明朝為防制蒙古部族秋天牧馬南下，自永樂五年（1407）起，命北邊國防線上的軍隊，每年例行性地出邊燒荒。以往學者認為：這一政策對草原的生態帶來極大影響，導致其土壤沙漠化。但據本文考察，邊軍執行燒荒並不切實，故其影響程度應該大打折扣。尤其是在隆慶四年（1570）以後，明帝國與蒙古達成和解，邊境對峙的局勢相對緩和，燒荒政策重新調整，長城沿線九鎮，除薊鎮、遼東持續執行未變外，宣府、大同、山西在萬曆九年（1581）以後不再實施。其他四鎮也曾短暫停止才又恢復。即使如此，敷衍了事的情況還是存在。值得注意的是，萬曆初年以後，燒荒的季節由草木枯黃的十月，改為綠草如茵的七月，焚燒的效果自然不如以往。晚明七十年間，燒荒已經徒有其名，對內蒙古草原生態環境的影響，應該不像以往學者所說的那般嚴重。

During the Ming Dynasty, starting in 1407, military forces guarding the northern border were ordered to routinely burn the grass on the Mongolian prairie beyond the border annually, in order to prevent Mongolian tribes from invading their southern countries in autumn. In the past, scholars believed that this policy had a tremendous impact on the ecology of the prairie, causing desertification of the soil. However, based on the observations from this study, the execution of the burning policy by the border army was not carried out precisely. Therefore, its impact was limited. Especially after 1570, reconciliation between the Ming Empire and Mongolia led to a relaxation of the border confrontation and a modified burning policy. Along the Great Wall’s nine defense sections, only Jizhen (薊鎮) and Liaodong (遼東) continued the policy. Xuanfu (宣府), Datong (大同), and Shanxi (山西) stopped carrying out the policy after 1581. As for the other four sections, it was restored after being discontinued for a short period. Even so, the policy was carried out perfunctorily. One noteworthy fact is that after 1570, the season for burning was moved from October (lunar calendar), when grass was withered, to July, when grass was lush. The effect of burning was obviously different than it had been before. After seventy years, at the end of the Ming Dynasty, the burning was only nominal. Therefore, its effect on the ecology of the Mongolian prairie probably was not as severe as scholars have tended to believe.