*4.1. Physicochemical and Chemical Properties of Soil*

The abundance of available phosphorus and potassium in the soil, as well as the highest sorption capacity and soil saturation with base cations, were probably the main factors which affected the yields of the tested plants (Figure 8). Grain yield produced from 1 m2 of the plot sown with winter wheat reached 0.462 kg grains, that achieved from the plot sown with winter rape reached 0.350 kg grains, and that for field pea reached only 0.130 kg grains. Next to the natural plant features, the physicochemical properties of the soil are closely related to the development of the root system. Besides the varied chemical composition of the plant species grown in the study, the size of the root system was probably the main determinant of the differences observed in the microbiological and biochemical properties of soil, because plant species and soil fertility are the key indicators of the biological activities of soil [64]. The superiority of one factor over another is affected by multiple habitat factors, like, e.g., soil tillage system [65] the contents of phosphorus and Ca2<sup>+</sup>, Mg2+, Al3<sup>+</sup> cations, and the pH value of soil [66].
