不同钝化材料对弱酸性稻田稻米吸收镉的影响

为了找到适宜弱酸性镉轻度污染稻田应用的钝化材料及用量,通过田间小区试验设置不同钝化材料处理,探究其对弱酸性镉（Cd）轻度污染稻田（pH值范围6.1~6.5）土壤pH值、全Cd含量、有效态Cd含量、稻米Cd含量及水稻产量的影响。研究结果表明：与CK相比,施加0.1%生石灰、0.3%微米羟基磷灰石、0.3%洁地保土壤调理剂均显著提升土壤pH值,分别提高了约0.86、0.66、0.28个单位,使土壤环境由弱酸性向中性过渡或转变为中性;各处理土壤全Cd含量无显著性差异,0.1%生石灰、0.3%微米羟基磷灰石、0.5%稻壳生物炭、0.3%洁地保土壤调理剂处理土壤有效态Cd含量均显著降低（P<0.05）,下降率分别为20.08%、20.92%、13.99%、20.60%;各处理稻米Cd含量均显著降低22.02%~72.80%,均符合《食品安全国家标准食品中污染物限量》（GB 2762-2017）,降Cd效果显著,其中0.1%生石灰、0.3%微米羟基磷灰石、0.3%洁地保土壤调理剂处理稻米Cd降Cd率均在60%以上;各处理水稻产量均无显著差异,且小幅增产1.23%~6.13%。结合适宜水稻生长发育的土壤pH值范围、综合考虑钝化材料长效稳定性,建议施用0.3%微米羟基磷灰石或0.3%洁地保土壤调理剂。研究结果可为今后指导弱酸性Cd轻度污染稻田原位钝化修复技术的应用与研究提供一定的科学依据和理论基础。

Effects of different immobilization materials on absorption of rice cadmium in weakly acidic paddy fields

In order to find suitable immobilization materials and dosages for the application of weakly acidic cadmium lightly polluted paddy fields, different immobilization materials treatments were set up through field experiments to explore their effects on soil pH, total Cd content, available Cd content, rice Cd content and rice yield of weakly acidic cadmium (Cd) in mildly polluted rice fields (pH range 6.1-6.5). The results showed that compared with CK treatment, the application of 0.1% quicklime, 0.3% micron hydroxyapatite, and 0.3% soil cleaning agent significantly increased the soil pH value by about 0.86, 0.66, and 0.28 units, respectively, causing the soil environment to transition from weakly acidic to neutral or to neutral; there was no significant difference in total soil Cd content among treatments, and the soil available Cd content in the conditioner treatments with 0.1% quicklime, 0.3% micro-hydroxyapatite, 0.5% rice husk biochar and 0.3% clean soil conservation were significantly decreased (P<0.05), with a decrease rate of 20.08%, 20.92%, 13.99%, and 20.60%, respectively; the Cd content of rice was significantly decreased by 22.02%-72.80% in each treatment, , which were in accordance with the "National Food Safety Standard Limits of Contaminants in Food" (GB 2762-2017) , and the Cd reduction effect was significant, in which the Cd reduction rate of rice treated with 0.1% quicklime, 0.3% micron hydroxyapatite, and 0.3% clean soil conditioner were above 60%;there was no significant difference in rice yield among all