Abstract: In order to explore better plastic film mulching cultivation methods for peppers in open fields in northern Jiangsu Province, the commonly used local variety Sujiao No.5 was used as experimental material. Two plastic film mulching cultivation methods were set up, including plastic mulching only on the ridge surface（T₂）, and the ridge and furrow with plastic mulching on whole ground（T₃）. Taking no plastic mulching（T₁）as the control （CK）, the effects of different plastic film mulching cultivation methods on the growth, yield, soil nitrogen, salinity, and pH of peppers in open fields were studied. The results showed that compared to T₁ treatment, T₃ treatment could advance the initial flowering, fruiting, and harvesting stages of peppers by at least 5 days, and significantly improve the quality and yield of fresh peppers by 18.95% and 11.99%, respectively; at the seedling stage, flowering and fruiting stage, and maturity stage, the pepper plant height of T₃ treatment was significantly higher than that of T₁ treatment by 34.28%, 30.30%, and 16.66%, respectively, and the pepper plant stem diameter was significantly higher than that of T₁ treatment by 42.75%, 26.79%, and 26.64%, respectively; in the mature stage, the unfolding degree of T₃ treatment could reach 78.9 cm×81.2 cm, and the aboveground dry mass was significantly higher than that of T₁ and T₂ treatments by 24.35% and 12.01%, respectively. During the flowering and fruiting period, the soil TN content of T₂ and T₃ treatments was significantly lower than that of T₁ treatment by 5.77% and 24.04%, respectively. The soil available nitrogen content was significantly lower than that of T₁ treatment by 12.99% and 12.27%, respectively; during the seedling and maturity stages, the water-soluble salt content of 0~20 cm soil layer treated by T₃ treatment was significantly lower than that treated by T₁ treatment by 85.26% and 17.35%, respectively.

Key words: pepper, plastic film mulching, growth period, yield, soil nutrients, northern Jiangsu Province