《后汉书·杜笃传》载杜笃《论都赋》,其中谈及以关中为中心的雍州之生产情况时,有“厥土之膏,亩价一金,田田相如,镭钁株林,功浅得深”等语。《中国经济史辞典》谓“火耕流种”即晋陆云《答车茂安书》中所说的“火耕水种”。此说欠妥。陆云的原文是:“遏长川以为陂,燔茂草以为田。火耕水种,不烦人力。决泄任意,高下在心。”说的是当时鄮县 “Post Du Han Du Du Fu” contains Du Du “on the Fu”, which talked about Guanzhong as the center of Yongzhou production, there is “the soil of the cream, a price of gold, Tian Tian Xiangru, radium Zhu Lin, Gong Shallow depth ”and other languages. “Dictionary of Chinese economic history,” that “fire farming species” that is, Jin Luyun “answer Carolinean book,” said “fire farming water species.” This is not good. Lu Yun’s original is: "Contain Changchuan thought 陂, burial grass that Tian. Fire water species, annoying manpower.