I think we are so far from optimizing soybean yield yet that spacing is not a problem. Many yield winners still use drill and spill. If I could plant all my beans in 30 inch rows by May 5, I would optimize sunlight to row. Since my post below shows how seldom that is, a 15 inch row planter is probably number one here. Because of many circumstances, the drill is the best option for me. I think I have planted soybeans, my number one cash crop, more often after May 5 than before May 5 here. Canopy helps my weed control which is important here. The row unit is very important and my ideal would be a White 30 inch row unit modified with MartinTill Planted by May 1. I can't do that very often so I don't do it. Next best is a 15 inch row planter here but I have beaten 15 inch rows with 7.5 inch drilled rows many times. The easiest thing for me to do for higher yields is planting with a notill drill. It is probably more my personality. Ed Winkle |