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上海市郊菜区现有塑料大棚约1万亩,预期1992年前后将发展到2万亩左右,菜农十分重视大棚蔬菜生产.大棚条件下的温、湿、光照条件及水肥管理措施与大田有所不同.这些与大田不同的条件,常易导致作物较普遍的生理障碍与病害的蔓延.主要由于连续上升水流的影响,表土易于积盐,严重者可成片表现盐斑、盐花,甚至盐害.由于特殊的耕作(浅耕及碎土不好)、灌水(常表土湿润)、施肥(养分积聚表土)及无天然雨水淋洗.表土易于板结.
The existing plastic greenhouse in the suburbs of Shanghai has an area of about 10,000 mu and is expected to grow to around 20,000 mu around 1992. The vegetable growers attach great importance to the production of greenhouse vegetables. The conditions of temperature, humidity and light in the greenhouses, Different from the field conditions often lead to more common physiological obstacles to crops and the spread of diseases, mainly due to the continuous rise in water flow, surface soil easy to accumulate salt, severe cases can be expressed as a piece of salt plaque, salt flowers, and even salt Harmful because of special tillage (poor tillage and broken soil), irrigation (often topsoil wetting), fertilization (nutrient accumulation of topsoil) and leaching without natural rain.