CO2 evolution from a ridge tilled and a mouldboard ploughed Luvisol in the field

This field study was initiated to measure soil CO2 evolution of the Turiel ridge tillage system under faba bean (Vicia faba L.) compared with mouldboard ploughing. The CO2–C measurements were done in situ with a transportable infrared gas analyzer at different positions on the ridges and furrows and on mouldboard plough plots with and without vegetation, respectively. The CO2 evolution at different ridge positions reflected a ridge pattern with a CO2–C evolution in the order crown > shoulder > furrow. On a hectare basis the mouldboard ploughed soil evolved 0.11 t more CO2–C ha−1 than ridges, and the plots with vegetation evolved 0.58 t more CO2–C ha−1 than the plots without vegetation during the investigation period of 57 days. At higher air temperatures the soil temperature tended to be higher on ploughed plots compared to ridges. The CO2 evolution on the planted plots decreased with time, reflecting the decreasing physiological activity of the plant roots. Overall, despite a high degree of soil disturbance, the amount of CO2 evolved from the ridge tilled soil was lower compared to mouldboard plough tillage, probably reflecting less favorable conditions for soil microorganisms in the ridges compared to the ploughed soil.