Iodine is an essential trace element for animals. The major sources of iodine for animals are contained in feed and water, in which the iodine content depends on its amount in the given environment. The aim of this study was to analyse and evaluate the iodine content in soil, soil water, grass mass and also to assess the effect of grassland exploitation on the iodine content in the Šumava and Jeseníky Protected Landscape Areas (PLAs) in the Czech Republic. The soil type in both PLAs was Modal Cambisol. Soil samples were collected from two different depths (up to 15 cm, 16-30 cm). Soil water samples were extracted from a depth of 40 cm and grass mass samples were collected from an area of 1 x 1 m. The areas according to exploitation intensity were as follows: EA1 – a meadow mowed twice a year, EA2 – a meadow mowed once a year, EA3 – a meadow was not mowed for 5 years. Iodine in soil and grass mass was determined by a spectrometric method (the Sandell–Kolthoff reaction). Iodine in water was measured by the ICP-MS method. The average iodine content in the Jeseníky PLA was 0.91±0.18 mg kg−1 in soil, 1.16±0.79 μg dm-3 in soil water and 0.16±0.07 mg kg−1 of 100% dry matter of grass and in the Šumava PLA was 4.69±0.70 mg kg−1 in soil, 3.12±0.91 μg dm-3 in soil water and 0.31±0.13 mg kg−1 of 100% dry matter of grass. A significantly (p

25.3.2020