Characteristics of heavy metal content in soil-Yam system under different fertilization modes
In order to explore the effects of different fertilization modes on heavy metals content in Anshun yam and its site soil,five different fertilization treatments were designed to conduct field experiments. Discarded edible fungus stick or herb of plant source were used as the raw materials,with the addition of phosphogypsum,lignite ash and other minerals,using the active amino acid fermentation method to make the fungus residue fer-mentation organic fertilizer and functional drug organic fertilizer of active amino acid,as either single-or dosed-fertilizer treatments;the contents,bioaccumulation characteristics and pollution risk levels of heavy metals in soil and plants at different growth stages were analyzed,and the degree of effect of different fertilization measures on heavy metals in yam and soil was evaluated by principal component analysis. The results showed that:(1) Different fertilization treatments significantly increased the soil heavy metal content in the tuber expansion stage,but at harvest stage,Pb,Cu and Ni decreased compared with that in pre-planting stage,while As and Cr increased significantly;the comprehensive pollution degree of heavy metals was tuber expansion stage>pre-planting stage>harvest stage,and Cd was the main pollutant. (2) Cd,Cu and Ni of yam at the harvest stage decreased significantly compared with that at the pre-planting stage,but As increased significantly. (3) The en-richment capacity of heavy metals at the tuber expansion stage was higher than that at the harvest stage,but Cr of yam at the tuber expansion stage was 0.02 and 0.14 times higher than that of control (CK) and 70％ functional drug fertilizer+30％ chemical compound fertilizer (GYF),respectively. Compared with the control,different ferti-lization treatments reduced the enrichment of heavy metals in yam to different degrees,among which the fungus residue fermentation fertilizer (JZ) treatment and 70％ fungus residue fermentation fertilizer+30％ chemical compound fertilizer (JZF) treatment were the most significant. In conclusion,the combined application of fungus residue fermentation fertilizer and chemical compound fertilizer had little effect on soil heavy metals,while the combined application of functional drug fertilizer and chemical compound fertilizer had more obvious effect on heavy metals,and the application of functional drug fertilizer or fungus residue fermentation fertilizer could alle-viate soil heavy metal pollution and reduce the accumulation of heavy metals in yam tubers to a certain extent.
fungus residue fermentation fertilizerfunctional drug fertilizeractive amino acidphosphogypsumheavy metalsbioaccumulationAnshun Yam
万方数据
维普
