Agronomic solutions to decrease arsenic concentrations

Overview

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Key numbers

The worker extracted the full PDF text with layout preservation twice and compared extraction hashes before commit. The following lines are copied from numeric/table-bearing regions of the PDF and retain the source units and wording where legible:

unique to rice (Ma et al., 2008; Williams et al., 2007a, make up less than 50% of total grain As, though oAs
2007b; Zhao et al., 2010a, 2010b). These molecu- can also exceed 60% of total As (Colina Blanco et al.,
can adsorb As species, limiting uptake into the plant ences. Our team asked questions (Table 1) designed
Arkansas library database and spanned 2008 through across a broad range from 4 to 98% (Jiang et al., 2012;
ual varieties means some Japonica cultivars have 2010; Rahman et al., 2007). Therefore, breeding for
methane (CH4), a potent greenhouse gas emitted dur- 18–74% in comparison to continuous flooding (Kahl-
ment that introduces aerobic periods during the grow- CH4 by 39–83% (Leavitt et al., 2023; Linquist et al.,
can be repeated multiple times throughout the growth the greatest reduction in total grain As, up to 98%
98% in rice when compared to continuous flooding when the water table reaches 15 cm below the soil
Honma et al., 2016a, 2016b; Hu et al., 2013; Islam to lower it by 15–33% in one study (S. Islam et al.,
2021; Xu et al., 2008; Yang et al., 2023). The creation and oAs 5–90% in the grain (Honma et al., 2016;
& Chen, 2017), while others found that it increased loss for studies in this review ranged from 3 to 44%
in the grain, total iAs was still 5–66% lower for rice et al., 2016a, 2016b; Islam et al., 2020; Mukher-
quently occur as CdS, and when the sulfide compo- with AWD causing a 15–32% yield decrease in some
et al., 2016; Hu et al., 2013). Instances in which gation was able to reduce total grain As by 69–98%
2022; Orasen et al., 2019; Seyfferth et al., 2019a, 72% compared to continuous flooding (Honma
grain As by 10–92% depending on the number and
and it can reduce water use by up to 38% (Carrijo uptake in the plant (F.-J. Zhao et al., 2010a, 2010b)
tion reduced total grain As 15–100% (Chou et al., such as Si, Se, Fe, S, and P compounds, and vary in
total grain As by 50% in the one study in this review for rice that improves disease resistance and allevi-
amendments decreased grain total As 7% to an esti- Experiments comparing forms of Si amendment
iAs an estimated 18–62% (Fleck et al., 2013; Li et al., applied as a soil or foliar amendment or used as a
oAs by 33–55% (Seyfferth et al., 2019a, 2019b; Teas- with As for uptake by Si and phosphate transporters
estimated 40–69% (Li et al., 2018; Seyfferth et al., of glutathione and phytochelatins which are part of
husk or straw that promote more reducing conditions, estimated 7–100% (Kaur et al., 2017; Lan et al., 2023;
decrease grain total As to nondetectable levels, a 2016; Lv et al., 2020; Zhou et al., 2017), though two
lick et al., 2018; Zhou et al., 2017). Studies reporting 90% Fe by weight, while the other forms were less
speciation of As in the grain were limited and con- than 60% (Matsumoto et al., 2015). The strength of
Se can be toxic to the plant as well (Reis et al., 2020). the other applied Fe as lodestone (Liu et al., 2020),
tion (0.1%) decreased shoot As concentrations more
Iron than a higher rate (0.5%), suggesting the role of other
total grain As with a range of effectiveness from 13 to that there is a threshold beyond which additional Fe is
92% (Farrow et al., 2015; Ghosh et al., 2022; Honma not beneficial.
25–79% (Fang et al., 2023; Liu et al., 2021; Wisawa-
also react directly with As to form As2S3 under reduc- mated 26–60% (Liu et al., 2021; Zhang et al., 2022)
formation of Fe root plaques that can sequester As amendment raised grain oAs 63%, which was attrib-
amendments lowered total grain As 27–72% in rice, tions with soil biogeochemistry that are not well sim-
tures, typically from 300 to 700 °C, with little or no that the reduction was due to a 15–50% decrease in
As levels by an estimated 18–56% in the rice grain in As accumulation in rice. We suggest that if biochar
decrease As levels in rice because iAs(V) competes bic irrigation methods lowered grain As up to 66%,
rates of application lowered total grain As 14–79% detrimental to the environment (Ayoub, 1999) so high
Yang et al., 2020) or increased grain As 11–33% bic water management practices for maximum effec-

Methods (brief)

(oAs) including dimethylarsinic acid (DMA)
pounds like DMA are carcinogens (IARC, 2012), Compounds containing As occur naturally in the
the Si uptake pathway, which is highly efficient and ated species like DMA, DMMTA, and MMA usually
evidence that DMA and MMA are also taken up by are noted in the analysis below.
sample size suggests that Indica, in general, has a ferent sites and during different years, indicating
the Lsi6 transporter that transports both Si and DMA shown to enhance As sequestration on Fe plaques on
Se can be toxic to the plant as well (Reis et al., 2020). the other applied Fe as lodestone (Liu et al., 2020),
analyses can cost approximately $200 per sample at case, more field-level research should be performed
ularly send samples to test for iAs. Many respondents of yield reductions due to a drier soil environment.
separation of rice sources with differing levels of Abedin, M. J., Feldmann, J., & Meharg, A. A. (2002). Uptake
modulation of antioxidant enzymes and thiols in rice Li, R.-Y., Ago, Y., Liu, W.-J., Mitani, N., Feldmann, J.,
mium (Cd) and dimethylarsinic acid (DMA). Science of 2014.08.004
(2020). Effects of carbide slag, lodestone and biochar Meharg, A. A., Lombi, E., Williams, P. N., Scheckel, K. G.,
on the immobilization, plant uptake and translocation of Feldmann, J., Raab, A., Zhu, Y., & Islam, R. (2008).
system with sulfur application and different water man- Y.-G., Feldmann, J., Raab, A., Zhao, F.-J., Islam, R.,
and micronutrients accumulation in rice grains. Journal F.-J., Stroud, J. L., McGrath, S. P., Feldmann, J., Price,
nology, 44(21), 8108–8113. https://doi.org/10.1021/ C., Raab, A., Feldmann, J., Islam, R. M., & Meharg, A.
Williams, P. N., Raab, A., Feldmann, J., & Meharg, A. A. org/10.1016/j.scitotenv.2020.139869

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

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Verification notes

Identity check: DOI, raw handle, candidate cite-key, and SHA-256 were compared against existing wiki/sources/ pages before creation.
Full-PDF read: pdftotext -layout was run on the full PDF twice; extracted text hashes matched before the page was written.
Numeric verification: numeric/table-bearing lines were selected mechanically from the verified extraction and preserved without unit conversion or rounding.
Brand firewall: the worker skips PDFs when extracted numeric lines appear brand/manufacturer-sensitive; this page contains category-level or species-level evidence only.
HMTc firewall: no threshold, percentile, pass/fail, clean/dirty, or certification math is stated.

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and 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	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised