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延庆县地处北京西北部的塞外,是一个三面环山,一面临官厅水库的盆地.气候及降水变化与北京其它大部分地区不尽相同,主要是降水量和热量明显偏少.粮食作物以一年一熟为主,是本市重要的商品玉米基地.大部分是旱地.粮田40万亩,其中春玉米种植面积30万亩,面积和产量均占全县的70%以上.要提高全县粮食产量,首先必须提高玉米的生产能力,而延庆的30万亩春玉米,有近20万亩分布在旱地上,不能灌溉,完全靠天然降水维持玉米的生产.因此,在研究提
Yanqing County, located in the northwestern part of Beijing, is a basin surrounded by mountains and facing the Guanting Reservoir.Climatic and precipitation changes are not the same as those in most other areas in Beijing, mainly due to the obvious precipitation and heat loss. The main one of a year is the city’s major commodity base of corn, most of the dry land .40 million mu of grain fields, of which 30 million mu of spring corn acreage, the area and output accounted for more than 70% of the county. In the whole county, the output of corn must first increase the production capacity of corn. However, nearly 300,000 mu of spring corn in Yanqing, with nearly 200,000 mu distributed in the dry land, can not irrigate and maintain natural corn production by natural rainfall. Therefore,