| Abstract: In order to explore the best mulching period suitable for soil moisture preservation and soil temperature increasing in early spring and ensuring the production of dry-land vegetables, combined with the characteristics of dry-land agriculture in Yongdeng county, film mulching period tests of "double ridges and three furrows" in autumn, early spring and pre-sowing were carried out in the dry-land cultivation area of red leaf lettuce. The changes of soil moisture and temperature in different soil layers and the effects of film covering on the growth and yield of red leaf lettuce at different periods were analyzed. The results showed that the moisture content of soil under autumn mulching and early spring mulching was 7.7, 5.5 percentage points higher than that pre-sowing mulching, respectively. At seedling stage, the average soil temperature of autumn mulching and early spring mulching was 1.8 ℃ and 1.3 ℃ higher than that pre-sowing mulching, respectively. Compared with pre-sowing mulching, the seedling stage of autumn mulching and early spring mulching were 4 d and 3 d earlier, respectively, and the seedlings were orderly and strong, and the yield was increased by 13.79% and 10.34%, respectively. According to the actual situation of high-humid mountain area, it was suggested to adopt the early spring mulching. |