Impacts of organic input application strategies on soil greenhouse gas emissions in diverse cropping systems in a semiarid region

Abstract

Organic amendments enhance soil quality in agroecosystems, although they may modify the dynamics of greenhouse gas (GHG) emissions, highlighting complex interactions between soil management and environmental sustainability. A field experiment was conducted in the semiarid region of Iran to evaluate the effects of barley residues (BR), sheep manure (SM), and their combination (BR+SM) on soil carbon dioxide (CO2) and nitrous oxide (N2O) emissions under maize and mungbean. In mungbean, both SM and BR+SM resulted in higher CO2 fluxes than BR. Conversely, in maize, cumulative CO2 emissions were similar among treatments. Under mungbean, BR+SM exhibited higher soil N2O values than SM and BR. The lowest cumulative CO2 (4.77 ± 0.24 and 5.29 ± 0.37 Mg ha−1 year−1 for maize and mungbean, respectively) and N2O (4.73 and 3.00 kg ha−1 year−1 for maize and mungbean, respectively) values were measured in the BR, whereas the BR+SM resulted in significantly high cumulative CO2 and N2O under both crops. Cumulative CO2 fluxes were 21.5% and 53.5% lower in the BR than BR+SM under maize and mungbean, respectively. Similarly cumulative N2O was 48% lower in the BR than in the BR+SM treatment under the mungbean cropping system. Application of BR can be considered as an effective alternative management strategy in terms of lowering GHG emissions under maize and mungbean. By exploring the impact of organic input management on soil carbon and nitrogen dynamics in semiarid cropping systems, our study provides key insights for enhancing agricultural sustainability, while reducing GHG emissions.