| Effects of common plastic film, biodegradable film, liquid film and straw mulching on tilth soil temperature and maize emergence were observed under planting pattern of ridge and ditch.Two-year results showed that common plastic film and biodegradable film mulching could improve significantly the soil temperature.The average temperature in 5～25 cm tilth soil under common plastic film and biodegradable film mulching were 2.51℃～3.77℃ and 1.30℃～2.19℃, respectively, which is higher than that of the uncovered ground.The difference between the liquid mulching and control is very little with the warming value of 0.13℃～0.56℃.Straw mulching could reduce soil temperature, and the tilth soil temperature were 1.25℃～2.19℃ which is lower than that of the control.Maize emergence were promoted 2 d and 1 d earlier under common plastic film and biodegradable film mulching, respectively, but was delayed 1d under straw mulching, and showed no difference under liquid film mulching as compared with the control. |