[Effect of Wood Vinegar on Cadmium Enrichment and Transport of Gramineous Crops in Cd-contaminated Farmland].

Abstract

To explore the effect of wood vinegar on the enrichment and transport of heavy metal Cadmium （Cd） in gramineous crops （wheat, barley, and oat） in Cd-contaminated farmland, a field plot experiment was conducted involving nine treatments. The effects of wood vinegar on the growth of gramineous crops （wheat, barley, and oat） and the enrichment and transport of Cd in crops were studied by measuring the Cd content in plants and rhizosphere of the soil. The results showed that wood vinegar increased the biomass of crops （wheat, barley, and oats biomasses were 0-6.73%, 14.45%-15.91%, and 19.48%-21.97%, respectively, P < 0.05） and the Cd content of straw （those of wheat, barley, and oat were 12.32%-45.74%, 7.02%-42.11%, and 19.90%-25.00%, respectively, P < 0.05）. On applying wood vinegar diluted 400 times, the Cd content in roots of wheat and barley decreased by 7.77% and 29.26%, respectively, and that of oats increased by 28.74%. The translocation factor （TF） root-straw of wheat and barley increased by 58.30% and 100.87%, whereas the TF straw-grain decreased significantly by 30.40% and 32.20%, respectively. The TF root-straw of oat decreased by 3.14%, whereas the TF straw-grain decreased by 21.02%. The difference in Cd content before and after planting of barley and oats was significantly higher than that of wheat at the harvest stage. Among them, the Cd content of barley D-T1 and oat E-T2 decreased by 18.53% and 19.59% compared with that before planting. Based on the comprehensive analysis of Cd accumulation, transport coefficient, and Cd content in different parts of wheat, barley, and oat, the risk coefficient of Cd content in barley grain was the lowest, which was suitable for planting in moderate and mild Cd-contaminated farmland and could be remediated during production by leaving the straw in the field to realize the safe cultivation of moderately and mildly Cd-contaminated farmland.