国外的旱地农业耕作技术（上）高焕文中国农业大学机械工程学院西方国家在大规模开垦１００～２００年、机械化作业几十年后，发现耕地先后出现两个大问题影响着农业的持续发展。一是土壤侵蚀退化，土层变浅变瘦，产量下降，严重的农田被毁，无法耕种；二是土壤压实，物理... Agricultural Technology in Dryland Abroad GAO Huanwen School of Mechanical Engineering, China Agricultural University After decades of large-scale reclamation and westernization in mechanized operation, Western countries discovered that two major problems of cultivated land occurred in succession that affected the sustainable development of agriculture. First, the degradation of soil erosion, shallow soil thinning, production decline, serious farmland destroyed, unable to cultivate; Second, soil compaction, physical ...