3. Results
We examined the influence of soil additives in three different qualities (corn silage, hydrochar and pyrochar), two different soil types and three levels of KNO3 fertilizer on the germination success and growth of winter wheat plants.
Seven days after sowing, germination success on soils treated with hydrochar was significantly (p < 0.001) lower (48%) compared to the two other treatments (75% on corn silage and 77% on pyrochar).This difference was still evident at the end of the experiment e until day 31 after sowing, germination rate on soils treated with hydrochar reached 74% and thus was still considerably lower than on soils treated with corn silage (91%) or pyrochar (93%). A comparable negative effect of hydrochar on plant growth could be detected during the first half of the experiment. Nine days after sowing, plants on soils treated with hydrochar only achieved an average height of 4 cm, while plants on corn silage reached 6.6 cm and plants on soils treated with pyrochar 7.5 cm. On days 17 and 21 after sowing, differences in height growth between corn silage and hydrochar treatments disappeared. Thus, height growth of plants on hydrochar significantly surpassed that of the plants on corn silage at the end of the experiment despite a slower growth in the initial phase, but remained below that of plants grown on hydrochar (Table 2).