| As a unique genotype of Solanum alatum in arid area,Solanum alatum hasstrong tolerance to Cd and can be used for remediation of Cd-contaminated soil.Due to the relatively poor soil in arid areas,the bioavailability of nutrients needed by plants is low.Moreover,as an annual herb,the growth of Solanum alatum will directly affect the remediation efficiency of Cd-contaminated soil.Therefore,this paper studied the agronomic enhancement measures for the remediation of Cd-contaminated calcareous soil by Solanum alatum with Solanum alatum as the test plant and Cd-contaminated calcareous soil in the arid area.In this study,greenhouse pot experiment was carried out,and three different agronomic measures（nitrogen fertilizer,iron fertilizer,and growth regulator）were used to strengthen the remediation of the Cd contaminated soil by the Solanum alatum,providing a basis for the remediation of the Cd contaminated calcareous soil by the Solanum alatum in the arid area.Through the analysis of the interaction and changes among the growth index,physiological index and soil composition index of Solanum alatum after maturity,the following conclusions were drawn:（1）The addition of nitrogen fertilizer significantly increased the biomass of Solanum alatum,in which the application of urea at the concentration of 150 mg kg-1increased the biomass of Solanum alatum most significantly,which increased by 211.96%compared with the control group.Moreover,the promotion effect of compound nitrogen fertilizer NH4NO3 on the growth of Solanum sinensis was better than that of single nitrogen fertilizer.Single application of ammonium nitrogen can promote the enrichment of Cd in the leaves of Solanum alatum,single application of nitrate nitrogen could promote the enrichment of Cd in the stem of Solanum alatum.However,the application of urea had little promoting effect on the Cd enrichment ability of various organs of Solanum alatum,but it had the largest promoting effect on the biomass,so the application of urea was the best to promote the restoration of Cd in soil of Solanum alatum.The maximum value was reached when the urea concentration was 300 mg kg-1,which increased by 158.76%compared with the control group.（2）The application of iron fertilizer also significantly increased the biomass of Solanum alatum.The addition of 0.2 m M Fe SO4 soil treatment had the most significant promoting effect on the biomass of Solanum alatum,which increased by265.22%compared with the control group.The 2 m M EDTA-Fe spraying treatment promoted the enrichment of Cd in leaves,while the 8 m M EDTA-Fe spraying treatment promoted the enrichment of Cd in stems.Compared with the control group,8 m M EDTA-Fe spraying treatment had the highest accumulation of Cd,which increased by276.46%,indicating that EDTA-Fe spraying at high concentration had the best strengthening effect on the remediation of Cd-contaminated calcareous soil by Solanum alatum.Iron fertilizer applied to promote the Cd from the roots to the ground part of transhipment,promoted the Solanum alatum aboveground enrichment of Cd,under the four processing iron fertilizer on soil effective Cd content has increased significantly,but did not promote the absorption of Solanum alatum on Cd,The increase of available Cd content may cause environmental pollution,so it is necessary to avoid the impact of heavy metal activation on the environment while carrying out phytoremediation.（3）The addition of growth regulators increased the biomass of Solanum alatum,which significantly promoted the growth of Solanum alatum.Compared with the control group,5 mg L-1 chlorfenuron treatment had the most significant biomass increase,which was 111.46%,while 5mg L-16-benzylaminopurine treatment had the least biomass increase,which was 22.29%compared with the control group.Different growth regulators promoted the enrichment of Cd in the root of Solanum alatum,especially in the treatment of sodium nitrophenate.However,the transport of Cd from root to aboveground was inhibited by the growth regulators.Among all the growth regulator treatments,20 mg L-1 gibberellin treatment had the most significant promoting effect on the accumulation of Cd,which increased by 107.48%compared with the control group,indicating that 20mg L-1 gibberellin treatment was the most effective in promoting the accumulation of Cd.In conclusion,the application of agronomic measures can significantly improve the accumulation ability of Cd and enhance the remediation ability of the Cd-contaminated calcareous soil of Solanum alatum,which provides a theoretical basis for the phytoremediation of the Cd-contaminated calcareous soil in arid areas. |
