Effects of Crop Management Systems On Weed Abundance and Soil Seed Bank

Given the importance of different weed management systems (MS) for weed communities and soil seed bank, our aim was to study the impacts of organic (Org) and conventional (Conv) MS in tomato and sugar beet on the abundance of weeds and weed seed bank. The results have shown that in both crops the aboveground weed flora is dominated by 2–3 species in the Conv MS, while it is more diverse in the Org MS. In both crops the soil seed bank is less diverse when compared with the aboveground weed flora. Furthermore, a comparative analysis of the weed flora and soil seed bank has shown a high number of different weed seeds in the soil for tomato, unlike sugar beet, where a higher number of weeds was determined in the aboveground weed flora. In tomato, the soil seed bank is more diverse in Org MS (4.1± 1.5) than in Conv MS (3.8± 1.3), which was also true for the aboveground plant biodiversity (4.6± 1.1 vs. 3.6± 1.5 species, respectively). Also, although the differences in aboveground weed density and abundance in tomato were not statistically significant, seed bank reserves in the Org MS were significantly more abundant (40.4± 16.7 weed seeds vs. 4.5± 3.6 in Conv MS). This study has also shown that in sugar beet there were practically no differences between Org and Conv MS, even though the abundance of its aboveground weed flora was higher in Org MS (70.2± 29.4 vs. 38.1± 21.2 plants/m2 in Conv MS). In conclusion, it can be said that although both MS had similar effects on weed management in tomato, for sugar beet Org MS has proven to be less effective in weed control.