$$$$The farmer I worked for has a 100 acre property that he keeps organic. The rest is all conventional. He rotates corn, alfalfa, and beans. The beans fail every year.
You have to plow in the fall to try to get the weed seeds plowed under. In the spring, you have to disc, usually twice, and then take the soil finisher over it right before planting. Post planting and right when the sprouts come out, you need to take the rotary hoe over the field. We would then cultivate every two weeks until the rows filled in. Usually ended up being 4 to 5 times. Then you have to start walking the beans because of middle of the row water hemp or button weeds.
I swear to god we spent more time on 40 acres of beans than we did his other 800 acres of beans. We would no till those and spray twice.