Effect of organic and bio fertilization and magnesium foliar application on soybean production

Egypt has paid great attention to expanding the cultivation of oil crops such as soybean by developing plans and strategies, including the research plans, which were developed by the Agricultural Research Center. These plans aim to increase the areas cultivated with oil crops and simultaneously raise the productivity of the cultivated unit. Bio-fertilization increases the flowering of microbial activities in the soil and improves plant growth, while organic fertilization is environmentally beneficial. On the other hand, magnesium (Mg) is included as a co-enzyme with enzymes that build vegetable oils and fats. To improve soybean production, two field experiments were carried out aiming to assess six treatments of organic and bio fertilization [T1: Control (without), T2: Rhizobium (RH) alone at rat of 1.0 g per 1.0 kg seeds, T3: Farmyard manure FYM (cow waste) alone at rate of 36.0 m3 ha-1, T4: Plant compost PC (sugar cane and banana residues at ratio of 50:50) alone at rate of 36.0 m3 ha-1, T5: T2+ T3 (RH+ FYM) and T6: T2+ T4 (RH+ PC)] as main plots. While the sub-main plots were assigned for foliar application of Mg [F1: Control (without foliar application) and F2: Mg sprayed at rate of 1440 g fed-1 using magnesium sulphate (MgSO4, consisting of 20.19 Mg2+ % by mass)]. The main results showed that the superior treatment for obtaining the maximum values of growth performance e.g., plant height (87.16 and 88.12 cm, for 1st and 2nd seasons, respectively), dry weight (14.99 and 15.18 g, for 1st and 2nd seasons, respectively) and chlorophyll (46.22 and 47.41 SPAD, for 1st and 2nd seasons, respectively) was the T6 treatment (combination of RH and PC) followed by T5 treatment (combination of RH and FYM) then T4, T3, T2 and T1, respectively. The same trend was found also for all parameters which expressed quantitative and qualitative yield of soybean e.g., No. of pods plant-1, seed yields, oil, protein and carbohydrates, where the T6 treatment came in the first order, while the T1 treatment came in the last order. Regarding the magnesium treatments, the plant growth performance, quantitative and qualitative yield significantly increased with Mg foliar application (F2) compared to the corresponding soybean plants grown without Mg addition (F1). Generally, it can be concluded that the inoculation of soybean seeds with rhizobium inoculant before cultivation with the soil addition of plant compost (sugar cane and banana residues at a ratio of 50:50) and simultaneously treating the grown plants through their life period with magnesium is the best-combined treatment which will achieve the highest plant growth performance, quantitative and qualitative yield of soybean and will meet people's needs for strategic oil crops.