Fertiliser application is one of the most important operations in agricultural production. It helps to increase the quality and quantity of the crop. However, the addition of too many ingredients or an unbalanced nutrient profile has a negative effect on crops. It is therefore important to apply fertiliser rationally and to achieve the correct level and uniformity of fertiliser distribution. The aim of this study was to develop a new model for lateral distribution uniformity during fertilisation. The tests were carried out under field conditions in a winter wheat crop. The quality of operation of three two-disc fertiliser spreaders at a travel speed of 1.22 ms-1 was investigated. A Lagrange interpolation model was used to analyse the data. The accuracy of models was very high (R2 > 0.985). Themodels developed can be used in practice to facilitate control of the spreader operation, which will help to ensure uniform fertiliser distribution..