Study of Nitrogen Use Efficiency and Growth Analysis of Corn, Affected by Plant Density and Nitrogen Fertilizer Levels

To investigate the effect of various levels of nitrogen fertilizer and different plant density on nitrogen use efficiency (NUE) and growth analysis of corn, a split plot experiment based on randomized complete blocks design with three replications was conducted in Ardabil Agriculture Research Station in 2005. The factors were nitrogen fertilizer at three levels in main plots (0, 75 and 150 Kg N ha-1) and plant densities in subplots (7, 9 and 11 plants m-2). The results showed that NUE was significantly affected by plant density and nitrogen levels. Maximum rate of NUE was obtained in application of 75Kg N ha-1. There was no significant difference between 75 and 150Kg N ha-1. With increasing plant density, the NUE was decreased, and maximum NUE was also obtained in density of 7 plants m-2. With increasing plant density and nitrogen levels, total dry matter, crop growth rate and grain yield were increased. Grain yield per plant decreased with increasing plant density. With increasing nitrogen levels and decreasing plant density the number of kernel per row, and number of kernel in ear were increased. Numbers of kernel in ear were only affected by nitrogen levels, and was decreased with increasing nitrogen levels. Number of ear per plant and weight of thousand grains wasn’t affected by levels of the experimental factors.