Samsidar et al. 2023 - Ultisol soil metals across palm, rubber, forest, and vegetable land uses

Samsidar and colleagues used X-ray fluorescence and laboratory soil tests to measure metal and nutrient elements in Ultisol soils from palm, rubber, forest, and vegetable land-use areas in Muara Jambi Regency, Indonesia. This is in-scope a3 soil-pathway and source-attribution context for plantation and vegetable production landscapes, not palm-oil product occurrence.

Key numbers

Sampling covered four locations and two depths: T1 and S1 from a palm plantation, T2 and S2 from a mixed palm/rubber/forest location, T3 and S3 from natural forest, and T4 and S4 from a vegetable plantation. T samples were 0-20 cm and S samples were reported as 20-50 cm in the methods; the table note prints 20-40 cm and contains a typo for the final sub-sample label.

Table 1 reports metal elements as percent. Decimal commas below are preserved as printed by the source:

The paper also reports pH values of 3,71 (T1), 3,61 (S1), 3,78 (T2), 3,65 (S2), 3,71 (T3), 3,68 (S3), 5,58 (T4), and 5,50 (S4). The authors state that locations 1 and 2 had higher Al content than locations 3 and 4 and lower Mg content.

Linear-regression modeling found R2 = 0.938 for pH against metal elements, R2 = 0.934 for pH against macronutrients, and R2 = 0.767 for pH against micronutrients. The authors conclude that pH had the strongest correlation with metal elements among the three modeled groups.

Methods (brief)

Soil samples were collected from Jambi Luar Kota in Muara Jambi district: a palm plantation, a mixed palm/rubber/forest location, natural forest, and a vegetable plantation. A 10 m x 20 m plot was used at each location; five top-layer and five sub-layer samples were taken and mixed per location-depth. Samples were air dried, ground, sieved through a 15 mesh/< 2 mm sieve, and analyzed by X-ray fluorescence using an S2 PUMA Series 2 instrument. Laboratory tests measured pH (H2O, 1:2), total nitrogen by Kjeldahl, organic carbon by Walkley and Black, and available phosphorus by Kurt Bray 1.

Implications

Certification: Do not use these values as palm-oil, vegetable, rubber, or forest-product occurrence. They are soil metal and fertility-context values.

Courses: Useful source-attribution and supply-chain context for explaining how plantation land use and soil chemistry can change the metal reservoir available to crops.

App: Context only. The source can inform upstream soil-risk narratives for Jambi plantation landscapes, not finished-product scoring.

Wiki pages this source may touch

• soil-to-plant-transfer
• source-attribution-environmental-burden-apportionment
• aluminum
• nickel
• chromium
• manganese
• zinc
• iron
• titanium
• vanadium

Verification notes

Recovered from skip:not-food-occurrence under the 2026-06-10 inclusion-by-default rule. The old skip treated the paper as out of scope because it measured soil fertility and soil metals rather than palm-oil occurrence. On reading, it is in-scope a3 soil-pathway and source-attribution context for palm, mixed plantation, forest, and vegetable land-use soils.

Numbers were checked against the abstract, sampling methods, Table 1, regression prose, and conclusion in the extracted PDF. The source does not report As, Cd, Pb, food, crop, or finished-product concentrations. Products and ingredients are intentionally empty. agricultural-soil, plantation-soil, and ultisol are descriptive matrix terms for this soil-only pathway page.

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.