Growth and heavy metal uptake of Sorghum Hybrid Sudangrass affected by application proportion of vermicompost with high Cu and Zn enrichment

Using pot experiments, growth and heavy metal uptake of Sorghum Hybrid Sudangrass was studied when planted in soils amended with vermicomposts enriched with Cu/Zn content. The results showed that growth of Sorghum Hybrid Sudangrass was stimulated when low vermicomposts concentration was applied whereas it was restrained when high vermicomposts concentration was applied. The Cu and Zn content increased in Sorghum Hybrid Sudangrass as vermicomposts concentration increased. The forms of Cu and Zn in soils dominantly existed as organic fraction and residual fraction at the low vermicomposts concentration, but existed as acid-extractable fraction and the reducing fraction at the high application level of vermicomposts. Correlation analysis indicated that shoot Zn content, root Cu/Zn content in Sorghum Hybrid Sudangrass was positively correlated with heavy metal fraction in vermicompost amended soils. Therefore, the 10% vermicompost addition may be feasible for field production systems.