我国北方属于干旱或半干旱地区,秦、汉以后,历代虽有一点水利建设,但随着封建王朝的兴衰,时立时废,有水利灌溉设施的农田面积,占比重很小,农业生产主要是“靠天吃饭”。农民和自然斗争的长期实践,逐步形成了传统的旱农体制,不论作物布局、土壤耕作、栽培管理,都密切结合当地条件,充分利用自然降水,以获得最好产量,这是一条重要原则。这条原则在我国北方很早就确立了。北魏贾思勰著《齐民要 Although northern China belongs to the arid or semi-arid areas, Qin and Han dynasties have a little water conservancy construction. However, with the rise and fall of the feudal dynasty, the farmland area with irrigated irrigation facilities occupied a very small proportion and agricultural production was mainly “Rely on the weather to eat.” The long-standing practice of peasants and nature has led to the formation of a traditional system of dry farming. It is an important principle that crop production, soil cultivation and cultivation and management all closely follow local conditions and make full use of natural precipitation to achieve the best yield. This principle was established very early in our country’s north. Northern Wei Jia Si with "Qi Min want