Evaluation of relation between weed population and nitrogen use efficiency in wheat as affected by integrated fertilizer management

In order to evaluation of relation between weed dynamic and utilization of nitrogen in weed as influence of integrated fertilizer management in different weed densities، a field experiment was carried out in experimental farm of Agricultural Faculty of Shahid Chamran university of ahvaz at 2011-2012 growing season. Experimental design was based on a split-plot with three replications. Main plot was 5 integrated fertilizer managements and sub plot was 3 weed densities. Our results showed that the treatment 75% chemical fertilizer whit Biological fertilizer in lower weed density had the highest weed density and dry weight. Narrow leaf and broad leaf weeds was dominant species in 100% chemical fertilizer and 100% biological fertilizer Treatments، respective. Also، weed diversely was reduced by reduction. So، Treatment 100% biological fertilizer had the highest weed density nitrogen fertilizer utilization efficiency was increased by reduction of nitrogen chemical fertilizer. In addition، all nitrogen useefficiency. Indices were more affected by nitrogen chemical fertilizer، than weed density. Based on our results،increasing dependence to biological fertilizer، will reduce is the compatibility of wheat plant، in early growth period، which caused increasing in density and decreasing of weed at the wheat growth period.