The aim of the study was to revise the limit values for the assessment of the microelement concentration in the soil determined with 1 M HCl. Unlike the values used so far to determine low, medium and high concentrations, the new values indicate only the low concentration limit below which fertilisation is necessary. Moreover, the new values are differentiated according to the plant species, which is related to the different sensitivity of the plants to microelement deficit. These values were prepared for wheat and rapeseed on the basis of a large data collection of 3865 pairs of soil-plant samples taken from production fields located in 16 voivodeships of Poland. The concentration of micronutrients was determined in all soil and plant samples. In addition, pH, texture, and the content of organic carbon and available phosphorus were determined in soil samples. Moreover, grain and seed yield after wheat and rapeseed harvest was estimated for all fields. Two independent calculation methods were applied in order to increase the reliability of the developed values. One of them was the method of regression equations, using the micronutrient bioaccumulation coefficient, its critical concentration in the plant and relevant soil features. The equations were constructed using the Stagraphics program. For each micronutrient, 8 models were tested in search for the equation with the highest determination coefficient r2. To verify the values calculated in this way, the "High Yield Method" was used, which involved determining the smallest concentration of a micronutrient in the soil at which a high yield could be achieved.