Chapter 9 Section 2 Intensive land use

Land utilization is the basis of agricultural technology. Expanding the area of ​​agricultural land and increasing the yield per unit area of ​​agricultural land (ie, land productivity) are two ways to develop agricultural production.With the increase of population, China has been expanding the area of ​​arable land and the scope of agricultural land in successive dynasties, but when each agricultural management unit considers its production policy, it always focuses on increasing the output per unit area.At least it has been like this since the Warring States Period.In the early years of the Warring States period, Li Kui [kui Kui] was Minister of Wei, and he promulgated the decree of "doing the best of the soil", pointing out whether to be diligent or not diligent in governing the land, and to increase or decrease the yield by three measures per mu, and within a hundred miles, 6 million mu of land can be cultivated Within the period, the total grain output increased or decreased by 1.8 million shi, or 20%. "Making the best of the ground", in today's words, means increasing land productivity.Xunzi also believes that if the land is cultivated well, it can produce "several pots" per mu (a pot is a measuring device, one stone is two buckets and eight liters), which is equivalent to harvesting twice a year, with great potential.

In order to increase the total output by increasing the unit yield, we cannot blindly expand the scale of operation.Agronomists of all dynasties have advocated intensive management, planting less and harvesting more.For example, Jia Sixie believes that "mortals must measure their own efforts in farming, and it is better to have less good than too much evil" ("Qi Min Yao Shu").Chen Yan advocated that "more empty is worse than little real, wide planting is worse than narrow harvest" ("Nong Shu"), and proposed that the scale of farming should be "commensurate with financial resources".The "Shen's Agricultural Book" of the Ming Dynasty also advocated that "it is better to be few and precise, not too many and sloppy."The emergence of this idea is not simply due to the increase in population, the shortage of arable land and the weak economic strength of small farmers.People have realized in the long-term production practice that intensive management and less planting and more harvest are more economical in the use of natural resources and human and financial resources than extensive management and extensive planting and low harvest. "Shen's Agricultural Book" takes the management of mulberry land as an example, pointing out that if the thin tubes are cultivated deeply and more fertilizers are applied, "one mu and two mu can be used, while labor, money, grain, and land are still only one mu."He also quoted the words of an old farmer: "Three dans are also fields, two dans are also fields, and five tans are also fields. It is better to plant more than less, which saves effort and field."

The agricultural yield per unit area in ancient my country was much higher than that in ancient Western Europe and the Middle Ages.The ratio of grain harvested to sown in Western Europe is four to five times as recorded in the Roman Book of Cromera, and three times as recorded in the 13th-century British Book of Henry.According to "Qi Min Yao Shu", the harvest volume of millet in my country in the 6th century was 24-200 times of the sowing volume, and that of wheat was 44-200 times.According to the "Bu Nong Shu", the highest rice yield in the Jiahu area in the late Ming and early Qing Dynasties reached 415 shi, which is 901-1126 jin per mu today, which is higher than the rice yield in California today.The land productivity of ancient Chinese agriculture undoubtedly reached the highest level in ancient society.

Land productivity is closely related to .Under the guidance of the idea of ​​"doing the best of the soil", the land utilization rate in ancient my country has been continuously improved, which is mainly reflected in the development of the farming system centered on the planting system.In the primitive agricultural period, our country changed from the raw wasteland farming system to the cooked wasteland farming system very early. In the traditional agricultural period, it changed from the leisure system to the continuous cropping system as early as the Warring States period.In Western Europe, until the end of the 18th century, the three-field system of regular rotation of leisure was still maintained.On the basis of the continuous planting system, the working people in ancient my country made many outstanding creations.

One is crop rotation.If one crop is continuously planted in a field, it will often lead to the lack of certain nutrients and the growth of some diseases, insect pests and even weeds. Reasonable stubble replacement can adjust and strengthen the soil fertility, and reduce the harm of diseases, insect pests and weeds.The ancient crop rotation in my country is characterized by the widespread use of bean crops or green manure crops with fertilizing effects and cereal crops in rotation, and the methods are flexible and diverse. The second is intercropping.Intercropping is the planting of two or more crops in rows or strips on the same land.Interplanting means that the next crop is sown between rows before the previous crop is harvested, and the interplanted crop continues to grow after the previous crop is harvested.Doing so makes the best use of arable land and crop growing seasons.It requires a reasonable mix of tall and short stalks, sun-loving and shade-loving, deep roots and shallow roots, and various crops with different growth periods and fertilizer requirements, so that they do not interfere with each other, and even promote each other.The "Book of Fansheng" in the Han Dynasty has introduced the method of planting scallions [xiexie], that is, scallions [jiaojiao] heads or small beans in the middle of the melons, and harvesting the scallions or bean leaves before the melons mature and selling them. In "Qi Min Yao Shu", there are records of planting turnips, mung beans, and adzuki beans in mulberry fields, planting turnips among pockmarked seeds, and planting millet among soybeans.Chen Yan's "Nongshu" summarizes and recommends the way of intercropping ramie in mulberry fields.In the Ming Dynasty, new experiences such as rice interplanting and wheat-cotton interplanting appeared, and in the Qing Dynasty intercropping methods became more colorful.

The third is multi-ripe planting.As early as the Warring States Period, Qin and Han Dynasties in the Central Plains of my country, the multiple cropping system had sprouted (such as planting grains and beans after winter wheat was harvested), and double-cropping rice was planted no later than the Han Dynasty in parts of Lingnan.But these are sporadic and scattered.The greater development of the multiple cropping system was in the Song Dynasty, when the people in the Jiangnan area, where the economic center was located, planted wheat, beans, and rapeseed after the rice harvest.In the Ming and Qing Dynasties, the multi-cropping system of rice and wheat in the south of the Yangtze River was further developed.The planting of double-cropping rice in the south is more extensive and has expanded to the Yangtze River Basin. In some areas, the three-cropping system of two rice and one wheat in a year has appeared.In many places in North China, the two-year three-cropping system with wheat as the center appeared as early as the Tang and Song Dynasties, and it tended to be finalized in the Ming and Qing Dynasties. The typical form is to plant winter wheat after the autumn harvest, plant beans after the wheat, and plant beans after the next year. Corn, millet, millet [jiji], etc., after harvest, winter wheat is still planted, and the cycle is repeated sequentially.Yang Qi's "Xiu Qi Zhi Zhi" also recorded the experience of two years and thirteen harvests of grain and vegetables intercropping.

Agriculture relies on green plants absorbing sunlight and converting it into organic matter.The characteristic of my country's traditional farming system is the combination of multi-cropping planting, crop rotation and intercropping, and intercropping. On the one hand, it maximizes the coverage area of ​​green plants, so that "planting has no idle land"; As a result, "planting without empty days" makes full use of soil power and solar energy to increase the output per unit area.This farming system places high demands on water, fertilizer and tillage management, and must be very familiar with the characteristics of various crops.

Intercropping and crop rotation are already a multi-species, multi-level three-dimensional layout. This method of making full use of land can also be extended from large fields to water bodies, and from planting to multiple operations.For example, in the Han Dynasty, a comprehensive land use mode appeared in which ponds were used to irrigate rice, fish and lotuses were raised in ponds, and trees were planted on embankments. Archaeologists have discovered many paddy field models of ponds in Han Dynasty that reflect this situation.Chen Yan's "Nongshu" summarized the experience of digging ponds in Gaotian to store water for rice planting and planting mulberry cattle on embankments.During the Ming and Qing dynasties, some low-lying areas (mainly the lower reaches of the Yangtze River and the Pearl River Delta) adopted the embankment production method more widely: digging ponds in low-lying areas, piling up soil as embankments (or "bases"), raising fish in the ponds, and raising fish on the embankments. Plant mulberry (or plant fruit, sugarcane and other crops), mulberry leaves feed silkworms, silkworm arrows (feces) feed fish, pond mud blocks mulberry, recycling.For example, there are mulberry-based fish ponds, fruit-based fish ponds, cane-based fish ponds, and rice-based fish ponds in the Pearl River Delta.In some places, livestock and poultry production and field production have also been added.For example, during the Jiajing period of the Ming Dynasty, Tan Xiao brothers developed barren depressions in Changshu, Jiangsu. The deepest depressions were dug into fish ponds, and aquatic plants such as water chestnuts [ci words] (water chestnuts), water chestnuts, water chestnuts, and gorgons were planted in the second depressions, and vegetable beds were grown if conditions permit; Chickens and pigs are raised in cages on the pool, and fish are fed with their manure. High walls are built around the fields, and plums, peaches and other fruits are planted on them.According to the "Buying Book" and other records, in the late Ming and early Qing dynasties, the Jiahu area of ​​Zhejiang Province formed a combination of "agriculture-mulberry-fish-livestock" production mode: fish were raised outside the fair, mulberry was planted on the fair, rice was grown inside the fair, and Mulberry leaves are used to feed sheep, sheep dung to block mulberry, or the by-products or waste of field crops are used to feed livestock and poultry, livestock and poultry manure is used as fertilizer or fish, and pond mud is fertilized to grow grains.These production methods skillfully utilize the mutual support relationship between land and water resources and various agricultural organisms, form a reasonable food chain and energy flow, form an artificial ecosystem with high production capacity and economic benefits, and raise the land utilization rate to a new level. the height of.

At present, in the exploration of Chinese-style agricultural modernization, combining traditional experience with modern technology, there is an upsurge of research and promotion of various three-dimensional agricultural models all over the country.The main feature of three-dimensional agriculture is the coexistence of multiple organisms and multi-level configuration to improve resource utilization, land output and product commodity rates.The embryonic form of this three-dimensional agriculture appeared in the Ming and Qing Dynasties. It heralds a direction of agricultural development and has far-reaching significance.

The main direction of Chinese traditional agriculture is to improve land utilization and land productivity, and this is the basis of the intensive farming technology system.Intensive land use and intensive farming are mutually exclusive.

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