Summer truffle (Tuber aestivum), also known as Burgundy truffle, is getting interest in Poland in terms of cultivation as a promising incentive for rural areas. Yet the occurrence of the fungus in wider scale in our country has been confirmed in the last decade. Ecological factors that determine the occurrence of T. aestivum are rather well known in the Mediterranean region, whereas such knowledge is limited in northern Europe. The aim of this work was to find the correlations between essential nutrients in surface horizons of soils typical of truffle occurrence. The study area is situated in the Nida Basin in southern Poland. Principal component analysis (PCA) showed that active carbonate content is the variable that accounts for the greatest percentage of occupancy in the T. aestivum habitat. In this paper we propose that active carbonate is a major factor in the fruiting of summer truffle. The obtained results could have applications in natural harvesting and truffle culture.