A 2-year field study was conducted to evaluate effects of nitrogen (0, 12.5, 25 kg/da N) rates and previous crops on 2 hybrid corn cv Maverik and Bora varieties planted as second crop following either chickpea or wheat during 2004 and 2005. Split-split plot experimental design was used with 4 replications. Tasseling period, ear silk period, first ear height, plant height, stem diameter, ear length, 1000 seed weight, seed weight of each ear and seed yield parameters were evaluated. Results indicated that effects of previous crops for ear silk period, 1000 seed weight, seed weight of each ear and seed yield of corn varieties were highly significant during both years, while first ear height and ear length were significantly different during 2004, only. The N rates significantly affected tasseling period, ear silk period, first ear height, plant height and seed yield during both years. Effect of N rates was also significant for stem diameter and ear length during 2004 while 1000 seed weight was significant during 2005, only. There were significant differences between 2 corn varieties for tasseling period, ear silk period, first ear height, ear length, seed weight of each ear during both years whereas 1000 seed weight and seed yield showed significant differences during 2004 and stem diameter showed a significant difference during 2005, only. There was a previous crop x N rate interaction for seed yield during both years while significant previous crop x N rate interactions were determined for 1000 seed weight and seed weight of each ear in 2005. This study suggested that N rates and corn cultivars might result significant differences on tasseling period, ear silk period, first ear height, ear length and seed weight of each ear. The results also indicated that species of previous crops significantly affect corn seed yield and yield parameters and winter legumes such as chickpea might help to maximize corn yield in a crop rotation system.
