The aim of modern agriculture is to provide sustainable development which maintains high environmental quality for future generations. One of the main expectations of sustainable development is to reduce the amount of chemicals used in production. The use of byproducts contributes to reducing the amount of applied fertilisers. One of the forms of doing so is the use of byproducts of biogas plants – digestate – which contains the nutrients (e.g. N, Ca, Mg, P, S, K) needed by the produced plants.

The aim of this examination was to determine the impact of digestate on maize grown on N, P, K, Ca and Mg deficient nutrient solution.

Digestate from the biogas plant in Biharnagybajom was used for the analyses. A hydroponics experiment was performed in a growth chamber. Environmental conditions were controlled. Maize (Zea mays L. cv. DKC 5170) was used as experimental plant. We added 50 ml dm-3 fluid by-product to the nutrient solution. At the end of the experiment, the relative chlorophyll content, the quantity of photosynthetic pigments (chlorophyll-a, chlorophyll-b, carotenoids) and the dry weight of shoots and roots were measured.

It was observed that the majority of plants grown on nutrient-deficient nutrient solution supplemented with digestate performed better development and showed more favourable values during physiological analyses than maize grown on nutrient solution without adding digestate.

It can be concluded that digestate from biogas plants had a favourable effect on the nutrient-deficient plants involved in the experiment.

Keywords: biogas plant, digestate, maize, nutrient deficiency