Carbon dioxide and methane fluxes from legumes based rotations under conventional and organic practices

Resumen

In this study we assessed the effect of two different rotations based on winter (faba bean) or summer (cowpea) legumes on the direct emissions of CO2 and CH4. Faba bean was rotated with the summer melon crop (Cucumis melo) while cowpea was rotated with the winter broccoli crop (Brassica oleracea). We also assessed if different legume cultivars and management practices (conventional and organic) significantly influenced gas emissions. The study was randomly designed in blocks with four replications, in plots of 10 m2, during two complete cycles. Gas samples were taken in different times (0, 30 and 60 minutes) once a week using the static gas chamber technique for each crop. Results showed that cumulative CO2 emissions in broccoli decreased after the rotation with both cowpea cultivars under conventional management practices. Faba bean cultivars and management practices had no influence on cumulative CO2 emissions in melon crop. Cumulative CH4 emissions in broccoli crop were lowest after the rotation with Grey-eyed pea than Black-eyed pea cultivar, under both management practices. However, faba bean cultivars and management practices had no influence on cumulative CH4 emissions in melon crop. Cumulative CH4 emissions in melon crop were highest than in the rest of crops. Cowpea cultivar and management practice influenced cumulative CH4 and CO2 emissions of broccoli crop, respectively. Faba bean cultivar and management practice had no effect on cumulative CH4 and CO2 emissions of melon crop. Acknowledgements: This research was financed by the FP7 European Project Eurolegume (FP7-KBBE-613781).