For at least 10 years now, agronomists have planted test plots and discussed what the optimum amount of seed per acre to plant corn and soybeans is. Emerson Nafziger, an agronomist from University of Illinois, recently shared some thoughts about planting issues.
Some of the early research seemed to suggest that corn may benefit from higher plant populations. But as further research is done, the benefits of higher corn plant populations have not continued to increase yield as much as some people once thought it would. In large part, that is because hybrids have added more yield per plant, without needing more plants per acre.