Abstract: 【Objective】To explore the performance of fully biodegradable mulch films and provide a reference for their application in potato cultivation in the northern foothills of the Yinshan Mountains in Inner Mongolia.【Methods】A plot experiment was adopted and four treatments were set：Shanghai Hongrui fully biodegradable mulch film（HRB,white film）,Jinfa science and technology fully biodegradable mulch film（JFB,white film）,conventional polyethylene mulch film（PE）,and no mulch film（CK）. The effects of two fully biodegradable mulch films on the field degradation characteristics,physical and mechanical properties,soil warming and moisture conservation performance,and potato yield formation were analyzed.【Results】Two types of fully biodegradable mulch films showed good physical and mechanical properties,and the HRB and JFB treatments had better effects on soil warming and moisture conservation in the early growth stage of potato. With gradual degradation of the fully biodegradable mulch films,their physical and mechanical properties and soil temperature in the later growth stage of potato decreased gradually,but still met the requirements of temperature,moisture,and mulching during growth and development of potato. Compared with CK,the HRB,JFB,and PE treatments increased the average daily and monthly soil moisture to varying degrees. With increasing mulching time,the HRB and JFB treatments entered an induction period at 50-60 d,and then began to degrade,reaching degradation rates of 86.14% and 83.82%,respectively. As the growth period progressed,the maximum force value and tensile strength of the HRB and JFB treatments decreased to varying degrees compared with CK. Compared with CK,potato yields of the HRB,JFB,and PE treatments increased by 8.82%-29.12%. The yield of the JFB treatment was the highest,at 91.10 t/hm²,and the difference was significant compared with other treatments（P<0.05）. The net profit of the HRB,JFB,and PE treatments was significantly higher than that of CK,and the differences among treatments were significant（P<0.05）.【Conclusion】The Jinfa science and technology fully biodegradable mulch film performs well in soil warming and moisture conservation,physical and mechanical properties,degradation rate,and potato yield improvement. It can reduce farmland mulch film pollution and is suitable for promotion and application in production.

Key words: Fully biodegradable mulch film, Performance evaluation, Potato, Yield