The dynamics of mobile iron compounds and redox potential of Albic Pantostagnic Luvisol depending on long-term various fertilisation

Iron is one of the most important trace elements in plant nutrition. The content of ferric iron and ferrous oxide in the soil and their dynamics during the vegetation period can be used to assess not only the course of oxidation-reduction processes but also the supply of plants with this available trace element. Therefore, the main objective of the research was to find out the effect of long-term fertilisation and liming on the dynamics of the redox potential and mobile iron compounds in the Albic Pantostagnic Luvisol of the forest-steppe of Western Ukraine. The research was conducted under the conditions of a long-term experiment established in 1965 with different doses of mineral fertilisers, manure, and lime on the Albic Pantostagnic Luvisol. It was found that the gross content of iron compounds and the content of their mobile forms in the Albic Pantostagnic Luvisol are within the optimal range for the plant's growth and development. Only in the case of long-term use of this soil without fertilisation or in the conditions of long-term mineral fertilisation, which contributes to the increase of the acidity of the soil solution and to the creation of restoring conditions during the periods of overwetting, iron can turn into a toxic substance.