Interactive effects of soil acidity and fluoride on soil solution aluminium chemistry and barley ( Hordeum vulgare L.) root growth

• Published in: Environmental pollution (1987) 2007-02, Vol.145 (3), p.778-786
• Main Authors: Manoharan, V., Loganathan, P., Tillman, R.W., Parfitt, R.L.
• Format: Article
• Language: English
• Subjects: Aluminium toxicity; Aluminium–fluoride complexes; aluminum; Aluminum - analysis; Aluminum - toxicity; Aluminum Compounds - analysis; Animal, plant and microbial ecology; Applied ecology; barley; Barley root growth; Biological and medical sciences; Calcium - deficiency; Ecotoxicology, biological effects of pollution; fertilizer application; Fertilizers - toxicity; fluorides; Fluorides - analysis; Fluorides - pharmacology; Fluorides - toxicity; Fundamental and applied biological sciences. Psychology; General aspects; greenhouse experimentation; Hordeum - drug effects; Hordeum - growth & development; Hordeum vulgare; Hydrogen-Ion Concentration; Phosphate fertiliser; Phosphorus - toxicity; phosphorus fertilizers; phytotoxicity; Plant Roots - drug effects; Plant Roots - growth & development; provenance; regression analysis; root growth; Soil - analysis; Soil acidity; soil pH; Soil Pollutants - analysis; Soil Pollutants - pharmacology; Soil Pollutants - toxicity; soil pollution; soil solution; soil-plant interactions
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2006.05.015

A greenhouse study was conducted to determine if concentrations of fluoride (F), which would be added to acid soils via P fertilisers, were detrimental to barley root growth. Increasing rates of F additions to soil significantly increased the soil solution concentrations of aluminium (Al) and F irrespective of the initial adjusted soil pH, which ranged from 4.25 to 5.48. High rates of F addition severely restricted root growth; the effect was more pronounced in the strongly acidic soil. Speciation calculations demonstrated that increasing rates of F additions substantially increased the concentrations of Al–F complexes in the soil. Stepwise regression analysis showed that it was the combination of the activities of AlF 2 1+ and AlF 2+ complexes that primarily controlled barley root growth. The results suggested that continuous input of F to soils, and increased soil acidification, may become an F risk issue in the future. Addition of high rates of fluoride to strongly acidic soils can reduce barley root growth due to the toxicity of aluminium–fluoride complexes formed in soil solution.