Effects of vermicompost and urea fertilizers on qualitative and quantitative characteristics of Vetiveria zizanioides stapf. grown under drought stress conditions

The use of vermicompost as a bio-fertilizer and urea (as chemical fertilizer) under drought stress conditions was tested in this research. Accordingly, a pot experiment was carried out and the seedlings of vetivergrass (Vetiveriazizanioides stapf.) were grown in the greenhouse at Malayer University. The experiment was conducted based on factorial arrangement in a completely randomized design using five replications. Irrigation levels included field capacity (FC) (as control), 60% FC and 30% FC. Vermicompost applications included zero (as control), 40, and 60% which were expressed as VC1, VC2, and VC3. Urea application levels included zero (0), 100, or 200mg per kg per pot which were expressed as U1, U2, and U3, respectively. The highest and the lowest values of total protein contents (Mg-1 fresh weight (FW)), calcium and magnesium concentrations (mg g(-1) dry weight (DW)), and survival capacity (%) of the vetivergrass were found in the FC x VC3 x U3 and 30% FC x VC1 x U1 treatments, respectively, whereas the maximum and the minimum values of essential oil contents (%) were seen in the 60% FC x VC3 x U3 and FC x VC1 x U1 treatments, respectively. A different trend was seen in the changes of total chlorophyll content (%) values and the highest and the lowest values were found in the 60% FC x VC3 x U3 and 30% FC x VC1 x U1 treatments, respectively. However, the root dry weight increased significantly as the soil moisture content, percentage of vermicompost, or urea addition decreased.