Abstract:In order to discuss the effects of different plastic film mulch methods of flue-cured tobacco in production,the field comparison experiment was conducted, studying the effects of unremoved the film during the whole growth period, removed the film at the resettling stage, removed the film at the topping stage, and degradable plastic film mulching on the physicochemical properties of soil, yield and quality of tobacco. The results indicated that the agronomic traits and dry matter accumulation of flue-cured tobacco were closely related to the mulching time and the type of mulching film. The unremoved or removed film in late growth period treatment affects the growth and development of tobacco plants. Removed the film at the resettling stage and degradable plastic film mulching treatment significantly increased the yield and output value of the tobacco leaf compared to unremoved the film, the output increased by 10.66% and 7.38% respectively, and the output value increased by 11 690.46 yuan/ha and 8 940.77 yuan/ha respectively; the mulch removed or using the degradable plastic film mulching could make the better coordination for the tobacco chemical components, and improve the internal quality of the tobacco. Compared with unremoved the film, the soil bulk density of the mulch-removed or degrading mulch treatment was significantly reduced,with a decrease of 6.33%-9.15%, and the soil hardness of the mulch-removed treatment at the resettling stage decreased by 11.59%. The soil alkali-hydrolyzed nitrogen showed a "W" change trend under unremoved the film during the whole growth period. The soil alkaline-hydrolyzable nitrogen was the highest at 30 days after transplanting under the other treatments, and then gradually flattened as the development of growth period. With the development of the growth period, the soil chloride content had no significantly change under unremoved the film treatment, and the soil chloride content decreased under the other removed or degraded the film treatments, compared to unremoved the mulch, removing mulch at the resettling stage with ending the production process could reduce the content of soil chloride ion by 38.55%. By the comprehensive comparison, removing mulch at the resettling stage has the best effect on the soil physicochemical properties and tobacco leaf yield and quality.