Soil additives cut toxic metals in peanuts near mine sites
Gaothobogwe K, Manyiwa T, Oleszek IS, Rzeznicka II, Ultra V
Phytoremediation
If you garden on land with a history of industrial use or near old mining or smelting sites, this shows that cheap, widely available soil amendments like compost and ash byproducts can measurably lower the heavy metals your crops pull up from the ground.
Farms near a copper-nickel mine in Botswana had peanuts loaded with toxic metals from contaminated soil. Researchers tried mixing in fly ash, compost, and lignite (a type of soft coal) either alone or together, and found the combo worked best, cutting toxic metal levels in the peanut kernels by more than 30%. The treatments also helped the soil and boosted how much peanut crop the plants produced, though for a few of the worst contaminants, risk levels stayed high enough to still be a health concern.
Key Findings
Combining fly ash, compost, and lignite reduced toxic element accumulation in peanut kernels by more than 30% compared to untreated control soil
All four amendment treatments raised soil pH and lowered both total and plant-available concentrations of toxic elements across three farms at varying distances from the mine
Estimated dietary exposure risk scores (hazard quotient and hazard index) dropped significantly after treatment but still exceeded the safety threshold of 1 for some toxic elements in children and adults
chevron_right Technical Summary
Mixing fly ash, compost, and lignite into contaminated soil near a copper-nickel mine in Botswana cut toxic metal levels in peanuts by over 30%, though some health risks remained above safe limits even after treatment.
Abstract Preview
Original paper
Soil amendments reduced potentially toxic elements (PTEs) in peanuts (Arachis hypogaea L.) grown in farmlands near Cu-Ni mine in Central Botswana.
This study evaluated the effects of fly ash (FA), compost (COMP), lignite (LIG), and their combination (FA+COMP+LIG) on soil chemical properties, PTE total and available concentrations, PTE uptake ...
open_in_new Read full abstractAbstract copyright held by the original publisher.
Species Mentioned
Was this useful?
Want to tell us more? (optional)
Thanks for the note!
Something went wrong — please try again.
Too many submissions. Try again in an hour.
Targeted knockout of a host peroxisomal peptidase confers field resistance to...
The corn in your grocery store and the staple food keeping millions of East African families fed is under serious threat from a viral disease that can wipe o...
The peanut, also known as the groundnut, goober, goober pea, pindar or monkey nut (UK), is a legume crop grown mainly for its edible seeds, contained in underground pods. It is widely grown in the tropics and subtropics by small and large commercial producers, both as a grain legume and as an oil...