有机物料与NPK配施对多重金属污染土壤及甜高粱生长生理的影响

Effects of Combined Application of Organic Material and NPK on Multiple Heavy Metals Polluted Soil and Growth Physiological Characteristics of Sweet Sorghum

【目的】了解多重金属污染土壤在外源有机物料配施化学肥料处理后对土壤重金属形态变化以及甜高粱苗期生长和生理特性的影响,为重金属污染土壤修复提供科学依据。【方法】以甜高粱为研究对象,采用盆栽试验的方法,研究在多重金属污染土壤中施加不同添加量的秸秆、有机肥和生物质炭,并配施氮磷钾肥处理下,土壤中重金属形态、甜高粱苗期植株生长及生理指标的变化趋势。【结果】有机肥和生物质炭分别与NPK配合处理能显著降低土壤中重金属有效态含量,其随着各处理施用量的增加而减少。秸秆配合NPK处理后土壤中铅(Pb)、锌(Zn)及镉(Cd)的有效态含量先增后减。随着外源有机物料施用量不断增加,甜高粱苗期的株高和生物量呈增长趋势,过氧化物酶(POD)和超氧化物歧化酶(SOD)活性提高。有机肥和生物质炭施用量越高,叶绿素(Chl)含量越高,丙二醛(MDA)含量越低。【结论】外源有机物料配施NPK能有效降低土壤中重金属有效态含量,进而降低对甜高粱的毒害作用,增强酶活性。处理中以有机肥配施NPK在降低多金属污染土壤效果最好。

【Objective】The present paper was conducted to evaluate the changes of heavy metals morphologic in soil and the effect of multiple heavy metal pollution on the sweet sorghum seedling after applying organic material with NPK fertilizer,provide a scientific basis for the remediation of heavy metal contaminated soils.【Method】Sweet sorghum was used as research object,pot experiments were conducted to study the different amounts of straw,organic fertilizer and biochar with NKP fertilizer on speciation of heavy metals and the growth and physiological indexes of sweet sorghum seedlings.【Result】The organic fertilizer and straw biochar treated with NPK could significantly reduce the effective content of heavy metals in soil,and decreased with the increase of treatment amounts.However,the extractable content of Pb,Zn,Cd in soil increased first and then decreased after the treatment of straw with NPK.With the increase of exogenous organic materials application,the plant height and biomass of sweet sorghum seedlings continued to increase,also improved peroxidase（POD） and superoxide dismutase（SOD） activity,and reduced the toxicity of heavy metals to sweet sorghum.The larger the amount of organic materials was,the larger the content of chlorophyll（Chl） became and the lower the content of malondialdehyde（MDA） became.【Conclusion】Adding organic materials with NPK treatments could reduce the effective content of heavy metals in soils,decrease the toxic effects on sweet sorghum,and increase enzyme activity.In particular,the application of organic fertilizer with NPK to reduce the effect of soil by multiple heavy metals contaminated was the best.