Abstract:The tobacco variety CS80 was used as the material, 4 kinds of biodegradable mulching films(T1, T2, T3, T4) were selected, and polyethylene(PE) film was used as the control(CK). The films were mulched on March 8th, and the tobacco seedlings were transplanted on March 25th. The degradation characteristics of the films were recorded by taking photographs with a camera at fixed points, and the temperature in the top 10 cm soil layer was continuously measured by a GPS temperature recorder. The plant height, stem circumference, maximum leaf length, maximum leaf width, maximum leaf area, pitch and number of leaves were measured 45 d after transplanting and the soil pH, organic matter, total nitrogen, total phosphorus, total potassium and effective phosphorus, urease, sucrase and β-glucosidase activities were measured 45 d and 105 d after transplanting, so as to comparatively analyze the degradation characteristics of the films and the effects of mulching on the growth of tobacco and the physicochemical properties of the soil. The results showed that T1 degraded the fastest and started to degrade at 70 d after mulching, and T3 degraded the slowest and started to degrade at 85 d after mulching; at the end of mulching, the degradation level of the 4 types of biodegradable mulching films reached above grade 5, and the effect of increasing temperature and preserving moisture was similar to that of the PE mulch; compared with the CK treatment, at 45 d after transplanting, mulching with T2, T3, and T4 increased the height of the plant, the maximum leaf length, and the maximum leaf area; T2 mulching increased the yield by 0.8% compared with that of CK, and the yields in T1, T3 and T4 treatments were reduced by 41.6%, 25.5% and 5.9% respectively, compared with that of CK; the production value of T1 and T4 mulching treatment increased by 8.7% and 6.6% respectively, compared with that of CK, and the yields in T1 and T3 mulching treatment decreased by 37.6% and 17.6% respectively, compared with CK; mulching with T2 and T3 decreased soil organic matter, total nitrogen and effective phosphorus contents as well as soil urease andβ-glucosidase activities, and increased total potassium content and sucrase activity at 45 d after transplanting. In conclusion, agronomic traits, yield and production value of T2 mulching treatment were better than those in other treatments, indicating T2 has the potential to replace PE.