The objective of the project was the determination of the degree of mineral nitrogen compounds (N-NO3, N-NH4) contamination of soil at various farm objects on a swine farm. The research was carried out on two swine farms in the south-east of Poland, situated on black-earth (chernozem) soil. The analysed material was soil samples gathered from the surroundings of various farm objects: a manure site, a fattening house, a swine yard and a dunghill. The samples were taken from six layers, situated at every twenty centimetres down to the depth of 100 cm, and the last layer was 100-150 cm deep. The determination of the content of ammonium nitrogen in the soil samples was done colorimetrically using the Nessler method, and the content of nitrate - nitrogen using the modified brucine method. In the analysed soil samples the dominant form of nitrogen (with the exception of the dunghill on farm B) was nitrate nitrogen – both in the surface layers and in the deeper layers of the soil profile. The highest medium content of nitrate nitrogen was observed in the soil at the distance of 10 m from the dunghill (111.52 mg N kg-1). The content of nitrate nitrogen was substantially influenced by the farm object at which the soil samples were gathered, the soil layer, and the interaction between these both factors. Ammonia nitrogen showed a tendency to accumulate in deeper layers of the soil profile. In the case of the dunghill, the concentration of the analysed component increased gradually, until it reached the amount of 109.68 mg kg-1 at the depth of 100-150 cm. The content of ammonia nitrogen in the soil on the grounds of the analysed farms was substantially determined (P<0.01) by the object, the depth of the soil profile, and the interaction between the two factors.