Abstract:There are some troubles in the well-channel engineering in Inner Mongolia Hetao Irrigation District due to the temperature of well water is low than that of the Yellow river water in the crop growth period. In this paper, automatic monitoring soil temperature at depth of 5, 15, 25 and 40 cm inside and outside mulching film were carried out in the maize fields which were surface irrigated with Yellow river water (H), well water (J) and drip irrigation with well water (D), in order to characterize the 10 d and diurnal changes of soil temperature at 5 cm depth inside mulching film, before and after irrigation and its response to air temperature. The results showed that 10 d soil temperatures of H and J at 5 cm depth responded to air temperature significantly, yet D failed due to the frequent irrigation; The hysteresis effect was apparent in soil daily temperature with increasing soil depth, H (J) was delayed by 2.7 h but D delayed by 2.4 h per 5 cm increment of soil depth from 0 to 40 cm, and air temperature changes significantly affected the diurnal variation of 0 – 40 cm soil temperature. In mid to late June, H significantly promoted soil temperature of crop root zone (40 cm), J reduced soil temperature, D influenced soil temperature severely but shortly. The response of soil temperatures at 15 cm and 25 cm depths of H and J to air temperature after irrigation were significantly different with that before irrigation, while D was significantly different at 25 cm depth. On the whole, D with mulching film responses fast to air temperature and soil temperature is higher than H and J in maize seedling stage, so it is feasible for maize irrigation in well-irrigated areas of Hetao irrigation region.