论文部分内容阅读
1怎样选择适宜的地膜,其效果如何?答:因种植作物不同,选择覆盖的地膜类型也不一样。如早春露地种植的各种蔬菜,主要以提高地温、保持土壤湿度为目的,应选用白色地膜;初夏保护地(大拱棚、日光温室)覆盖地膜的目的是保持土壤水分,降低空气湿度,减少病害发生,预防后期杂草生长,可选择黑色地膜(特别是草莓喜冷凉,一定要选用黑色地膜);露地夏秋季种植茄果类、瓜类等蔬菜,为了预防病虫害、降低地温,防止杂草等,应选择双色地膜,如银灰色地膜(上面是银灰色,反光避蚜、降低地温;下面是黑色,减少透光,避免杂草生
1 How to choose the appropriate plastic film, the effect of how? A: Due to the different crops, choose to cover the type of plastic film is not the same. For example, all kinds of vegetables planted in open fields in the early spring should be white plastic film for the purpose of raising ground temperature and maintaining soil moisture. The purpose of covering plastic film in early summer protection (large arch shed and solar greenhouse) is to keep soil moisture, reduce air humidity and reduce diseases Occurrence, to prevent the late growth of weeds, black film can choose (especially strawberry hi cold, must choose black film); open field summer and autumn planting solanaceae, melons and other vegetables, in order to prevent pests and diseases, reduce ground temperature and prevent weeds Etc., should choose two-color film, such as silver-gray film (silver above, reflective aphids, lower ground temperature; below is black, reduce light transmission, to avoid weed