|Awad, M -|
|Abd El-Kader, A -|
|Attia, M -|
Submitted to: International Journal of Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 21, 2011
Publication Date: December 14, 2011
Citation: Awad, M., Abd El-Kader, A.A., Attia, M., Alva, A.K. 2011. Effects of nitrogen fertilization and soil inoculation of sulfur oxidizing or nitrogen fixing bacteria on onion plant growth and yield. International Journal of Agronomy. DOI: 10.1155/2011/316856. Interpretive Summary: Adequate nitrogen (N) and sulfur (S) availability is critical for optimal onion yield and quality. This field experiment was conducted in El-Giza governorate in Egypt. Treatments included different N Rates (either 62, 124, or 248 kg/ha) with or without S-oxidizing bacteria. Additional treatments included no N or S-oxidizing bacteria, and no N but inoculation of S-oxidizing and N fixing bacteria. All treatments received 620kg/ha elemental S. Onion yield increased by 28 to 76% with increasing N rates from 62 to 248 kg/ha as compared to the yield with no N application. N uptake also increased by 61 to 145%. Onion yield increased by 3.2 fold with inoculation of S-oxidizing and N fixing bacteria as compared to that in control soil.
Technical Abstract: A field experiment was conducted in a newly reclaimed soil at El-Saff region, El-Giza Governorate, Egypt to study the effects of different rates of nitrogen (N;62 to 248 kg ha-1) with or without soil inoculation of sulfur (S) oxidizing bacteria (SoxB), and combined inoculation of SoxB and N fixing bacteria (NFxB) on yield, quality and nutritional status of onion (Allium cepa L., ‘Giza 20’). Elemental S at 620 kg ha-1 was applied to all treatments. Application of N at 62, 124, and 248 kg ha-1 rates increased onion yield, plant height, and N uptake by 28 to 76 %, 32 to 53 %, and 61 to 145 %, as compared to those of the plants that received no N. Inoculation of SoxB at various N rates increased onion yields by 47 to 69% and N uptake by 76 to 93 % as compared to those of the plants which received the respective rate of N but no SoxB inoculation. Inoculation with SoxB and NFxB increased onion yield by 221%, plant height by 62%, and N uptake by 629% as compared to those of the plants grown without inoculation and no N applied.