Effects of nutria-amendment on the biomass and cadmium uptake of Oryza Sativa grown in vegetative soil
A pot experiment was conducted in 2014,to investigate the effects of a nutria-amendment[0(CK),1.5(T1),3.0(T2),4.5 g·kg-1(T3),and 6.0 g·kg-1(T4)]on the growth and cadmium(Cd)uptake by Oryza Sativa L.grown in vegetative soil with a Cd concentration over its screening standard.The results showed that compared with the control,the nutria-amendment failed to promote the growth of the whole rice plant,and to increase rice yield.The order of Cd concentrations in the rice tissues from large to small was root>straw>brown rice>husk,with a significant difference among the four rice tissues(P<0.05).Cd concentrations of brown rice in treatments were all below the national standard value of 0.2 mg·kg-1.In contrast with the control,the nutria-amendment significantly decreased Cd concentrations in brown rice,rice straw,and rice root,with the highest concentration decrease of 32.8%,39.7%,and 24.4%observed under the T4 treatment,respectively.Moreover,the higher the dosage of nutria-amendment,the better the effect was on Cd concentration decrease in rice tissues.The nutria-amendment markedly increased the soil pH with the biggest increase of 0.3 units under the T4 treatment,and increased soil DTPA-Cd concentrations(DTPA-Cd concentrations of the T1 treatment were significantly bigger than those of CK and T3),while reducing soil available Si concentrations of the T2 and T3 treatments were significantly lower than those of CK.Therefore,the nutria-amendment owing to its ability to decrease the Cd bioconcentration factor in the rice root tissues,is suitable for application to the tested vegetative soil with a Cd concentration above its screening standard.Furthermore,the 6 g per 1 kg of vegetative soil was the efficient nutria-amendment dose in the pot experiment to obtain a lower Cd concentration in brown rice.
万方数据
维普
