The purpose of this paper was to study the usability of new ammonium absorber material as fertilizer. The vermiculite-material which effectively binds ammonium nitrogen to its structure has been developed to remove ammonium ions from waste waters. The material is further developed for fertilizer use. At first step the absorption material was processed with the reject water of biogas plant. Then it was utilized as the nutrient source of garden plants. Chinese cabbages were used as test plants in the work. Significant increase of the growth of the Chinese cabbage was observed when comparing to those cultivations where plants have got normal nitrogen fertilization.