Biochar and Fertilization Effects on Weed Incidence in Winter Wheat

Biochar, a carbon-rich material, is highlighted to improve soil fertility, simultaneously mitigating climate change by carbon sequestration. Combined with mineral fertilizer, it can increase weediness, the major source of yield loss in agricultural production. Research with biochar was conducted in Eastern Croatia in 2016, with the aim to investigate the influence of biochar and mineral fertilizer on weed infestation and winter wheat yield. Field experiments were set up as a split-plot where biochar (B) was the main factor and fertilization was the sub factor. The main treatments were: B0 (control without biochar), B1-5 t ha−1, B2-10 t ha−1 and B3-15 t ha−1. Fertilization sublevels were F0) without fertilizer and F1) optimal dose of fertilizer. Weediness was determined by counting and measuring aboveground biomass. The treatments with the greatest effect on weediness were B3 and F1 in the winter wheat tillering stage. In the winter wheat ripening stage, treatment B3 obtained the highest weediness and F1 significantly reduced weed density. Biochar treatment B3 increased winter wheat yield by 77% in relation to the control. The application of biochar combined with fertilization affected the level of weediness depending on agroecological conditions, but with a significant increase in yield.