Nitrogen and phosphorus uptake and nitrogen fixation estimation of faba bean in western Canada

Abstract

AbstractFaba bean (Vicia faba L.) has very efficient dinitrogen (N2) fixation, the greatest among grain legumes. The main aims of this study were to investigate the effect of nitrogen (N) and phosphorus (P) fertilizers on yield, N and P uptake, and biological nitrogen fixation (BNF) potential of faba bean. Four faba bean cultivars (‘CDC Snowdrop’, ‘219‐16’, ‘Snowbird’, and ‘Tabasco’) were grown in a 2‐yr field experiment at four site‐locations in Saskatchewan, Canada, during 2016 and 2017. In addition, a controlled‐environment study was also conducted to address how P fertilization influences growth and proportion of nitrogen derived from the atmosphere (%Ndfa) through BNF in 2017. Yield was not significantly affected by cultivar, fertilization or site‐location, however, N and P uptake were significantly affected to varying degrees by all three effects. The average faba bean grain yield was 5,280 kg ha–1 in field experiments. Average grain N uptake (117–300 kg N ha–1) and P uptake (15–35 kg P ha–1 and 34–80 kg P2O5 ha–1) were significantly greater than straw N and P uptake in the field. An estimated 88% Ndfa was obtained in the controlled‐environment study and 230 kg N ha–1 of N uptake was observed in aboveground biomass (grain and straw) in the field experiments. Results support the efficiency of N2 fixation in this species in western Canada.