Just one man's opinion but you asked.

I would double treat, done it many times.

I have had increases as high as 8 bu per acre when it was in soy the year before. You could see 15 in your situation.

Show us a picture of big pink and red nodules as big as your finger nail.

Take a tissue test at first bloom or earlier, like the first trifoliate and see what your nutrient load is.

Ed Winkle