NH<sub>4</sub><sup>+</sup>-N and Low Ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N Promote the Remediation Efficiency of <i>Salix linearistipularis</i> in Cd- and Pb-Contaminated Soil
(1) Background: the utilization of fast-growing trees for phytoremediation in heavy-metal-contaminated soil is increasingly recognized as an effective remediation method. Nitrogen (N) fertilizer enhances plant tolerance to heavy metals, yet the impact of various N levels and ammonium (NH<sub>4...
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MDPI AG
2024-02-01
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| Series: | Forests |
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| Online Access: | https://www.mdpi.com/1999-4907/15/3/419 |
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| author | Dongliu Di Shaokun Wang Guangcai Chen Qian Wang Jingwei Zhang Xiaoyun Niu Dazhuang Huang |
| author_facet | Dongliu Di Shaokun Wang Guangcai Chen Qian Wang Jingwei Zhang Xiaoyun Niu Dazhuang Huang |
| author_sort | Dongliu Di |
| collection | DOAJ |
| description | (1) Background: the utilization of fast-growing trees for phytoremediation in heavy-metal-contaminated soil is increasingly recognized as an effective remediation method. Nitrogen (N) fertilizer enhances plant tolerance to heavy metals, yet the impact of various N levels and ammonium (NH<sub>4</sub><sup>+</sup>-N)/nitrate (NO<sub>3</sub><sup>−</sup>-N) ratios on the remediation of cadmium (Cd) and lead (Pb) by trees remains unclear. (2) Methods: the efficiency of <i>Salix linearistipularis</i> in remediating Cd- and Pb-contaminated soil was investigated using a pot experiment with three N levels (60, 120, 200 kg hm<sup>−1</sup> year<sup>−1</sup>) and five NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N ratios (6/0, 4/2, 3/3, 2/4, 0/6) employed, resulting in 16 treatments including a control. (3) Results: the levels and ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N significantly affected the Cd and Pb uptake by <i>S. linearistipularis</i>. The highest increases in Cd and Pb in <i>S. linearistipularis</i> were observed for the N<sub>120</sub>-6/0 treatment, which increased by 104.36% and 95.23%, respectively. In addition, in the N<sub>120</sub>-6/0 treatment, the stem and leaf bioconcentration factors of Cd were significantly enhanced by 28.66% and 40.11%, respectively. Structural equation modeling revealed that the uptake of Cd and Pb was predominantly influenced by plant traits (biomass and root traits) rather than soil properties. (4) Conclusions: Our findings highlight the potential of the NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N ratio to regulate plant traits, thereby improving the phytoremediation efficiency of heavy-metal-contaminated soil. |
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| spelling | doaj.art-e1cb5a24f7c6437282d42eceb9fa32192024-03-27T13:41:31ZengMDPI AGForests1999-49072024-02-0115341910.3390/f15030419NH<sub>4</sub><sup>+</sup>-N and Low Ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N Promote the Remediation Efficiency of <i>Salix linearistipularis</i> in Cd- and Pb-Contaminated SoilDongliu Di0Shaokun Wang1Guangcai Chen2Qian Wang3Jingwei Zhang4Xiaoyun Niu5Dazhuang Huang6College of Landscape Architecture and Tourism, Hebei Agricultural University, Baoding 071001, ChinaCollege of Landscape Architecture and Tourism, Hebei Agricultural University, Baoding 071001, ChinaResearch Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, ChinaCollege of Landscape Architecture and Tourism, Hebei Agricultural University, Baoding 071001, ChinaCollege of Landscape Architecture and Tourism, Hebei Agricultural University, Baoding 071001, ChinaCollege of Landscape Architecture and Tourism, Hebei Agricultural University, Baoding 071001, ChinaCollege of Landscape Architecture and Tourism, Hebei Agricultural University, Baoding 071001, China(1) Background: the utilization of fast-growing trees for phytoremediation in heavy-metal-contaminated soil is increasingly recognized as an effective remediation method. Nitrogen (N) fertilizer enhances plant tolerance to heavy metals, yet the impact of various N levels and ammonium (NH<sub>4</sub><sup>+</sup>-N)/nitrate (NO<sub>3</sub><sup>−</sup>-N) ratios on the remediation of cadmium (Cd) and lead (Pb) by trees remains unclear. (2) Methods: the efficiency of <i>Salix linearistipularis</i> in remediating Cd- and Pb-contaminated soil was investigated using a pot experiment with three N levels (60, 120, 200 kg hm<sup>−1</sup> year<sup>−1</sup>) and five NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N ratios (6/0, 4/2, 3/3, 2/4, 0/6) employed, resulting in 16 treatments including a control. (3) Results: the levels and ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N significantly affected the Cd and Pb uptake by <i>S. linearistipularis</i>. The highest increases in Cd and Pb in <i>S. linearistipularis</i> were observed for the N<sub>120</sub>-6/0 treatment, which increased by 104.36% and 95.23%, respectively. In addition, in the N<sub>120</sub>-6/0 treatment, the stem and leaf bioconcentration factors of Cd were significantly enhanced by 28.66% and 40.11%, respectively. Structural equation modeling revealed that the uptake of Cd and Pb was predominantly influenced by plant traits (biomass and root traits) rather than soil properties. (4) Conclusions: Our findings highlight the potential of the NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N ratio to regulate plant traits, thereby improving the phytoremediation efficiency of heavy-metal-contaminated soil.https://www.mdpi.com/1999-4907/15/3/419willownitrogenheavy metalsphytoremediationplant traitsoil contamination |
| spellingShingle | Dongliu Di Shaokun Wang Guangcai Chen Qian Wang Jingwei Zhang Xiaoyun Niu Dazhuang Huang NH<sub>4</sub><sup>+</sup>-N and Low Ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N Promote the Remediation Efficiency of <i>Salix linearistipularis</i> in Cd- and Pb-Contaminated Soil Forests willow nitrogen heavy metals phytoremediation plant trait soil contamination |
| title | NH<sub>4</sub><sup>+</sup>-N and Low Ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N Promote the Remediation Efficiency of <i>Salix linearistipularis</i> in Cd- and Pb-Contaminated Soil |
| title_full | NH<sub>4</sub><sup>+</sup>-N and Low Ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N Promote the Remediation Efficiency of <i>Salix linearistipularis</i> in Cd- and Pb-Contaminated Soil |
| title_fullStr | NH<sub>4</sub><sup>+</sup>-N and Low Ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N Promote the Remediation Efficiency of <i>Salix linearistipularis</i> in Cd- and Pb-Contaminated Soil |
| title_full_unstemmed | NH<sub>4</sub><sup>+</sup>-N and Low Ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N Promote the Remediation Efficiency of <i>Salix linearistipularis</i> in Cd- and Pb-Contaminated Soil |
| title_short | NH<sub>4</sub><sup>+</sup>-N and Low Ratios of NH<sub>4</sub><sup>+</sup>-N/NO<sub>3</sub><sup>−</sup>-N Promote the Remediation Efficiency of <i>Salix linearistipularis</i> in Cd- and Pb-Contaminated Soil |
| title_sort | nh sub 4 sub sup sup n and low ratios of nh sub 4 sub sup sup n no sub 3 sub sup sup n promote the remediation efficiency of i salix linearistipularis i in cd and pb contaminated soil |
| topic | willow nitrogen heavy metals phytoremediation plant trait soil contamination |
| url | https://www.mdpi.com/1999-4907/15/3/419 |
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