Toxic effects of the elution from the different feedstock biochars on seeds germination and seedling growth of radish
[Objective]This study,with an investigation of the toxic effects of biochar on seed germination and seedling growth,is aimed to provide a theoretical basis for the potential screening of typical organic waste carbonization in agriculture and the safe use of dosage,which is conducive to the safe application of biochar in agriculture.[Method]With kitchen waste biochar(KB),pig manure biogas digestion residues derived biochar(PB),and rice straw biochar(RB),chosen as the raw materials and the control group treated with deionized water,an assessment was conducted of the influence of biochar extracts with different solid-liquid ratios(1∶20,1∶50,1∶100,m/V)on seed germination and seedling growth of radish(Raphanus sativus).[Result]Compared with the control without biochar extracts,the biochar extracts with the solid-liquid ratio of 1∶100 have no significant effect on radish seed germination and seedling growth but those with the solid-liquid ratio of 1∶20 and 1∶50 inhibit the radish seed germination significantly(P＜0.05).The seedling fresh weight,root length,and seedling length cultured by biochar extracts with a 1∶50 solid-liquid ratio were reduced by 29.55％-51.89％,20.77％-76.04％,and 37.73％-56.01％,respectively,indicating a significant growth inhibition effect of biochar extracts(P＜0.05).When cultured with 1∶20 biochar extract,the survival rate of radish seedlings was lower than 12％.The inhibitory effects of different kinds of biochar reduced in the following order:kitchen waste biochar＞rice straw biochar＞pig manure biogas digestion residues derived biochar.The pH,total concentration of inorganic salts,As,Na,and K concentration of the extract solution were negatively correlated with radish seed germination and seedling growth(P＜0.05)and served as the main factors inhibiting radish growth.The root activity of radish seedlings cultured with the 1∶50 solid-to-liquid ratio decreased whereas the content of malondialdehyde(MDA)increased,indicating the destruction of seedling root cell membranes and the occurrence of resultant lipid peroxidation.[Conclusion]The biochar extracts with a high solid-liquid ratio(＞1∶50,m/V)had toxic effects on radish seed germination and seedling growth.[Ch,3 fig.4 tab.29 ref.]
万方数据
维普
