NITROGEN AND BIOFERTILIZATION EFFECTS ON BIOCHEMICAL, QUALITATIVE, AND PHYSIOLOGICAL TRAITS OF SORGHUM (SORGHUM BICOLOR L.)

A field experiment done in the spring of 2022 on Sorghum bicolor L. cultivars with different nitrogen and biofertilizer fertilizer regimes proceeded at the Ibn-Al-Bitar Vocational Preparatory School, District Al-Hussainiya, Holy Governorate of Kerbala. Sowing in a randomized complete block design (RCBD) with a factorial experiment and three replications took place in the third week of March 2022, and harvesting in the third week of July 2022. The trial included two factors; the first had three sorghum cultivars (V1 = Al-Khair, V2 = Rabeh, and V3 = Bohuth 70). The second factor was combinations of nitrogen and biofertilizers, i.e., F0 = the complete dose of nitrogen fertilizer (320 kg N ha-1); F1 = 3/4 nitrogen fertilizer + Azotobacter; F2 = 1/2 nitrogen fertilizer + Azotobacter; F3 = 1/4 nitrogen fertilizer + Azotobacter, and F4 = Azotobacter with no nitrogen fertilizer. The results showed the superiority of cultivar Bohuth 70 for the traits yield per plant (116.2 g plant-1) and nitrogen, phosphorus, and protein percentages in grains (2.212%, 0.3212%, and 13.82%, respectively). Cultivar Al-Khair excelled in total chlorophyll, ash, and potassium percentages in grains (1.057 mg g-1, 2.165%, and 2.085%, respectively). As for the interaction, the combined treatments V3F0 excelled in the traits of yield per plant (134.4 g plant-1), nitrogen (2.610%), and protein percentages (16.31%), while the interaction of V1F3 performed better for the variables ash and potassium percentages (2.600% and 2.160%, respectively). However, the reaction of V3F1 surpassed phosphorus and potassium percentages (0.3615% and 2.160%). The research happened to know the extent to reducing the quantities of recommended chemical nitrogen fertilizers and their effect on the qualitative.