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.
Nitrogen + Azotobacter biofertilizers, sorghum cultivars, genotype by fertilizer interaction, NPK content, protein
Biofertilizer Azotobacter positively affected almost all the traits except the carbohydrates. The sorghum cultivars varied significantly for the study traits. It is also possible to reduce the use of chemical fertilizers by replacing them with biological fertilizers.