Elevated CO2 reduces nitrate inhibition of N2 fixation in Pisum

Additional carbohydrate supply resulting from enhanced photosynthesis under predicted future elevated CO2 is likely to increase symbiotic nitrogen fixation in legumes.

Pisum sativum
Pisum sativum. Photo by Jun Seita / Flickr.

Butterly et al. use free-air CO2 enrichment (FACE) to study field pea, Pisum sativum, growing under different levels of CO2 and N supply in a semi-arid cropping system and find that increasing N reduces nodulation at ambient CO2 but this inhibitory effect is less under elevated CO2. The results indicate that field pea may perform well in semi-arid agricultural systems under future CO2 concentrations irrespective of soil N status and subsequent gains in N input via enhanced N2 fixation will be important for maintaining the N fertility of cropping systems.

Reference List

Butterly, C. R., Armstrong, R., Chen, D., & Tang, C. (2015). Free-air CO2enrichment (FACE) reduces the inhibitory effect of soil nitrate on N2fixation ofPisum sativum. Annals of Botany, 117(1), 177–185. http://dx.doi.org/10.1093/aob/mcv140