Title: Effect of planting density, rate and time application of N fertilizer on rice yield of 203 and 206 lines
Author: Mohammad Taghi Karbalaei Aghamolki
Abstract: The population increase and the increasing need of humans for food on the one hand, and the limitation of resources on the other, indicates that the only way to achieve greater production is to increase yield per unit area, through the production and use of new and high yielding rice cultivars is possible with the application of very suitable methods. In order to achieve the best planting distance and the amount and application time of N fertilizer per unit area for two lines 203 and 206, a factorial in a randomized complete block design was conducted in the Rice Research Institute of Iran-Mazandaran province in 2013. Rice lines factors were 203 and 206, Planting spacing factor was 20 × 20 and 25 × 25 cm, nitrogen levels at 46, 92 and 138 kg N ha -1 and nitrogen consumption time at two levels (1) before planting 60% nitrogen at base + 40 % for 20 days after transplantation 2- before planting 60% nitrogen at base + 20% for 25 days after transplantation + 20% for 45 days after transplantation) with three replications. The effect of cultivar type on plant height, number of grain per panicle, and days to maturity at 1% probability level and for grain yield at 5% probability level was statistically significant. The effect of nitrogen treatments on the number of days to maturity at 5% probability level and the effect of nitrogen fertilizer consumption on the number of tillers and number of grain per panicle at 5% probability level and the effect of planting spacing treatment on plant height and the number of days to maturity at a 5% probability level and for the number of tillers at a 1% probability level has shown a significant difference. The results showed that line 203 at nitrogen level N92 with grain yield (5807 kg ha-1), twice nitrogen splitting (5727 kg ha-1) with 20 × 20 planting spacing with grain yield (5752 kg ha-1), had the highest grain yield, and Line 206 at nitrogen level N138 with 6276 kg ha-1 grain yield, with 6173 kg ha-1 split three times and with planting spacing of 20 × 20 with 6260 kg ha-1, showed the highest grain yields. According to the results, the planting spacing is recommended for both lines of 20 * 20 for achieving more yield per unit area. Line 206 yield with 138 kg nitrogen fertilizer per hectare (6276 kg ha-1) showed a 10% increase in grain yield compared to line 203 (with a yield of 5650 kg ha-1). According to the results of line 206, three times the nitrogen split is better, while line 203 two split the nitrogen use.
Keywords: Rice, Nitrogen fertilizer levels, Yield