| Author(s) | Azmi M. Abu-Rayyan* and Nazir A. Al-Hadidi |
| Affiliation | Department of Horticulture and Crop Science, Faculty of Agriculture, University of Jordan |
| Title | Onion Production and Nitrogen Uptake in |
| Source | Journal of King Saud University. Agricultural Sciences. Volume 18, No 1. (2006/1426) |
| Abstract | Two field experiments were conducted during the 2000-2001 and 2001-2002 growing seasons in the Agriculture Research Station of Jordan University, to study the response of 3 onion cultivars from Texas Early Grano 502 (lot No. 222181 from Royal Sluis, lot No. 7A9062/1 from Bakker Brothers and lot No. 96367-73100 from Amsa Seed.moss. main selection) to 6 nitrogen doses and 2 different plant populations in terms of dry qualified yield and nitrogen absorption (kg/ha). The impact of nitrogen waste (kg/ha) in relation to each dose on the environment was also examined. The two plant populations (i.e., 67 and 83 plants/m2) were interacted with the 6 nitrogen doses (i.e., 100, 120, 140, 160, 180 and 200 kg/ha) and with the 3 onion cultivars. Both plant densities produced almost comparable results for almost all dry production components. But, for ecological considerations, the 67 plants/m2 showed better nitrogen absorption and, consequently, showed less impact on the environment as nitrogen waste quantity. This could be also beneficial in reducing the production cost. The 140 kg N/ha showed the highest potential in producing dry yield especially the marketable (1st + 2nd categories) in both seasons. Also, it showed the lowest waste global nitrogen quantity (51 kg/ha). The 150 kg N/ha dose was found to be the closest one to the optimum dose, since the 140 kg N/ha dose gave the best results, but the onion plants still needed 11 kg N/ha, while at 160 kg N/ha about 25 kg N/ha were wasted. For higher doses, the wasted nitrogen space increased as more nitrogen is added and the impact on the environment became heavier. |
