1) How long would it take you to plant an acre of corn with that?
2) Guys asking about Beans on Beans..... 2 Years of different types of beans (different brand or #) is all I will do. Could you do 3, sure, probably. What folks often don't realize... You are setting yourself up for some nasty disease with consecutive bean plantings. Fungus for example. Some guys go with some fungicides to combat this but it's still not a good idea. Corn to bean to corn to bean rotation is in place for very good reason. Beans are much riskier to do year after year VS corn. You could essentially (in a bad case) make your ground screwed for future beans for a long time if you did it too long. 2 years is ok, 3 years is risky (I've done it on rare occasion), 4 years, no way, I would never do it. I'll do 2 max. Other downsides to beans on beans..... Erosion is worse. Weeds, etc (good call on Liberty beans). Beans fix N, corn eats it up the following year and keep many diseases out. Hope that answers previous questions. Do some sort of rotation and don't risk pushing the limits on beans. Another option on a rotation is rotating out a Dbltree mix after beans, like turnips/radishes (which will utilize N as well) or the grain mix.