《天工开物·上篇·乃粒》
比方说，有牛的农户能耕种十亩农田，而没牛的农户用铁锄，勤快些也能种上前者田数的一半，既然是没有牛，在秋收之后，也就不必考虑在田里种牛饲料及放牧的麻烦事儿，同时可以腾出手来种植豆、麦、麻、蔬菜等作物了。
假如有牛者，供办十亩。无牛用锄而勤者半之。既已无牛，则秋获之后，田中无复刍牧之患，而菽麦麻蔬诸种，纷纷可种，以再获偿半荒之亩，似亦相当也。
For example, a farming household with oxen can cultivate ten acres of farmland, while a farming household without oxen can also cultivate half the number of acres of land with a hoe if they are hard-working; and since they do not have oxen to tend to, they would not need to bother cultivating fodder or grazing pastures after the autumn harvest and would have more time to grow beans, wheat, flax and vegetables.