Historical Soybean Study: Grain Filling × Nitrogen Fixation

Authors

S. Tamagno, Kansas State UniversityFollow
I. A. Ciampitti, Kansas State UniversityFollow

Keywords

soybean, BNF, nitrogen, genetic gain, seed weight

Abstract

Genetic gain is characterized by comparing the performance of genotypes from a different year of release. Historic studies are useful to understand changes in yield-related traits that also contribute to yield potential. This study aims to quantify yield improvement for soybean through a set of seven genotypes with different years of release, and their respective numerical components, with a focus on final seed weight generation under two different nitrogen (N) conditions. Changes in biological N fixa­tion (BNF) were quantified during the seed-filling period (SFP). Non-linear models were fit to the data to characterize seed weight and BNF changes throughout the SFP. Genetic gain led to an overall yield increase of 0.49 bu/a/year mainly explained by increases in the seed number rather than seed weight. Nitrogen application increased yield equally across genotypes (P<0.01), and final seed weight in all genotypes tested. Biological nitrogen fixation activity was reduced by 44% at the onset of the SFP, however, no N deficiencies were observed.

Recommended Citation

Tamagno, S. and Ciampitti, I. A. (2019) "Historical Soybean Study: Grain Filling × Nitrogen Fixation," Kansas Agricultural Experiment Station Research Reports: Vol. 5: Iss. 6. https://doi.org/10.4148/2378-5977.7780