The application of flue gas desulphurisation (FGD) gypsum as an acid soil ameliorant was studied in order
to establish the possible detrimental effects on plants and animals feeding on them caused by the high
fluoride content in this by-product. A greenhouse experiment was conducted under controlled conditions
to determine the F accumulation by two plant species (alfalfa (Medicago sativa L.) and ryegrass (Lolium
perenne L.)) grown in acid soils amended with different FGD gypsum doses (0–10%). The F concentrations
in plant aerial parts were comprised in the range 22–65 mg kg−1, and those in plant roots varied from
49 to 135 mg kg−1. The F contents in the above-ground plant tissues showed to decrease with the FGD
gypsum application rate, whereas an inverse trend was manifested by plant roots. The increase in the
soil content of soluble Ca as a result of the FGD gypsum addition seemed to play an important role in
limiting the translocation of F to plant aerial parts.