The rhizosphere of plants is a very dynamic system that can vary over time depending on the plant physiological state, its developmental stage and environmental conditions. The concentrations of many elements in the rhizosphere soil are also not constant. Until now, more attention has been paid to long-term (seasonal and annual) changes in the root zone. However, short-term (within hours) fluctuations in the concentrations of elements in the rhizosphere soil of different plant species have not been studied enough. In this work, diurnal variations in the concentrations of macro- and trace elements in the rhizosphere of two widespread plant species, couch grass and nettle, growing in the same place under the same conditions, were studied. The short-term variations in the rhizosphere soil of couch grass and nettle were significant and regular. Depending on the time of sampling, the temporal changes of one or another element in the soil taken from roots of the plants were often different. This may be caused by differences between couch grass (monocot) and nettle (dicot), which release various organic compounds into the rhizosphere, and may also be due to natural factors, including climatic conditions.