| In the experiment, seven passivators were set up with biochar(BC), meerschaum(SEP), bentonite(BE), Po wisp(PA), humic acid(HA), sodium silicate(SS), and manganese sulfate(MN), and a two-year field test was carried out with no passivator as the control(CK). By analyzing wheat yield, biomass, organ enrichment coefficient and transport coefficient, the passivation effect of different passivators on mild-to-moderate Cd polluted farmland in Hetao irrigation area was explored. The results showed that from 2020 to 2021, the yield of SEP and SS increased significantly compared with that of CK, with an increase rate of 11.09%-81.49%; and the biomass of each part increased by different degrees, and the weight of grain and root increased significantly. The Cd content of leaves was significantly reduced by 26.75% under SS treatment and the Cd content of grain was significantly reduced by 47.62% under SEP treatment. The Cd enrichment coefficient of each part under the passivator treatment was less than 1. The Cd transport coefficients showed that the root to leaf transport was the highest. The Cd content of wheat grain was significantly positively correlated with the Cd enrichment coefficient in stem, and the Cd transport coefficient from stem to leaf and from root to panicle. Principal component analysis showed that the Cd enrichment coefficient of stem had a positive effect on the enrichment of Cd content in grain, and Cd had the greatest influence on Cd content in the transport process from ear to grain and from stem to leaf. SEP and SS not only increased wheat yield, but also reduced the Cd content in the plant, and inhibited the transport and enrichment of Cd in the plant. The application of sodium silicate and sepiolite can be considered to achieve the purpose of the contaminated farmland safety due to mild to moderate Cd pollution in the Hetao Irrigation Area of Inner Mongolia. |
基本信息
