Micronutrients Impact on Soybean (Glycine max (Merrill)) Qualitative and Quantitative Traits

In order to study the effects of applying the micronutrients zinc, manganese, and boron, and to compare the effects that incorporating them in the soil and spraying them on the crop on seed oil and protein contents and percentages, a study was conducted based on the factorial design with the two factors of incorporating these micronutrients in the soil and spraying them on the crop, in 16 treatments and four replications (a total of 64 trials), in 2009-2010 in Dasht-e-Naz in Sari of northern Iran. The treatments were as follows: T1=control, T2=Znf, T3=Mnf, T4=Bf, T5=Zns, T6=Zns+Bf, T7=Zns+Mnf, T8=Zns+Znf, T9=Mns, T10=Mns+Bf, T11=Mns+Mnf, T12=Mns+Znf, T13=Bs, T14=Bs+Bf, T15=Bs+Mns, T16=Bs+Znf. Results obtained showed that the highest seed oil percentage (25.03%) was achieved by spraying zinc on the crop, and that the biggest seed oil yield (359.31 Kg.h) was obtained by applying manganese to the soil. Results of the comparison of the means indicated that the highest seed protein content (36.12%) was achieved by spraying boron on the crop, and the greatest seed protein yield (545.54 Kg.h) was obtained when manganese was added to the soil. These results also showed that the largest number of total pods per plant (71.05), and the biggest seed yield (152.9 g.m-2) were achieved by applying manganese to the soil. In the comparison of the interaction effects of the data, it was also shown that, although the highest seed oil percentage belonged to the spraying of zinc on the crop, yet the greatest seed yield among all the treatments (170.7 g.m-2) was that of the treatment of adding manganese to the soil plus spraying zinc on the crop, in which the greatest number of pods per plant (77.87) and the highest seed protein yield (631.1 Kg.h) and the highest seed oil yield (284.5 Kg.h) were obtained.