Biodiversity and Biomass Production of Weeds in a Long-Term Fertilization Experiment

A field experiment was carried out to study the influence of nitrogen (N), phosphorus (P), and potassium (K) nutrient supply on weed flora in maize. The investigations were conducted in a long-term fertilization experiment launched in 2003 on a loamy chernozem soil with lime deposits, in Fejér County, Hungary. The composition, biomass weight, and density of weeds were determined in relation to different nutrient supplies. Seventy-five percent of weeds consisted of three species: Ambrosia artemisiifolia L., Datura stramonium L., and Helianthus annuus L. Density of weeds varied relative to the different nutrient treatments, with a range of 82–131 plants m ⁻². The total weed density was significantly lower by 19.9–37.8 percent in the N-containing treatments (NP, NPK) than in non-N treatments. The density of the nitrophil D. stramonium L., Chenopodium album L., Chenopodium hybridum L., and Amaranthus blitoides S. Watson was higher when N supply was greater.