The effect of tillage systems on soil seedbank

The research was carried out in 2006–2008 in a static field experiment started in 1993 in the Research Field Station at Lipnik near Stargard Szczeciński, on Eutric Cambisol soil. In soil samples taken from following layers: 0–10, 10–20, 20–30 cm of soil under ploughing, ploughless or direct drilling tillage systems, species composition and number of weed diaspores were evaluated. In the samples, in total there were diaspores of 17 weed species. Chenopodium album was the dominant weed species in all soil layers and tillage systems. The number of diaspores was significantly dependent on tillage system and soil layer. Irrespective of soil depth, the highest total number of diaspores (12251 pcs × m-2) was in the treatment with the ploughing tillage system, while for the other treatments this number was significantly lower: by 14% for ploughless tillage and by 51% for the direct drilling treatment. Regardless of soil tillage system, the highest total number of diaspores (19936 pcs × m-2) was in the top layer, while in the next layers this number was significantly lower (by 62 and 87%, respectively). The largest number of weed diaspores was in the top layer of soil after long application of the ploughless tillage system.