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一、演变与现状种植制度的演变不但受生态因素的影响,而且在很大程度上决定于社会需求、经济基础和科学技术的发展。江苏省棉麦连作两熟正是沿循这一规律而演变的。早在50年代中期,就出现了大、元麦收后直播棉花的田块。因受生产条件和科学技术水平的限制,这一种植方式棉花产量低而
I. Evolution and Status The evolution of cropping system is not only affected by ecological factors, but also largely determined by social needs, economic foundation and development of science and technology. Cotton and wheat in Jiangsu Province even as a double crop is evolved along this rule. As early as the mid-50s, appeared on the field, Yuanmai direct broadcast cotton field. Due to production conditions and the limitations of science and technology, the cotton yield is low