Abstract: The double ridge plastic mulch cropping technique has been widely adopted since 2010 for maize and potato production across 8 provinces and autonomous regions of northeast, north and northwest China with lower rainfall. The plastic film blocks moisture evaporation from soil and channels precipitation into the sowing trench between the ridges, so increasing soil moisture level around the crop roots, as well as assisting with weed control and modifying soil temperature. Yields can be increased by up to 30% with considerable economic benefit. This research compared the performance of white (Control) and black plastic film as the soil cover, since there is little available data on whether plastic film color affects the soil moisture and temperature beneath, and crop performance. In this research soil moisture and temperature were measured weekly over the growing season from early April to mid July, and weed biomass data, and crop agronomic and yield were collected on relevant dates. Soil moisture was measured for 5 soil depths: 0-20, 20-40, 40-60, 60-80, and 80-100 cm, and soil temperature for 5, 10, 15, 20, and 25 cm soil depths. Typical values for soil moisture were 18%-20% in April, 20%-22% in May and 16% in June, without major variation across soil depths. In the 0-20 cm layer soil was 1%-2% drier under black film than under white film in April, but this gradually reversed and soil had 2% higher moisture content under black film in June. In the deeper soil layers (except 80-100 cm), soil moisture (%) was identical under black and white film in April, but by June was 1%-2% higher under black film than white film. Soil temperatures ranged from 12-18 ℃ at the start of the experiment to 25 ℃ in June, and except for the 10 cm soil depth, were consistently lower under black film than white film by over 2 ℃ in April, reducing to 0.5 ℃ lower under black film in June. Weed densities in June were 150 and 3 plants/m² under white film and black film, respectively. Crop agronomic data generally did not differ significantly with film color, but yield was 5.4%-9.5% higher when maize was planted on black film.