Effect of Nitrogen Rate and Corn Density on Weed Management under Stale Seedbed System

Field experiment was conducted to study the effect of nitrogen and plant density on weed population in corn under stale seedbed planting system. This study was done in the farm of Agriculture College of Tehran University in 2010. The experiment was done in complete block design with three replications. Main plot consisted of stale seedbed and conventional seedbed preparation. Subplots consisted of four levels of nitrogen fertilizer (0، 270، 325 and 380 kg ha-1) × 3 corn densities (7، 8 and 9 plants m-2). Results showed conventional seedbed had the highest biomass of weeds at 7 plants m-2 and 325 kg N ha-1. At this treatment، stale seedbed could decrease the weed biomass by more than 96. 6%. In general، stale seedbed resulted in higher values of corn growth characteristics i. e. plant biomass، height، leaf area index. Using stale seedbed، the treatment of 380 N kg ha-1 + 9 corn plants m-2 had the highest corn biomass and grain yield. In general، stale seedbed system in corn production can be as a useful tool to better manage the weeds، improve corn growth.