Crop Water Requirement and Field Environment under Plastic Film Mulch Cultivation

Because of heat transfer from soil to atmosphere is reduced during night time, the temperature in surface soil layer in plastic film mulched field is higher than that in non mulched field. The temperature raising effect is remarkable in seedling stage with a very low cover degree. Because of plastic film is very effective in reducing soil surface evaporation, crop water requirement in plastic film mulched field is less that that in non mulched filed. The ET values in plastic film mulched cotton and corn field are 73.6 mm and 60.1 mm less than that in non mulched field for the whole growing season respectively.