Effects of electrolytic manganese residue and phosphogypsum composite substrates on seed germination and seedling growth of Miscanthus
The energy plant Miscanthus was used as the material,a petri dish experiment were used to investigate the effect of electrolyt-ic manganese residue and phosphogypsum compound on seed germination and seedling growth of Miscanthus.Phosphogypsum was added to electrolytic manganese residue at a total mass of 5%,10%,15%,20%,and 25%to form a mixed matrix.Pure electrolytic manga-nese residue and pure phosphogypsum were used as controls.The results showed that the germination rates of Miscanthus seeds in this study ranged from 77.78%to 94.44%,and the differences were not significant among the treatments except for 5%phosphogypsum treatment.The mass proportion of phosphogypsum in the composite matrix was from 15%to 25%,with the highest germination potential and germination index.Compared with electrolytic manganese residue alone and phosphogypsum alone as substrate,the compounding of the two significantly promoted the growth of Miscanthus seedlings,which increased their shoot fresh weights by 12.50%to 30.68%and 22.22%to 41.98%,respectively.At the same time,the compounded substrates also increased the chlorophyll a and total chlorophyll contents and decreased the malondialdehyde(MDA)content.The fuzzy membership function analysis results showed that the average score was highest when the mass ratios of electrolytic manganese residue and phosphogypsum in the composite matrix were 85%and 15%,respectively,which was more suitable for the growth of Miscanthus.This study could provide a basis for the cultivation of energy plants and the environmental protection of manganese and phosphorus mining areas.