The effect of Cu concentration in soil and phosphorous fertilizer on plant growth and Cu uptake by Brassia juncea L. grown on contaminated soils

Abstract

An experiment was carried out in the greenhouse conditions with Brassica juncea L. grown on alluvial soils that had previously been contaminated at different concentrations of Cu. The main purposes of the research were to determine the effects of Cu and phosphorus applications on plant growth and Cu uptake by Brassica juncea L. Mature plants were harvested for the Cu accumulation analysis. The soil samples from each growing pot were extracted by HNO3 0.43N in order to determine the content of Cu2+ mobilization in soil, while the plant samples were acid digested for determining the total Cu concentration. Atomic Absorption Spectroscopy (AAS) was employed to determine Cu concentrations in soils and plant samples. The results showed that adding Cu to soils has strong effects on Brassica juncea L. growth and the uptake rate of Cu by the plants. The height and the biomass of plants were reduced dramatically by 36% and 53% respectively at the rate of 200 ppm Cu. In addition, phosphorous fertilizer also effectively improved plant growth and reduced Cu concentrations in plant of Brassica juncea. At the application rate of 100 kg P2O5/ha, the height and biomass of plant were increased to 30% and 31% respectively, and the Cu content in plants of Brassica juncea was reduced by 14% comparing with the control samples.