Influence of nitrogen forms and application rates on the phytoextraction of copper by castor bean (Ricinus communis L.)
2020
Zhou, Xiupei | Huang, Guoyong | Liang, Ding | Liu, Yonghong | Yao, Shiyuan | Ali, Umeed | Hu, Hongqing
Fertilization is an important agricultural strategy for enhancing the efficiency of phytoremediation in copper (Cu)-contaminated soils. In this study, the effects of nitrogen (N) forms, including ammonium (NH₄⁺-N) and nitrate (NO₃⁻-N), on the growth, translocation, and accumulation of Cu in the tissues of Ricinus communis L. were investigated in pot and hydroponic experiments. The results demonstrated that higher biomass and N contents in plants were obtained when N was supplied as NO₃⁻-N rather than NH₄⁺-N. Application of N increased the Cu content in the roots of R. communis, with a higher content after NH₄⁺-N (53.10–64.20 mg kg⁻¹) than NO₃⁻-N (37.62–53.75 mg kg⁻¹) treatment. On the contrary, the levels of Cu translocation factors were much higher in NO₃⁻-fed plants (0.34–0.45) than in NH₄⁺-fed plants (0.28–0.38). The suggested amount of N for fertilizer application is 225 kg hm⁻², which resulted in the highest Cu content in R. communis and optimal plant growth. As the main Cu-binding site, root cell walls accumulated less Cu in plants treated with NH₄⁺-N compared with NO₃⁻-N. Additionally, NH₄⁺-N induced a higher malondialdehyde content and more severe root damage compared with NO₃⁻-N. In the leaf, a larger number of black granules, which could be protein and starch grains involved in the detoxification of Cu in R. communis, were present after NH₄⁺-N than NO₃⁻-N treatment. These results illustrate that N forms are especially important for Cu translocation and accumulation and that immobilization and transformation of Cu in roots were improved more by NH₄⁺-N than NO₃⁻-N. In conclusion, N fertilizers containing the appropriate forms applied at suitable rates may enhance the biomass and Cu accumulation of R. communis and thereby the remediation efficiency of Cu-contaminated soils.
Afficher plus [+] Moins [-]Mots clés AGROVOC
Informations bibliographiques
Cette notice bibliographique a été fournie par National Agricultural Library
Découvrez la collection de ce fournisseur de données dans AGRIS