EN
The paper presents the results of some important investigations carried out in Poland, which aimed to determine the effectiveness of applying organic fertilizers under maize crop. Special attention was paid to slurry since more experiments concerned that kind of fertilization. They intended to determine the fertilization activity of nitrogen contained in the slurry. It was found that the maize crop responded very favourably to both, cattle and pig slurry. It was also concluded that the slurry may be applied under maize crop at the rates covering nutritive N requirements of the plants partly or in total.