The Role of <i>Bacillus subtilis</i>, Planting Dates, and their Influence on the Vegetative and Oil-Growing Qualities of the Soybean Crop

Abstract To investigate the impact of Bacillus subtilis bacteria and planting dates on soybean yield, an experiment was carried out in the fields of the Agricultural Research Station, Field Crops Department, Faculty of Agriculture, Tikrit University for the 2024 season. Randomized Complete Bock Design (R.C.B.D) was used to apply the factors. Bio-fertilization with three levels, 0, 5, and 10 kg ha −1 , and four plant dates include 10 th May, 20 th May, 31 st May, and 10 th June were the experiment factors. The results indicated biofertilizer increased most of plants traits. Planting at 20 th May exhibited higher plant height (152.70 cm), leaf area (6320.55 cm 2 ), height of the first pod (22.25 cm), pod number (174.78 pod plant −1 ), 100 seeds weight (17.57 g), and potassium percentage (2.29%) while planting at 31 st May was significant higher in chlorophyll content (44.83) and phosphorus percentage (1.04%). The interaction between the 20 th May×10 kg ha −1 gave the highest averages in the plant height and leaf area characteristics, where it reached 160.73 cm and 7980.51 cm 2 , and exceeded the 31 st May×10 kg ha −1 was higher in chlorophyll content, where it gave a value of 48.18. As for the trait height of the first pod, it was exceeded by the 20 th May×5 kg ha −1 reached 24.24 cm. The out come of the experiment will be beneficial for the improving soybean production.