Assessing the influence of row spacing on soybean yield using experimental and producer survey data
J.F. Andrade, M. A. McClure, J. Edreira, S. Mourtzinis, S. Conley, I. Ciampitti, J. Dunphy, J. Gaska, D. Holshouser, L. Lindsay, and C. Lee.  2018.  Field Crops Research.

Abstract:
Narrowing row width in soybean fields leads to earlier canopy closure, which may increase capture of solar radiation during critical crop stages for yield determination.