Effects of Nutrient Supply and Soil Tillage on the Weeds in Maize

The soil tillage study was carried out in Keszthely in 2006-2008. The study included different cultivation methods: no-till drill, disk tillage, conventional tillage (plowing), and five nitrogen (N) fertilizer rates. The bifactorial trial was arranged in a split-plot design with four replications. Crop rotation: winter wheat-winter wheat-maize-maize. Weeds were not killed before the investigation. The weed survey was made with Balazs-Ujvarosi coenological method on the first days of June. We collected all plants of every weed species by plot. The sample area was 1 m(2). Five maize plants per plot were sampled. Maize was at the 3-4 leaf stage. Aerial parts of plants were collected and the fresh- and dry-matter weights were measured. The biomass production of each weed species was compared with maize to determine if weeds have an effect on maize during this early period of maize growth. Plow cultivation markedly reduced weed cover, the number of perennial and annual weeds in the weed flora and the number of occurring weed species. The most dominant weeds were Chenopodium album, Amaranthus retroflexus, and Cirsium arvense with 60% of the total weed cover. Seven of the 12 dominant weed species are annual weeds. The dry-matter weight of maize was reduced with less tillage. In this sample period the different N doses had no effect to the dry-matter weight of weeds. The N fertilizer increased the dry-matter weight of maize compared to no N fertilizer.