Plants experience a number of stresses in the environment, including those caused by salts, drought, heavy metals and frost. To maintain safety during winter, deicing salt (sodium chloride) is sprinkled over roads. In global practice, natural and laboratory investigations of the impact of road maintenance salts on various species of plants are carried out. So far in Lithuania, only single cases of such investigations have occurred. The aim of this investigation is to determine which of the analysed herbaceous vegetation species (perennial ryegrass, fescue grass, meadow-grass) shows the highest degree of resistance to toxic impact of salts (stress), to set the toxic limits of salt concentrations and to analyse how salts impact on the core parameters of herbaceous vegetation. The investigation proves that NaCl content in the soil negatively affects the growing process of grass vegetation, i e it slows down increase of its above-ground part and reduces its phytomass. During experiments it was determined that perennial ryegrass had the highest degree of resistance to toxic impact of salts.

To maintain safety during winter, deicing salt (sodium chloride) is sprinkled over roads. Snow, mixed with highway salt, is then cleared by snowplows and usually ends up on roadsides where trees are planted. On conifers, adversely affected by deicing salt, needle shedding is accelerated. Undesirable results for the environment, caused by road maintenance chemical, are damaged vegetation, soil, polluted surface and groundwater, therefore, fauna, and people are also negatively impacted. The aim of modelling is to find a coefficient for calculating ryegrass, fescue grass and meadow‐grass length of overground part after some time, accepting that the concentration of salt in melting snow and air temperature will be the same during investgation.