عبد القادر السنوسي, السنوسي2025-09-052025-09-052023https://dspace.omu.edu.ly/handle/123456789/490Two field experiments were conducted at two different sites (regions), namely Al-Wesaita that situated between latitude 21° 42′ N, and longitude 32° 43′ E, (275) meter above the sea level, and El-baida which located which between latitude 21° 44′ N, and longitude 32° 45′ E, (540) meter above the sea level, during the growing season (2020-2021). This work was undertaken to investigate the effect of sowing methods (drilling and broadcasting), nitrogen fertilizer levels (0, 100, 150 200 kg/N/ha, in the form of Urea (46%N) the growth and yield production, and yield components of Barley (Hordeum vulgare L.) (Var.Rayhan). Both experiments laid out as split-plot design with three replications, The experimental unit was 2×2 m (4m²). The two sites were well prepared by plowing, harrowing, leveling, and compacting of the soil, the date of planting was the last week of Novemer, 2020, planting method was on rows, (15cm) apart and (4m) long for each experimental unites for both sites. Measurements of the growth characters were performed on ten samples chosen randomly from each experimental unit from the two experiments, these agronomic characters included, plant height (cm), number of total tillers/m², number of tillers non bearing spikes/m², number of tillers bearing spikes/m², number of spikes /plant, number of grains / spike, dry weight of spike (g), spike length (cm), dry weight of grains/ spike, dry weight of 1000-grains, biological yield (t/ha-¹), grain yield (t/ha-¹), straw yield (t/ha-¹), harvest index, and protein content of grain. Data of each agronomic character analyzed separately using Gen- stat program and the Least Significant Difference (L.S.D) method was used for the comparison among means. The results obtained from the two experiments summarized as follow: A- The effect of nitrogen fertilizer: Results showed that nitrogen had a significant on all agronomic characters tested in this investigation for the both sites (El-Baida and Al-Wesaita) levels had a significant effect on most agronomic characters tested in this investigation for the both sites. However, at El-Baida region plant height, number of tillers non bearing spike / m², number of spike /plant, dry weight of spike, spike length, dry weight of 1000-grains, and harvest index showed no significant difference. In contrast, at Al-Wesaita region, adding nitrogen fertilizer had significant and high significant impact in most the agronomic characters tested in this experiment, except number of tillers non bearing spike and harvest index. However, crop chracters such as number of tillers bearing spikes/m², number of grains / spike, dry weight of grains/spike, biological yield (t/ha-¹), grain yield (t/ha-¹), and straw yield (t/ha-¹)showed high significant response and had been increased significantly when nitrogen fertilizer. B- The effect of planting methods: At El- Baida site, planting methods showed no significant effect onmost agronomic characters, except forbiological yield grainyield and straw yield.Differences of the other agronomic characters did not the levels of significance. In contrast, at Al-Al-Wesaitadifferent planting methods had significant differences in plant height, number of spike /plant, and high significant differences on number of grains/spike, biological yield, and grain yield, other agronomic charactersinclude, number of total tillers/m², number of tillers non bearing spikes/m², number of tillers bearing spikes/m²spike, dry weight of spike, spike length, dry weight of grains/ spike, dry weight of 1000-grains, straw yield, and harvest index showed no significant differences due to the effect of different methods of planting. Crop characters at Al-Al-Wesaita region had more response to adding nitrogen fertilizer and gave higher values more than barely plants grown at El- Baida region. Panting by drilling methods had the heights values for most crop characters tested in this study, compared byotherThesis