Overview
This field experiment tested whether foliar sodium-selenite application reduced cadmium accumulation in brown rice grown on Cd-contaminated paddy soils in Hunan, China. Three rice cultivars were grown for three years in low-Cd and high-Cd fields, with Se treatment compared against a water control. The direct occurrence endpoint is Cd in brown rice, paired with a mitigation endpoint showing reduced Cd transfer into grain after foliar Se application.
Key numbers
Soil context (Table 1; topsoil 0-20 cm):
| Field | Total Cd (mg/kg) | Total Se (mg/kg) | pH |
|---|---|---|---|
| Low-Cd area | 0.339 | 0.243 | 5.0 |
| High-Cd area | 0.950 | 0.219 | 5.9 |
Brown-rice Cd by year (Tables 2-4; mg/kg):
| Year | Low-Cd control range | Low-Cd + Se range | High-Cd control range | High-Cd + Se range |
|---|---|---|---|---|
| 2017 | 0.530-0.797 | 0.326-0.431 | 1.018-1.729 | 0.641-1.035 |
| 2018 | 0.717-0.942 | 0.382-0.503 | 1.332-1.391 | 0.705-1.070 |
| 2019 | 0.576-0.885 | 0.315-0.516 | 1.304-1.463 | 0.698-1.062 |
Source-reported treatment effects:
- High-Cd soil increased brown-rice Cd by 91.47% compared with low-Cd soil.
- Foliar Se application decreased Cd transport from stems/leaves to spikes and reduced brown-rice Cd by 40.36% overall.
- The discussion reports stronger brown-rice Cd reduction in low-Cd soils (47.49%) than in high-Cd soils (36.37%).
- Se treatment increased rice yield by 7.58% and increased 1000-grain weight by 4.02% across 2017-2019.
- The authors state that foliar Se reduced Cd but did not reduce brown-rice Cd below the stated food-safety threshold in this Cd-contaminated-field setting.
Methods (brief)
The experiment ran from 2017 to 2019 in Taojiang County, Hunan Province, China. Two paddy fields were selected based on soil Cd content: Anlingping Village as the low-Cd field and Xiaopotou Village as the high-Cd field. Three rice cultivars were transplanted into split-split plots with soil-Cd area as the main plot, cultivar as the subplot, and Se treatment as the sub-subplot. Foliar Se was applied as sodium selenite at 50 g/ha Se, split into two sprays of 25 g/ha each. Cd in stems, leaves, spikes, and brown rice was measured after nitric acid/perchloric acid digestion by AA6300C atomic absorption spectrophotometry. Statistical analysis used ANOVA, Student’s t-test, nonparametric tests where assumptions failed, and Spearman correlations.
Implications
Standards work: This is upstream mitigation evidence for rice Cd: foliar Se can lower brown-rice Cd materially, but in this field trial the brown-rice Cd values remained high under contaminated-soil conditions. The study supports supplier-facing agronomic controls rather than finished-product threshold estimates for rice beverages.
Courses: Useful for the soil-to-grain transfer and mitigation module: the same agronomic intervention reduced Cd more effectively in low-Cd fields than in high-Cd fields, showing why mitigation cannot substitute for source-soil screening.
App: Route as brown-rice Cd occurrence and mitigation context for rice ingredients. Do not route as direct plant-milk occurrence evidence; the wishlist target was rice-based plant milk, but the paper measured rice grain and plant tissues.
Microbiome: Not addressed.
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Verification notes
- Fresh auto-fetch ingest 2026-05-19 from the gap-driven rice-based plant-milk Cd wishlist. The actual measured matrix is brown rice in a field trial, so this page routes to rice-bulk-grain as upstream ingredient evidence.
- Numerical ranges are extracted from Tables 2-4 using the brown-rice column only.
- The paper reports Cd only for the HMT&C contamination endpoint; Se is an intervention/nutrient element in this source and has no metal page in the current taxonomy snapshot.
- Methods vendor/equipment names are retained under Part 12 Exception 2.
Update history
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