Soybean Biomass and Nitrogen Accumulation Rates and Radiation Use Efficiency in a Maximum Yield Environment

Abstract

ABSTRACT Soybean [ Glycine max (L.) Merr.] physiological characterization in a maximum yield environment may identify yield‐optimization factors, lead to reassessment of fundamental crop model parameters, and provide guidance for management or breeding efforts. From 2011 to 2013, we characterized biomass and N accumulation rates, radiation use efficiency (RUE), and yield for four or five cultivars in a maximum‐yield contest field. Grain yield among cultivars ranged from 5290 to 7953 kg ha −1 . The highest yields were observed in 2013, when biomass and N accumulation rates ranged from 45.6 to 64.3 g m −2 d −1 and 1.43 to 2.08 g N m −2 d −1 , respectively, and when RUE values ranged from 1.46 to 1.89 g MJ −1 . The observed crop growth characteristics in 2013 were near or above the maximum values previously reported in the literature. These empirical measurements provide collateral data documenting a soybean crop with grain yields approximately 6719 kg ha −1 .