The aim of this study is to examine the effect of spraying two commercially available MCPA (4-chloro-2-methylphenoxyacetic acid) formulations as a salt (Chwastox Extra 300 SL), as an ester (Chwastox AS 600 EC), and as two herbicidal ionic liquid (HIL) forms of MCPA – namely Ethoquad O-12 (ETQ-O12) and didecyldimethylammonium (DDA, a cation), and MCPA (an anion) – on the uptake of Ca, Mg, and Fe by spring barley (Hordeum vulgare L.). The total elemental contents of the aboveground parts of the spring barley were measured using FAAS (Varian AA240FS) 24 h and 72 h after fields were sprayed and compared with untreated plants. The field studies revealed lower contents of Ca, Mg, and Fe in the material after use of the commercial formulation compared to HILs. The greatest reduction in the uptake of macroelements was observed after using MCPA as a salt; the reduction amounted to 28% for Fe and 14% Mg, while for Ca it was 10%, but for Mg the differences between treatments were not significant in any case. The greatest drops in the uptake of the reference macroelements were observed for Chwastox 300 SL<Chwastox AS 600 EC<[ETQ-O12][MCPA]<[DDA][MCPA] in comparison to the control sample.