This is wheat country and producers are likely to want to apply fertilizer with seed as a matter of course. However, it is just beginning to be learned in the new expanding northwest territories of soybean production. Soybeans cannot tolerate fertilizer with the seed, especially when it is concentrated in row widths of greater than 15 inch spacings. There are numerous studies, however, to suggest that soybeans prefer fertilizer broadcast rather than band. Since soybeans require little supplemental P fertilizer at medium or higher soil test levels, the recommendation is to forego fertilizing beans unless the soil test P level is very low or low and instead add the recommended fertilizer to crops before or following soybeans that tend to respond more.
Soybeans are a good scavenger of P, unless soil test levels are very low or low.
If P needs to be applied, it would not be unlikely to expect 2-3 bushels more soybeans if the fertilizer was broadcast rather than banded. Some of this increase may be because soybean roots are sensitive to salt and may shy away from banded fertilizer instead of utilizing it. Another reason suggested is that the soybean roots need to be bathed in nutrients, and are inefficient in picking up the concentrated bands. Therefore broadcast is better than banded. Take note of the soil test P level to determine if you really need the P this year at all.