玉米是我社的主要粮食作物,常年播种面积约占作物种植面积的40％以上,1972年以前,玉米亩产都是徘徊在200斤左右。为什么这样低呢?我们调查分析的结果,主要是一劣、二浅、三迟、四稀、五瘦所造成的。劣,就是种子不纯不良,都是本地的老品种;浅,就是土地没有深翻,耕层浅; Maize is the main food crop of our society. The perennial planting area accounts for more than 40% of the crop planting area. Before 1972, the mu yield of maize all hovered around 200 kilos. Why is it so low? The results of our investigation and analysis are mainly caused by one inferior, two shallow, three late, four thin, five thin. Bad, that is, impure impure, are all local varieties; shallow, that is, no deep plowing the land, shallow farming;