前言玉米是北京郊区主要粮食作物之一,常年播种面积在300万亩左右,约占粮食耕地面积的60%。八十年代以来,玉米的单产和总产均有较大幅度的提高。单产由七十年代的400多斤的水平提高到600多斤,总产由12亿斤左右跃至17亿斤上下。京郊玉米的种植方式主要有三种:一是春播,主要在山区的旱地,面积约60万亩;二是小麦玉米二茬套种,面积约180万亩; Foreword Corn is one of the major grain crops on the outskirts of Beijing. Its perennial planting area is about 3 million mu, accounting for about 60% of the total area of ​​cultivated land. Since the 1980s, the yield and gross output of corn have increased substantially. The yield increased from over 400 kilos in the 1970s to more than 600 kilos, and the total output jumped from about 1.2 billion jin to about 1.7 billion jin. Suburban corn cultivation There are three main ways: First, sowing, mainly in the dry land in the mountains, an area of ​​about 600000 acres; second crop of wheat and corn, an area of ​​about 1800000 acres;