The idea of "doing what you can" was put forward earlier. Fu Xuan (2 17-278) of the Jin Dynasty put forward: "Don't spend an extra acre, but cultivate its skills." In other words, it advocates increasing agricultural output, not by expanding cultivated land area, but by paying more attention to investing more labor in a certain unit area. Jia Sixie, a post-Wei agronomist, further put forward that "anyone who tills the fields must measure his strength". In other words, to manage the scale of agriculture, we need to measure our own strength, commensurate with material resources and labor. We can neither blindly expand the scale of operation beyond our own strength, nor shrink the scale of operation, so that our own strength can not be fully exerted.
"Give full play to strengths and avoid weaknesses" is also one of the traditional ideas of agricultural management in China. In Historical Records and Biography of Huo Zhi, "... there are thousands of fish in the water and thousands of chapters in the mountains. "AnQian Yi jujube tree; Yanqin thousand trees; Thousands of oranges in Shu, Han and Jiangling; Huaibei and Changshan are south, and there are thousands of trees between the river and the classics; Chen and Xia Qian mu painted; Qi and Lu thousand acres of mulberry horses; A thousand acres of bamboo in Weichuan ... "is a vivid portrayal of Han people developing various agricultural production according to local conditions, making full use of their strengths and avoiding weaknesses, and giving play to their regional advantages." According to the situation at that time, Tang Zhen in the Qing Dynasty made a true description of "Longyou herding sheep, Hebei sericulture, Huainan sericulture, lake reeling and Wuxiang people weaving mats". The viewpoint of giving full play to strengths and avoiding weaknesses has been passed down from generation to generation and has become an important part of agricultural management thought. "Pursuing advantages and avoiding disadvantages" is another important part of China's ancient agricultural management thought "The Biography of Huainanzi Miao Zi": "People's feelings seek small things in harm and great things in profit. The application of the thought of "seeking advantages and avoiding disadvantages" in agricultural production is a summary of Ma Yilong's experience of "planting grains to prepare for disasters" in Ming Dynasty, which not only clearly summarizes the principle of seeking advantages and avoiding disadvantages in agricultural production, but also "knows its suitability and does not abandon it; "Know what is right for you, avoid what you can't, and rise to the height of" infinite strength ". "
During the Qin and Han dynasties, the theory and technology of soil farming have been greatly improved. "Fan Sheng Zhi Book" puts forward the basic principle of farming: "The foundation of all farming lies in having fun, being in harmony with the soil, irrigating with manure, hoeing early and harvesting early." "Happy time" means to be timely and not violate the farming season. Based on the whole agricultural farming, this principle puts forward the comprehensive application of farming measures and other measures and the technical problems that should be paid attention to.
In terms of farming techniques, the book Fan Sheng Zhi summarizes the suitable farming periods of spring ploughing, Xia Geng ploughing and autumn ploughing: "When you plough at the right time, you will get the reward of time." On the other hand, the "preserved fields" and "preserved fields" that appeared in time are both cultivated fields. In this kind of field, the soil is hard and dry, and crops can't grow well. Secondly, it inherited and developed the farming experience of "adapting the soil according to the time" summarized in Lu Chunqiu during the Warring States Period. Thirdly, in order to win a bumper harvest in Guanzhong area under dry climate, Fan Sheng Zhi also summed up the farming experience of timely kneading to preserve moisture and prevent drought, and emphasized that the hard and solid black ridge soil should be "flattened" in time after ploughing. After ploughing, the loose soil must be "suppressed" and "dense forest". The Book of Fan Sheng Zhi also records: "If it rains and snows in winter, we should use [things] to urge it. Cover the snow and don't let it fly away with the wind. After the snow returns to the forest, beginning of spring will protect the ze and freeze to death with insects, which is suitable for crops in the coming year. " To sum up, during the Qin and Han Dynasties, China laid the initial foundation of the farming technology system for moisture conservation and drought prevention in the northern dry land.
Cao Wei regime paid attention to reforming production tools and popularizing new production technologies. The irrigation tools used in the Eastern Han Dynasty were overthrown, and they were more portable and applicable after the reform of Ma Jun.. The ploughing and sowing technology invented by Zhao in the Western Han Dynasty was brought to Dunhuang by Huang, the magistrate of Dunhuang, during the Cao period. In this way, the old farming methods in this area have been changed, more than half of the electricity has been saved, and the grain has increased by five points.
Niu Geng was widely popularized in Wei, Jin, Southern and Northern Dynasties. Niu Geng, China's iron plow, came into being in the late Spring and Autumn Period. Although it was popularized in Qin and Han dynasties, it was not really popularized. "Generally speaking, it has not entered the Niu Geng era" [1]. In Han Dynasty literature and stone reliefs, the main form of expression is two cows pulling the bar. There is a saying in later generations: "A cow on 30 acres of land, and the wife and children are hot on the kang." This is a portrayal of farmers' wishes, and it also shows us that only 30 mu of land can support 1 cow. Like one of the "three outstanding heroes of early han dynasty", his family can be said to be the representative of small farmers in the Qin and Han Dynasties, and it was only "thirty acres of land" [2] ("Chen's family"). Therefore, it is difficult for ordinary farmers to own plows, and Niu Geng in the Han Dynasty was only welcomed by the landlord class. In the later period of Liang Wudi, Zhao Guodong made great efforts to "teach people to learn from each other" [3] (Shihuozhi), which also proved from the opposite side that under the system of "two cows", Niu Geng, an ordinary farmer, was not widely implemented. After the Western Jin Dynasty, it was very common for a single cow to pull a plow. In the murals in the late Wei and Jin Dynasties, its number has exceeded two cows. [4] It is not difficult to see that the single cow model reduces the cost of a plow by almost half, so it is conducive to the promotion of Niu Geng; During the Wei, Jin, Southern and Northern Dynasties, nomadic people entered the mainland, which also increased the number of cattle. Most ordinary farmers can afford a cow (see the third part of this article for details). Only in this period did Niu Geng really become popular, and China's agriculture really entered the Niu Geng era. "Biography of Fu Xuan in the Book of Jin" said that Cao Wei plowed the field: "Those who hold official cattle get six points for the official, four points for the scholar, and those who hold private cattle are divided with the palace." This shows that it has been widely used in Niu Geng in the Central Plains. The former Yan Murong family settled refugees in the Liaohe River basin to develop agriculture, and also "according to the old law of Wei and Jin Dynasties" and "each gave a cow to the poor without assets" [5] ("Murong Lake Dang @ ① Record"). In the murals of Wei and Jin tombs excavated in Jiayuguan and other places in the second half of last century, there are a large number of Niu Geng pictures, including 7 in Tomb No.7, with an estimated total of more than 20. Most of its contents are folk farming and military reclamation. The cultivators include Han nationality, Xianbei, Qiang, Stone and other ethnic minorities. [6] This shows that in the Wei and Jin Dynasties, even in remote areas such as western Liaoning and Hexi, Niu Geng has been widely popularized with the mainland.
During the Wei, Jin, Southern and Northern Dynasties, the most important contribution of the northern people to agricultural production tools was the invention of the iron-toothed harrow drawn by animal power. The iron-toothed harrow is the "iron-toothed harrow @ ②" mentioned many times in Qi Yaomin's Book, and it is the earliest document record of animal-drawn harrow (for example, the article "Tilling the Field" said that millet was planted in the barren field @ ③: "After ploughing, use the iron-toothed harrow @ ②"). At present, the earliest animal harrow images we have seen are murals of Wei and Jin tombs in Jiayuguan and Jiuquan. The original animal-drawn harrows were all made of bars with single rows of harrow teeth, and people were very unstable when standing on them. For example, the rake portrait brick unearthed from Tomb No.6 of Cao Wei shows a woman squatting on the rake with a whip and rope, and there are many rake teeth under the rake. A strong ox is struggling to rake the rake in the driveway, and the woman's long hair is elegant, which makes the whole picture more lively. [6] There are about 10 pieces of harrow portrait bricks in Jiayuguan and Hexi areas. From this point of view, although the animal-drawn rake has just been invented, its popularity is still quite fast.
On the traction equipment, the rope soft sleeve was used in Wei and Jin Dynasties, and the rake may have appeared. It is generally believed in the academic circles that "the plow was not used at that time". It was not until the Tang Dynasty that Quyuan Plough began to use soft cover [7] (P246,318). However, in the brick portrait of the Wei and Jin tombs in Xigou, Jiuquan, Gansu [8](p54), there are two pictures of a single ox harrow, one of which is an ordinary single ox pulling a double-shaft single-row tooth harrow, and the other is very special: in the picture, a fat ox is harrowing the ground, and the traction equipment is not an ordinary long straight shaft, but two ropes, which are pulled tightly and straight, like two straight parallel lines. The operator behind the rake holds a reins in each hand to control the cow, the left hand is close together and the rope is slack; The right hand stretched forward and the rope tightened, as if directing the cow to turn right. The four ropes are very clear, and it is impossible to produce ambiguity. Therefore, the two ropes connecting the rake can only be soft sleeves for pulling farm tools. The farm tools used are two parallel cross bars, and for some reason, the rake teeth are not drawn below. However, judging from the development process of agricultural tools, there is only a rake in the future, and the rake also has the function of leveling the soil, so the agricultural tools can't be rakes, but rakes (also called "ox rake" in Brick Painting). The invention of soft cover makes farmland farming really flexible, fast and easy to operate; The frame harrow makes the harrow operation stable and safe, and the soil crushing effect is better. These two inventions have been used by later generations.
Before the Tang Dynasty, heavy long straight-axis plows were difficult to turn and cultivated land was laborious. In the long-term production practice, farmers have created a portable short-curved plow. Niu Geng on the murals of Li Shou's tomb during the Zhenguan period in Sanyuan, Shaanxi, and Niu Geng on the murals of Dunhuang in the late Tang Dynasty are all arc-shaped, which shows that Qu Yuan's plough is widely used in many places. According to Lu Guimeng's Lei Geng Jing in the late Tang Dynasty, Qu Yuan's plow was composed of 1 1, with three major improvements: 1. The long straight axis becomes a short curved axis. Today, the length of the old plow is about 9 feet, reaching the shoulder of the cow in front. Today, the length of Qu Yuan's plow is about 6 feet, only reaching the back of the cow. The plow frame becomes smaller and lighter, which is convenient to turn, flexible to operate and saves animal power. From the old-fashioned plow, two cows lift the bar to one cow for traction. 2. The plow evaluation was added. Because the thickness of plough evaluation decreases step by step, it promotes plough evaluation, makes plough arrow downward and plough deeply inserted into the ground; Pulling back the plow, making the plow arrow upward and the plow body shallow into the ground, can meet the different needs of deep tillage and shallow tillage. 3. The plow wall was improved, and it was round in the Tang Dynasty, so it was also called the plow mirror. You can push the turned soil aside, reduce the resistance to progress, turn the clods over and cut off the growth of grass roots. After its appearance, this kind of plow was gradually popularized and became the most advanced farming tool. The basic shaping of plows is a major improvement of plows by the working people in the Tang Dynasty. All kinds of waterwheels were widely used in farmland irrigation, which was an important factor in the development of agricultural production in Tang Dynasty.