Lu et al. 2025 - chrysanthemums for cadmium phytoremediation
Lu and colleagues ran a two-year field trial of 23 chrysanthemum cultivars in Cd-contaminated farmland in Zhejiang Province, China. The source reports Cd in rhizosphere soil and chrysanthemum aboveground tissue, flower/stalk partitioning in multiple-cropping cultivars, bamboo-vinegar and EDTA-Si effects, and an economic estimate for remediation flower production. This is primary phytoremediation evidence, not market occurrence evidence for herbal teas or botanical supplements.
Key numbers
Site and cultivar screen
The study site was a 1 ha Cd-contaminated farmland area in a hardware-processing industrial town in Zhejiang Province. A 2020 survey found soil Cd of 0.32 mg/kg and nearly 30% rice-sample exceedance. In the trial, rhizosphere-soil Cd ranged from 0.47 to 0.96 mg/kg, with a mean of 0.65 mg/kg. The authors compare these values with the Chinese agricultural-land Cd risk-control value of 0.3 mg/kg and report a 100% exceedance rate in soil samples.
Across 23 chrysanthemum cultivars:
| Endpoint | Range | Average | Notes |
|---|---|---|---|
| Aboveground biomass | 67.10-166.08 g/plant | 111.25 g/plant | QJ-ht, marigold, JL-dc, ZS-zc, ZS-gh, and ZS-hy exceeded 140 g |
| Aboveground Cd concentration | 1.97-5.92 mg/kg | 4.45 mg/kg | Measured in aboveground plant tissue |
| Cd enrichment coefficient | 2.98-9.84 | 6.95 | QJ-hg, QJ-dh, JL-yg, JL-cj, ZS-gh, QJ-bh1, marigold, and JS-hj exceeded 8 |
| Cd accumulated per plant per season | 0.26-0.83 mg | 0.49 mg | Marigold, ZS-gh, QJ-ht, JL-cj, QJ-hg, and JL-dc exceeded 0.6 mg |
| Estimated remediation stages | 4-13 stages | 8 stages | Nine cultivars required five or fewer stages |
The authors estimated remediation time using 20 cm plant spacing, 400 cm2 area per plant, 20 cm soil depth, and 1.1 g/cm3 soil density. The cultivars with five or fewer estimated remediation stages were ZS-gh, JL-dc, JL-cj, marigold, QJ-ht, QJ-hg, ZS-hy, QL-xh, and QJ-dh.
Multiple-cropping and plant-part partitioning
Fourteen cultivars grew to full bloom after overwintering in 2022: ZS-zc, L-xf, QX-yz, QJ-hg, JH-hj, QJ-tp, QJ-bh2, QJ-dh, JL-yg, ZS-gh, JL-dc, JL-cj, JL-xy, and QJ-ht. Five cultivars had stable biomass relative to the previous year: QX-yz, QJ-hg, QJ-bh2, JL-xy, and JL-yg. For the others, reduced biomass would extend estimated rhizosphere-soil remediation by an average of 3.29 stages.
For the 14 multiple-cropping cultivars, Cd partitioned more strongly into stalks than flowers:
| Plant part | Cd concentration range | Average Cd concentration | Enrichment coefficient range | Average enrichment coefficient |
|---|---|---|---|---|
| Flowers | 1.98-4.98 mg/kg | 3.28 mg/kg | 2.67-8.94 | 5.30 |
| Stalks | 4.20-15.00 mg/kg | 8.19 mg/kg | 7.80-23.77 | 12.86 |
The authors identify stalks as the main aboveground Cd-accumulating fraction.
Bamboo vinegar and EDTA-Si test
The QX-yz cultivar was selected for chelator-enhanced phytoremediation testing because it had stable biomass and high Cd accumulation. Treatments were:
| Treatment | Preparation | Application |
|---|---|---|
| Control | Purified water | 1000 mL |
| Treatment 1 | 15 mL bamboo vinegar diluted to 4500 mL | 1500 mL |
| Treatment 2 | 15 mL bamboo vinegar diluted to 3000 mL | 1000 mL |
| Treatment 3 | 15 mg EDTA-Si diluted to 3000 mL | 1000 mL |
| Treatment 4 | 15 mL bamboo vinegar plus 15 mg EDTA-Si diluted to 6000 mL | 2000 mL |
Bamboo vinegar treatments did not significantly change biomass but increased chrysanthemum Cd concentration by 29.52 and 16.65 percentage points versus control. Cd accumulation increased by 29.63 and 34.99 percentage points in treatments 1 and 2.
EDTA-Si increased Cd concentration more strongly, with treatments 3 and 4 increasing plant Cd concentration by 97.53 and 61.02 percentage points. However, EDTA-Si reduced biomass by 62.22 percentage points in treatment 3, and treatment 4 reduced biomass by 74.85 percentage points versus control and 77.53 percentage points versus treatment 2. The authors conclude that bamboo vinegar was more useful overall because it improved Cd accumulation without the large biomass penalty. They estimate bamboo vinegar could advance QX-yz remediation by one year.
Economic estimate
The study estimated annual chrysanthemum flower yield and net income per hectare for five dominant cultivars:
| Cultivar | Flower count (hm-2 year-1) | Net income (RMB hm-2 year-1) |
|---|---|---|
| QX-yz | 3.96 x 10^6 +/- 0.42 x 10^6 | 61.67 x 10^4 +/- 9.26 x 10^4 |
| QJ-hg | 3.89 x 10^6 +/- 0.72 x 10^6 | 60.46 x 10^4 +/- 8.38 x 10^4 |
| QJ-bh2 | 4.02 x 10^6 +/- 0.86 x 10^6 | 62.69 x 10^4 +/- 11.34 x 10^4 |
| JL-xy | 3.69 x 10^6 +/- 0.41 x 10^6 | 57.03 x 10^4 +/- 7.87 x 10^4 |
| JL-yg | 4.16 x 10^6 +/- 0.58 x 10^6 | 65.09 x 10^4 +/- 10.43 x 10^4 |
| Average | 5.31 x 10^6 +/- 1.00 x 10^6 | 60.46 x 10^4 +/- 8.63 x 10^4 |
| Marigold comparison | not reported | 16.88 x 10^4 to 55.70 x 10^4 |
The narrative states that a farmer planting 0.1 ha with two crops per year could net 6.17 x 10^4 RMB, slightly above the cited Yongkang resident average annual income of 5.67 x 10^4 RMB.
Methods (brief)
Twenty-three chrysanthemum cultivars were grown from seedlings and transplanted into 12 m2 field plots in Cd-contaminated farmland. Plants were arranged in three rows at 20 cm spacing. The 2021 growing cycle ran from 10 April to 10 October. After flowering, plants were pruned to retain 10-12 cm stems and 3-4 leaves; 2022 sampling focused on multiple-cropping performance rather than simple repetition.
Three groups of chrysanthemum plants and rhizosphere soil were randomly sampled from each plot during 2021 flowering. In 2022, flowers, stalks, and rhizosphere soils were collected for multiple-cropping cultivars. Soil samples came from 0-20 cm rhizosphere soil. Flower and stalk samples were dried, weighed, and pulverized. Cd in soil and plant samples was measured by ICP-MS after HNO3-HF microwave digestion, dilution in 2% HNO3, and filtration. Soil certified reference materials were used for quality control.
Implications
Certification: Do not use this source as ordinary herbal-tea, botanical-supplement, or food-market occurrence evidence. The measured chrysanthemum tissues came from deliberate phytoremediation of contaminated farmland, and the economic channel described in the paper is mainly ceremonial flower sales.
App: Useful for contaminated-land and remediation context. If chrysanthemum flower or stalk evidence is ever considered for an herbal-botanical row, this source should be retained as a high-contamination sensitivity case, not silently pooled with retail herbal-tea evidence.
Courses: Useful for teaching how plant tissue concentrations, enrichment coefficients, removal efficiency, and economic feasibility are distinct from consumer-product occurrence and certification benchmarking.
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Verification notes
This page was built from the full PDF, including the abstract, study-site description, Tables 1-3, Figures 1-5, sampling and ICP-MS methods, remediation equations, economic estimate, conclusions, and data-availability statement. Products and ingredients are intentionally empty because the source is a contaminated-field phytoremediation trial, not a market-sampled herbal, tea, or supplement occurrence study.
Page history
The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.
| Commit | Date | Description |
|---|---|---|
| c1aef38 | 2026-06-02 | audit-queue: hamid2021-bacterial-plant-biostimulants-review → audited-promote |