Abstract: This study aims to assess the response of ammonia (NH₃) volatilization to ridge tillage practices in a winter wheat (Triticum aestivum L.) field in the southern Loess Plateau, China. A two-year field experiment was conducted from 2011 to 2013 in the winter wheat growing seasons. The experiment was designed as a split-plot style with tillage practices as main plots. There were three ridge tillage practices and conventional tillage (CT) as the control. Nitrogen application rates were subplots, namely 0 and 180 kg/hm². Ammonia volatilization was trapped using vented acid trapping methods, and ammonium (NH₄⁺-N) was measured using a continuous flow analyzer. Relationships between NH₃ flux and five soil parameters were analyzed by linear regression and stepwise multiple linear regression. The parameters were soil NH₄⁺, moisture, temperature, pH and organic carbon. The results showed that NH₃ flux peaked during the first 10 d following fertilizer application, reduced rapidly in the next 20 d and then leveled off. Ammonia emissions in the ridge tillage systems were on average 5.748 kg/hm²,4.9% less than that in CT (6.05 kg/hm²). In treatments fertilized with 180 kg/hm² nitrogen fertilizer, ammonia emissions averaged 6.512 kg/hm²,6.8% greater than the unfertilized plots. Nitrogen loss rates varied from 0.47% to 1.38%, and the average loss rate in the ridge tillage systems was 60.1% lower than that in CT. Ammonia flux was positively correlated with soil NH₄⁺ and moisture. Ammonia flux was positively correlated with soil temperature and pH from October to December. However, it was negatively correlated with the variables from February to June. Overall, soil NH₄⁺ and temperature were two major factors controlling NH₃ flux in winter wheat fields. The extent of ammonia fluxes linked to soil NH₄⁺ was significantly reduced by ridge tillage practices. Therefore, extending ridge tillage practices is recommended in rain-fed winter wheat production in the southern Loess Plateau to mitigate NH₃ volatilization. Further verifications with multi-location tests could be required to further investigate the effects on NH₃ volatilization of ridge tillage systems and different nitrogen application rates.