Nitrous oxide emissions from soil profiles seeded with pulse crops

Non-Peer ReviewedInoculation of legumes with Rhizobium spp. is a common worldwide agricultural practice that is used to increase crop yield and to improve soil fertility without adding nitrogen (N) fertilizers. There is concern that N2 fixation by legumes enhances emissions of nitrous oxide (N2O) – a powerful greenhouse gas (GHG). The objectives of this experiment were: 1) to measure N2O emissions from soil profiles under inoculated and non-inoculated pulse crops; 2) to investigate the relationship between N2O emissions and N2 fixation by pulse crops. The experiment was carried out in the Phytotron of the University of Saskatchewan with soil flats seeded with inoculated and non-inoculated lentils and peas and fertilized spring wheat. N2O emissions from soil profiles were measured using Profile Gas Samplers (PGS), and were analyzed with a GC. Results indicated that inoculated lentils and peas did not substantially increase N2O emissions, and N2O emissions may not be associated with N2 fixation under the conditions in this experiment