Keywords: 
• O₃ /
• dehydrogenase /
• invertase /
• urease /
• total carbon (TC) /
• total nitrogen (TN)

Abstract: Tropospheric O₃ as one of the world's most important atmospheric pollutants, the mechanism of O₃ stress on crop growth, soil enzyme activities and soil carbon and nitrogen content has become the important issues of concern. An ozone-OTCs(OTCs, open-top chambers)system was setup in a winter wheat field to investigate effects of elevated ozone concentration on soil dehydrogenase, invertase, urease and soil carbon and nitrogen content in different soil depths (0-10 cm, 10-20 cm, 20-40 cm) and different growth period (shooting, pustulation period) of winter wheat. The results indicated that soil total carbon (TC) and total nitrogen (TN) in 0-10 cm and 10-20 cm soil layers tended to decrease with the increase of the ozone concentration, and both of which declined significantly in high concentration treatment (120 nL·L^-1) compared to the control treatment. In addition, soil enzyme activities were impacted by elevated ozone. In the pustulation period of winter wheat, the soil dehydrogenase activity reached a maximum when ozone concentration was 120 nL·L^-1, which increased by 59.42% (0-10 cm soil layer), 51.45% (10-20 cm soil layer), 22.16% (20-40 cm layer) compared to control treatment respectively. The soil invertase activity fluctuated in different growing periods of winter wheat and different soil layers. The soil urease activity showed no significant differences in the shooting period under different concentration of ozone; but in pustulation period, the urease activity of 20-40 cm soil layer had a rising trend with elevated ozone concentration, and reached its maximum when the concentration of ozone was 120 nL·L^-1, which increased by 24.55% compared to control treatment. The soil invertase activity and soil total carbon content showed significant relationship, while the soil urease activity and soil total nitrogen content were significantly correlated.