One of the earliest drought-resistant farming methods may be planting mu. Mu, which is the furrow and ridge that can be seen in the field today. One of the reasons why the ancients plowed the fields and ridged the ridges was to fight drought. In ancient times, there was a saying that "abandoning acres in fields", which meant that planting seeds in ditches instead of ridges in high fields would be beneficial to drought resistance and moisture conservation. In fact, the reason is relatively simple. The cause of drought is water shortage, especially soil water shortage. As the saying goes, water flows downwards. When the ditch is lower than the ridge, the water content of natural soil is higher than that of the ridge. This is the principle of drought resistance by bathing.
The method of planting mu was mainly implemented before the pre-Qin period, and the method of substituting farmland appeared on the basis of the method of planting mu in the Western Han Dynasty. Substituting farmland is a farming method invented and popularized by agronomist Zhao Guo in the middle of Western Han Dynasty. Its method is to open three furrows (beds) with a width of one foot and a depth of one foot on a strip of land of one acre. The positions of the furrows rotate every year, so it is called "Dai Tian". Sow the seeds in the ditch, and when the seedlings sprout and grow leaves, cultivate and weed at the same time, and bury the ridge soil on both sides of the ditch in the roots of crops to play the role of wind resistance, lodging resistance and drought resistance.
The method of substituting farmland is developed from the method of planting mu, and its basic structure is also composed of mu and species, that is, ridges and furrows. Technically, it has the following characteristics: First, furrows and ridges alternate with each other. Sow in the ditch, and after emergence, ridging (leveling) the ridged soil by combining intertillage and weeding. Its function is to prevent wind, lodging and drought, which actually embodies the principle of "removing fields and abandoning acres" in the method of planting acres. The second is the exchange of furrows and ridges. The positions of ridges and ditches rotate year by year, and this year's ridges will become ditches next year; This year's ditch will become a ridge next year. Because fields are always planted in ditches, ridges and ditches are exchanged, and land use and leisure are realized in turn. The third is the combination of ploughing and ploughing. In the field substitution method, soil preparation, ditching and ridging are required every year. After emergence, the ridge should be leveled by intertillage weeding, and the soil on the ridge should be backfilled into the ridge ditch to achieve the effects of drought resistance, moisture retention and lodging resistance. Due to these characteristics of the land substitution method, coupled with a series of supporting agricultural tools, such as carts and combined plows, the land substitution method has indeed achieved good results and the total output per unit area has been improved. Compared with the flat farmland without farmland replacement, the yield per mu is often more than one ton, and even doubled when it is good. It has really achieved the good effect of "Gu Duo gets twice the result with half the effort".
In Han dynasty, there was another drought-resistant and high-yield cultivation technique and method, that is, regional planting method. Area planting method, also known as area field method, is specially designed for drought resistance. There are two forms of planting, one is wide planting and the other is small planting. Whether it is a wide field or a small field, it has the following characteristics: (1) plowing the land outside the plot, and fully tapping the potential of increasing production of the land inside the plot. (2) equidistant sowing, the row spacing and plant spacing of crops in the field have certain specifications, and the form of equidistant sowing is adopted to ensure good ventilation and light transmission conditions of crops. (3) It is easy to manage. Because the field is not cultivated next to the field, fertilization, irrigation and intertillage weeding are all carried out in the area, which is convenient to give full play to the role of manpower and material resources and facilitate the operation in the area. (4) Because the field is not cultivated on the side, it only focuses on deep ploughing in the area, which plays the role of anti-corrosion and soil conservation. This feature makes "Zhushanling, near-city Gaoxian, Sakamoto and Qiu Cheng all regional fields", which not only increases the yield per unit area, but also expands the cultivated land area.
However, whether it is planting mu method, field substitution method, planting area method, ridge cultivation method or flat cultivation method, we all have to face problems such as how to reduce soil water loss, how to level the land after tillage, and how to break clods. In the Han dynasty, the method of combining tillage and kneading was adopted, that is, the land was leveled after ploughing and the clods were crushed by kneading to reduce the loss of soil moisture. During the Wei and Jin Dynasties, a "rake" was added between tillage and kneading, forming a trinity of tillage, rake and tillage technology system for dryland farming. From then on, the dry farming technology in northern China was formed.
Although there are relatively developed water conservancy undertakings in the history of China, they have lagged behind the development of agriculture for a long time. Coupled with natural reasons, drought has become the biggest unfavorable factor for China's agricultural development. Drought is the biggest natural disaster in the history of China. The dry land in northern China is also the main drought-prone area. To solve the drought problem, the first thing is to build water conservancy projects. In the case of lagging water conservancy projects, drought-resistant farming is a more effective method. Drought-resistant farming technology is one of the reasons for the sustainable development of China agriculture and even Chinese civilization for thousands of years.