Effects Of Nitrogen Fertilizer And Phosphate Fertilizer On The Concentration Of Cu In Leersia Hexandra Swartz And Its Physiological Response

Leersia Hexandra Swartz was found in southern part of China for the first time,and the experiment found that L.Hexandra can also achieve the effect of super-enrichment of heavy metal copper.Fertilization is an important measure to increase soil fertility and crop yield in agricultural agro-production activities.Different forms of nitrogenous and phosphorous fertilizers were applied to the soil to investigate its effects on the growth and copper enrichment of L.Hexandra,and the effects of different nitrogen fertilizers on the regeneration capacity of L.Hexandra,aiming at providing reference for the application of nitrogenous fertilizer and phosphate fertilizer to the enrichment of heavy metals and remediation of contaminated soil.When the copper contents in the soil were low,medium,and high?100,300 and 500mg/kg?,?NH₄?₂SO₄,CO?NH₂?₂,Ca?NO₃?₂ and NH₄NO₃ had different effects on the Cu accumulation in the hyperaccumulator and the plant growth..When the Cu content of the soil is 500mg/kg,he Cu enrichment in the root,stems and leaves of the L.Hexandra treated by Ca?NO₃?₂ were the largest,which were 6167.15,1251.99 and 975.92mg/kg,was about 2.5-4 times of Cu enrichment in control group,and was significantly different from other treatment and control group.The plant height and biomass of L.Hexandra in the treatment group of?NH₄?₂SO₄ were significantly higher than those in other treatment groups.The chlorophyll,soluble protein and Metallothionein of L.Hexandra in Group of CO?NH₂?₂ ere higher than those of other treatment groups,while the MDA of treatment Group of NH₄NO₃ was least malondialdehyde,which relieved the toxicity of Cu to L.Hexandra.When the copper contents in the soil were low,medium,and high?100,300,and 500mg/kg?,different forms of phosphate fertilizers,such as Ca?H₂PO₄?₂?KH₂PO₄ and?NH₄?₂HPO₄were tested for the Cu accumulation in the hyperaccumulator,the effects of plant growth and physiological responses,and it was sure that the best type of phosphate fertilizer that could increase copper enrichment in L.Hexandra beetles.The results showed that the concentration of Cu in the root,stem and leaf of the treatment group of the Ca?H₂PO₄?₂ was the largest in the soil with high concentrations of Cu,which were 2247.343,1369.194 and 871.2767mg/kg respectively,about 1.6 times the control group.The plant height and biomass of the KH₂PO₄and?NH₄?₂HPO₄ treatment group were higher than those of the other groups,reaching 68.27,61.07,87cm and 9.20,9.84,8.19g/?10 strains?.Therefore,different phosphate fertilizers have different effects on the growth and enrichment of cu in L.Hexandra.When the contents of Cu in soil were 0,100,200,300 and 500mg/kg,the effect of ammonium nitrogen and nitrate nitrogen on the regeneration ability of L.Hexandra was different,which was reflected in the biomass,chlorophyll,root and nitrate content of the regenerated leaves.There was no significant effect on the accumulation and biomass yield of the cu in L.Hexandra on the continuous harvesting of the aboveground part?p>0.05?.The biomass of L.Hexandra and the cumulative amount of Cu in the nitrogen fertilizer treatment group were significantly affected?P<0.05?,and the different nitrogen forms had different effects on the regeneration ability of L.Hexandra.