Producers want to know how cover crops might be able to be used in semiarid regions to enhance soil nutrient cycling and water productivity. In an experiment involving limited irrigation of cropping systems in Clovis, NM, we evaluated the effect of cover crops on soil carbon dioxide (CO2-C) emissions. Higher emissions indicate greater soil biological activity. Our results showed higher carbon dioxide emissions from cover cropped field plots compared to fallow plots. Seasonal changes in carbon dioxide emissions varied with cover crops and peaked with the interaction of soil temperature and moisture following precipitation events. Peas used as a single-species cover crop or mixtures of pea-canola, pea-oat-canola, or a six-species mix increased carbon dioxide emissions whereas canola by itself and pea-oat mixture reduced emissions during periods of higher precipitation. Carbon dioxide emissions from canola and pea-oat mixtures had lower emissions than the other cover crops planted for this study.
Publication: Nilahyane, A., Ghimire, R., Thapa, V.R., Sainju, U.M. (2019). Cover crop effects on soil carbon dioxide emissions in a semiarid cropping system. Agrosystems, Geosciences & Environment. 3(1):2020. Open access.