College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China; Hunan Engineering Laboratory for Control of Rice Quality and Safety, Central South University of Forestry and Technology, Changsha, 410004, China.
College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China; Hunan Engineering Laboratory for Control of Rice Quality and Safety, Central South University of Forestry and Technology, Changsha, 410004, China.
Ecotoxicol Environ Saf. 2020 Jun 1;195:110492. doi: 10.1016/j.ecoenv.2020.110492. Epub 2020 Mar 20.
A pot experiment was conducted to evaluate the effects of combined application of cadmium (Cd)-resistant bacteria (J) and calcium carbonate + sepiolite (G) on both Cd bioavailability in contaminated paddy soil and on Cd accumulation in rice plants. Adding the mixture (J + G) to the soils significantly increased soil pH, decreased extractable Cd contents, and increased Fe/Mn-oxide Cd and organic-bound Cd contents. The applying of J + G, J and G decreased Cd contents in various rice tissues (roots, stems and leaves, husks, and brown rice grains) to different degrees. Compared with those of the CK, Cd contents decreased by 17.8%-53.3% in the roots, 12.3%-27.4% in the stems and leaves, 25.4%-44.6% in the husks, and 28.8%-55.7% in the brown rice grains for the application of J + G; Cd contents decreased by 8.2%-28.5% in the roots, 11.5%-32.0% in the husks, and 27.8%-45.9% in the brown rice grains for the application of J; Cd contents decreased by 12.9%-26.5% in the roots, in the stems and leaves decreased by 4.6%-34.1% in the stems and leaves, 60.2%-79.7% in the husks, and 35.7%-47.6% in the brown rice grains for the application of G. The alone application of bacteria (J) could reduce the bioavailability of Cd in soil and the contents of Cd in brown rice grains to some extent. Moreover, when the bacteria were applied in combination with mineral (J + G), it was a more effective method than the alone application of J or G to reduce the soil Cd bioavailability. Under all the tested conditions, applications of J4+G4 (320 mL kg of J + 8 g kg of G) resulted in the greatest reduction in Cd contents in brown rice grains. Overall, the results indicated that the combination of Cd-resistant bacteria and mineral material could effectively reduce Cd bioavailability in paddy soils and inhibit Cd accumulation in brown rice grains.
采用盆栽试验研究了镉（Cd）抗性细菌（J）和碳酸钙+海泡石（G）联合施用对污染稻田土壤中 Cd 生物有效性和水稻植株 Cd 积累的影响。向土壤中添加混合物（J+G）可显著提高土壤 pH 值，降低可提取 Cd 含量，并增加 Fe/Mn 氧化物结合态 Cd 和有机结合态 Cd 含量。与对照相比，J+G、J 和 G 的施用使水稻各部位（根、茎和叶、壳和糙米）的 Cd 含量不同程度降低。与对照相比，J+G 的施用使根中 Cd 含量降低了 17.8%-53.3%，茎和叶中降低了 12.3%-27.4%，壳中降低了 25.4%-44.6%，糙米中降低了 28.8%-55.7%；J 的施用使根中 Cd 含量降低了 8.2%-28.5%，壳中降低了 11.5%-32.0%，糙米中降低了 27.8%-45.9%；G 的施用使根中 Cd 含量降低了 12.9%-26.5%，茎和叶中降低了 4.6%-34.1%，壳中降低了 60.2%-79.7%，糙米中降低了 35.7%-47.6%。单独施用细菌（J）可以在一定程度上降低土壤 Cd 的生物有效性和糙米中 Cd 的含量。此外，当细菌与矿物（J+G）联合施用时，与单独施用 J 或 G 相比，降低土壤 Cd 生物有效性的效果更为显著。在所有测试条件下，施用 J4+G4（320 mL kg 的 J+8 g kg 的 G）可使糙米中 Cd 含量降低最多。总体而言，结果表明，Cd 抗性细菌与矿物材料的结合可有效降低稻田土壤中 Cd 的生物有效性，抑制糙米中 Cd 的积累。
