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介绍了美国的玉米生产概况及玉米的区域化和专业化生产、杂种优势利用、培肥地力、增加种植密度及实现机械化作业等高产栽培措施
Introduced the general situation of corn production in the United States and its high-yielding cultivation measures such as regionalization and specialized production of maize, utilization of heterosis, fertilization of fertility, increase of planting density and mechanization operation