Effects of conservation tillage, controlled traffic and regulated deficit irrigation on soil CO emissions in a maize-based system in Mediterranean conditions.

Conservation tillage is promoted as a potential agriculture practice to reduce carbon dioxide (CO) emissions but little is known on its impact in irrigated Mediterranean conditions, and particularly, when combined with controlled traffic, adopted to avoid soil compaction effects on the crops, and with regulated deficit irrigation (RDI), adopted to conserve water. CO effluxes were measured during the 2016/2017 and 2017/2018 irrigated maize-cropping and fallow periods on a long-term tillage experiment established in Cordoba (Spain) in which two tillage systems, conventional with residues incorporated (CTR) and zero tillage with surface residues (ZTR), are compared, both combined with controlled traffic. Additionally, two irrigation treatments were introduced: full irrigation (FI) and RDI.