n the cultivation of crops in recent times, in addition to taking care of the balanced supply of nutrients to plants and the protection of soil resources, it is also important to take into account the non-productive factor by implementing production systems based on balanced fertilisation. The aim of this study was to demonstrate the effect of soil kind and the application of a new fertiliser based on a urea and ammonium nitrate solution with potassium thiosulphate (UAN-KTS) on the yielding and biometric characteristics of spring wheat, spring rape, and maize to determine the optimal N:K:S ratio. An increase in the soil kind increased the weight of 1000 spring rape seeds, the yield of maize fresh matter, a reduction in the height of spring wheat and maize plants, a reduction in the yield of spring wheat grains and straw, and the yield of the fresh and dry matter of spring rape straw. A higher nitrogen dose promoted the growth of spring rape at the later growing stage and maize and had a positive effect on the yield of spring wheat grains and straw, spring rape seeds and straw, and the above-ground parts of maize. The application of potassium fertilisers caused a significant increase in the spring rape plant height, an increase in the yield of spring wheat grains and straw and spring rape seeds and straw, the above-ground parts of maize, a reduction in the plant height at the beginning of the spring wheat growing period, and a reduction in the weight of 1000 spring rape seeds (only on the soil with rich quality). The fertiliser with the N:K2:S2 ratio had a particularly favourable effect on the yielding of spring wheat. In the cultivation of maize, the same effect was most often obtained under the influence of fertiliser in the ratio of N:K1:S1 on the weaker soil fertilised at the same time as a higher dose of nitrogen (N 1) and N:K2:S2 (in other cases). In the case of spring rape, generally, fertiliser with N:K1:S1 was the strongest, although, in some objects, a higher yield was achieved under the influence of N:K2:S2. The existence of statistically confirmed correlations (expressed as the percentage of the variability observed) between the soil kind and the fertilisers applied and the yielding and biometric characteristics of the plants were observed.