Year: 2026 | Month: June | Volume 19 | Issue 2
Managing Heavy Metal Bioavailability in French Bean (Phaseolus vulgaris L.) Production Systems Using Soil Amendments: Mechanisms, Evidence, and Food Safety Implications
Erick Osoro Mogire1
3*
Joseph Miriti2
Emmanuel R Mwakidoshi1
Lydiah LM Kitonga4
Douglas N Nyang’au5 and Joseph Gweyi-Onyango1
DOI:10.30954/0974-1712.02.2026.1
Abstract:
Heavy metal contamination of agricultural soils poses a growing threat to safe and sustainable food production, particularly in intensive horticultural systems. French bean (Phaseolus vulgaris L.), an economically important legume widely consumed locally and traded in export markets, is highly susceptible to the uptake and accumulation of toxic metals such as cadmium (Cd), lead (Pb), and copper (Cu). This raises serious concerns regarding crop productivity, food safety, and public health. This review synthesizes current knowledge on the sources, behavior, and management of heavy metal bioavailability in French bean production systems, with particular emphasis on the role of soil amendments. Major contamination pathways examined include synthetic agro-inputs, irrigation water, organic amendments, atmospheric deposition, and geogenic sources. The review further evaluates the biological and physicochemical mechanisms governing metal mobility and plant uptake, highlighting the influence of soil pH, cation exchange capacity, microbial activity, and organic matter content. Particular attention is given to the roles of organic and inorganic soil amendments in reducing heavy metal bioavailability through adsorption, complexation, precipitation, and ion competition. Evidence from experimental and field studies shows that amendments such as lime, phosphatic materials, compost, and biochar can substantially reduce metal bioavailability while improving soil quality and crop performance. Integrated amendment strategies frequently demonstrate synergistic effects and outperform single-input applications, although their effectiveness remains dependent on soil type, amendment properties, and metal speciation. Despite increasing research interest, studies specifically focused on French bean systems remain limited, particularly regarding dose optimization, varietal responses, and long-term field validation. Addressing these gaps is essential for developing evidence-based management strategies that protect soil health, crop quality, and consumer safety.
© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Highlights
- Heavy metal contamination threatens French bean productivity, food safety, and consumer health.
- Soil pH, organic matter, CEC, and metal speciation regulate metal mobility and plant uptake.
- Organic and inorganic amendments immobilize metals through complementary physicochemical and biological mechanisms.
- Integrated amendment strategies can reduce metal uptake while improving soil quality and crop performance.
- Research priorities include amendment-rate optimization, varietal responses, and long-term field validation.
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