared to the fallow-conventional rice pattern, various rapeseed-rice rotations reduced the Cd content of rice grains by 15 %-38 %, and significantly increased the available potassium (Ava-K) in the subsequent rice soil by 29.6-56.4 mg/kg. The total economic benefits increased by $500-$1800 per hectare. A high accumulation variety of rapeseed and low accumulation variety of rice produced the most effective reduction in Cd levels, with a reduction rate of 38 % in brown rice and an annual removal rate of 24.42 g/hm. This combination also resulted in a 29 % increase in rice yield compared to the fallow-low accumulation variety rice pattern. Structural equation modeling revealed that with the combined action of crop rotation and variety selection the crop rotation directly reduced the soil available Cd or had an indirect effect by weakening the root-zone acidification effect and increasing soil Ava-P. The rotation of rapeseed and rice with carefully selected matching varieties is a feasible solution for the safe production and pollution remediation of Cd-contaminated paddy fields.
针对全球镉（Cd）污染稻田带来的安全风险，实际农业生产需要一种合适的生产与修复策略。为研究不同富集品种在油菜-水稻种植系统中的修复效果及其对镉迁移转化的影响，基于不同种植组合开展了田间试验（FWHR，休耕条件下常规水稻品种（HR）单作；FWLR，休耕条件下低镉积累水稻品种（LR）单作；LOLR，低镉积累油菜品种（LO）-LR轮作；LOHR，LO-HR轮作；HOLR，高镉积累油菜品种（HO）-LR轮作；HOHR，HO-HR轮作）。研究发现，选用合适品种的油菜与水稻轮作，可降低稻米镉含量，提高水稻产量，去除土壤镉，且不影响农业生产效率。与休耕-常规水稻模式相比，各种油菜-水稻轮作使稻米镉含量降低了15% - 38%，并使后续水稻土壤中的有效钾（Ava-K）显著增加了29.6 - 56.4 mg/kg。每公顷总经济效益增加了500 - 1800美元。高镉积累品种油菜与低镉积累品种水稻搭配，对降低镉含量效果最为显著，糙米镉含量降低率达38%，年去除率为24.42 g/hm。与休耕-低镉积累品种水稻模式相比，该组合还使水稻产量提高了29%。结构方程模型显示，通过作物轮作和品种选择的共同作用，作物轮作直接降低了土壤有效镉，或通过减弱根际酸化效应、增加土壤有效磷（Ava-P）产生间接影响。选用精心匹配品种的油菜与水稻轮作，是镉污染稻田安全生产与污染修复的可行解决方案。
