ne of the highlights of the national No-till Conference was listening to Marion Calmer discuss his soybean production methods. Calmer is a manufacturer of narrow row corn heads and an on farm researcher. He uses replicated strip studies to test his ideas and the ideas of others.
I have written several times about soybean population research. The point is that extremely high population soybeans do not provide any economic advantage. In fact, in Calmer's six year study, Yields were nearly the same no matter what population he planted. He admitted that he is reluctant to plant less than 75,000 plants even though his research would support as low as 50,000 plants per acre. For every increase in population by 25,000 plants per acre he says it costs an additional $10 per acre with no return. If you are looking to save money in the coming year, look at cutting back populations. If 75,000 plants per acre makes you nervous, try cutting back 25,000 from wherever you are.
He also compared 30 inch rows to 15 inch rows. The 4 bushel per acre advantage of 15 inch rows is huge. If you are still planting 30 inch row soybeans it is a costly production method. He admitted that there might be an additional gain of 1 bushel per acre if the soybeans were drilled. A few years back he was drilling his production acres. He has switched to 15 inch rows in the past few years.
