对塑料大棚下的土壤进行了定位观察,发现棚内土壤表层盐分含量普遍高于露地土壤。盐分含量的提高与建棚年龄有关,栽培了五年的大棚土壤,表层盐分含量比露地增加了4—5倍;盐分的运行与土壤水分变化密切相关,夏季揭棚后,承受了雨水淋洗,脱盐也比较明显,但并不彻底淡化,日后覆棚栽培时就会回升。大棚土壤表层积聚盐分的根本原因有:蒸发量高出露地1—2倍;水分基本上由下而上的运行;施肥过多,造成养分失调,N0_3~-含量达到为害程度。控制施肥量,调节灌、排水,制约土表水分蒸发是解决塑料大棚土壤盐分积聚为害作物的主要措施。 The plastic greenhouse under the positioning of the soil were observed and found that shed greenhouse soil salt content is generally higher than the open field soil. The increase of salt content was related to the incubation period. Five years cultivation of greenhouse soil resulted in the increase of surface salt content by 4-5 times compared with that of open field. The operation of salt was closely related to the change of soil moisture. After summer shedding, , Desalination is also more obvious, but not completely desalination, the future cover cultivation will rise. The root causes of accumulation of salinity in the greenhouse soil surface are as follows: the evaporation is 1-2 times higher than that of the open field; the water basically runs from bottom to top; excessive fertilization results in nutrient imbalance, and the content of N0_3 ~ reaches the damage degree. Controlling the amount of fertilizer, regulating irrigation and drainage, restricting the evaporation of soil surface water is to solve the plastic greenhouse soil salinity accumulation of harmful crops as the main measures.