From breadth development to in-depth development – the sustainable development of traditional Chinese agriculture

【Guangming Academic Writing】

Author: Han Maoli (Professor, Center for Paleogeography and Ancient Literature, Peking University, Distinguished Professor of Boya)

China is a large agricultural country with a long history, but also one of the world's earliest domestication of crops, long-term agricultural practice not only explored a set of intensive farming agricultural production technology, but also promoted the development of Chinese civilization through sustainable agriculture. Although the ancients did not put forward the concept of systematic sustainable development, they ran its essence throughout in practice. The sustainable development of China's agriculture benefits from the theory of heaven, earth and people advocated by the ancients, which is dominated by people to reasonably coordinate the relationship between heaven, earth, water and soil and crops, ensuring the sustained and stable development of agriculture, of which the key technical support lies in the following three aspects.

According to the time of day, favorable geographical conditions, and the form of land use according to local conditions

Soil is the supplier of crop nutrients and water, supply and consumption, and the reciprocating cycle in agricultural production, so that ancient Chinese farmers not only mastered the technology of identifying soil, but also committed to fertilization, fertilizer, and use of land according to local conditions.

Identifying soil is the premise of using soil and transforming soil, the ancients identified soil from two aspects, and the identification is based on the whole country, focusing on the macro scale to understand soil traits. The earliest dialectic comes from the "YuGong" written in the early Warring States period, which divides the world into Kyushu, and according to the state of Yinong, the soil of Kyushu is divided into nine grades. Soil focuses on each piece of farmland where crops are grown. There are many expositions about the material soil of the pre-Qin Zhuzi, among which the Xunzi Wangzhi says: "Phase high and low, see fat [~ symbol ~], the five kinds of preamble ... The matter of ruling the field also. "The core of the soil lies in arranging crops according to local conditions and determining the correspondence with crops according to soil characteristics."

From choosing to use soil to improving soil. In the early days of China, agriculture belonged to the rotational farming system, people divided the land into several pieces, the soil fertility was naturally restored by taking turns to save the land, and the crops were constantly replacing the land in the desertion-tillage cycle. About after the spring and autumn the land entered continuous use, artificial soil fertility appeared. Agricultural books such as the Zhou Li, the Book of Victory, and the Qi Min Zhi Shu record that the initial way to replenish soil fertility was to seed manure rather than dung, that is, to wrap manure juice on seeds. The fertilizer efficiency of manure seeds is only in the seed germination stage, for the full growth period of crops, followed by manure fields, which is commonly referred to as fertilization.

The premise of fertilization is fertilization, and the Song Dynasty Chen Xu's "Agricultural Book" mentions that livestock manure and "burning ash, dusty chaff, broken leaves", river mud can be superior. And "wherever the farmhouse is flanked by dung houses, low eaves to protect them from the wind and rain, and manure dew stars and moons are not fat." The dung house is chiseled into a deep pond, and the bricks are made to prevent leakage. Whoever sweeps away the soil, burns the ashes, raises the chaff, breaks the fallen leaves, accumulates and burns, and accumulates with dung juice." In the Song Dynasty, the economic center of gravity of ancient China has shifted to the area around the Taihu Plain in the south of the Jiangsu Province, which has also become a model area for intensive cultivation, and the Song people Qin Guan once had such an exclamation: "Today, the fields under the sun are said to be like Wu, Yue, Fujian, and Shu, and their one acre is several times that of other states. Pi Wu, Yue, Min, Shu, ancient Yangzhou, Liang Prefecture land also. According to the "Yugong" Yangzhou Tian Ninth, Liangzhou Tian Seventh, is the field of the two states in the Kyushu, etc. the lowest, and now the wo yan is called He Zhao? Wu, Yue, Fujian, and Shu are narrowly populated, and the contribution of cultivating dung irrigation is also the same. After the accumulation of fertilizer, how to fertilize is equally important, Chen Xu's "Agricultural Book" said: "Depending on the nature of its soil, it is appropriate to dung and dung, and it is reasonable to be reasonable, slang is called fecal medicine, and it is also used with feces to use it." "The use of manure pays attention to the rational fertilization of time, place and crop.

Land use adapted to local conditions. Soil is only the foothold of crops, and each seed of crops carries geographical information, so the choice of water and soil not only began at the beginning of agriculture, but also ran through the entire development process. Each side of the water and soil has its own crops, and the establishment of the corresponding relationship between crops and water and soil is to adapt to local conditions. Such measures have existed as early as the agricultural activities in the Spring and Autumn Period, and since then they have been promoted to future generations and spread throughout the country.

Intensive farming techniques for agricultural production

Intensive farming system is to support the sustainable development of traditional Chinese agriculture to achieve the basis, fertilization is only one of the links, seed selection, breeding, farming, land preparation, sowing, cultivation and weeding, irrigation, harvesting, the main content of contemporary farming, the ancients have long been incorporated into practice, and successfully achieved sustainable development of agriculture. The pre-Qin document "Lü's Spring and Autumn" raises a series of questions, including almost all aspects of agricultural production, reflecting the practices that farmers have already thought about and are doing during this period.

Since the "Spring and Autumn of the Lü Dynasty", the Western Han Dynasty's "Book of Victory" and the Northern Wei "Qi Min Zhi Shu" have presented all aspects of farming to people one by one, of which "farming" is the core of traditional agronomy, accompanied by a series of operations such as harrowing land, raking land, paddy field rake land and fertilization, which will create a foothold for crops as a top priority. If we summarize the intensive cultivation of Chinese agriculture, most of it is used on the soil, the other half is used on crops, and it is completed through weeding, fielding, fertilizer and irrigation, and the labor is not only "noon on the day of hoeing", but also runs through each agricultural time.

Agricultural planting system from breadth development to deep development

Breadth development is land expansion, and depth development is multi-species with wheel as the core. The rotation of crops practiced in ancient Chinese agriculture includes: the purpose of increasing the number of harvests, the implementation of a one-year ripening system for the same piece of land, and the rotation of crops for the purpose of maintaining the performance of the land.

There are two types of crop rotation, one is to rotate crops for the purpose of maintaining the performance of the land. A piece of land grows the same crop for many years, absorbing the same nutrients, and the soil will be impoverished as a result. Each crop has a corresponding pest and disease, and a piece of land growing a crop for many years is equivalent to providing stable growth conditions for a certain pest and disease. Crop rotation can effectively alleviate these problems, such as cereal crops absorb more nitrogen and potassium, while calcium absorption is less, legume crops are just the opposite, the implementation of these two crop rotation can successfully balance soil nutrients. The "Qi Min Zhi Shu" pointed out: "In the field of all valleys, mung beans and small bean bottoms are the top, hemp, millet and flax are secondary, and turnips and soybeans are the bottom." "According to the demand for soil nutrients from cereal crops and legumes, the rotation of these two types of crops constitutes nutrient complementarity. The second is to rotate crops for the purpose of increasing the number of harvests. Agricultural production provides food and clothing for people's livelihood, and the population continues to multiply under the nourishment of agriculture. To meet the food needs of the multi-breeding population, expanding the land is one way, as is improving land utilization and implementing the multi-ripening system of crops.

When rotation requires knowing the heavens, the land, and the peasants, the knowledge of the heavens, the earth, and the peasants comes from the labor of the peasants, and the implementation of rotation is taken from the needs of the people. The two-year three-cropping system with winter wheat as the core was implemented in the area of present-day Shandong as early as the Spring and Autumn Period and the Warring States Period, and gradually prevailed in North China. Compared with the two-year three-cropping system in the north, the southern part implements a two-year rice and wheat rotation, which matured in the Song Dynasty. Rice is originally a product of the water village environment, and the implementation of rice and wheat rotation is to implant dryland crops in paddy fields, which is very rare even in the world's major rice-planting areas today. With a two-crop rotation a year, Gangnam not only harvested two crops, feeding more people, but also took a big step forward in agricultural technology.

Since the Qin and Han Dynasties, the Yangtze River Basin has been implementing the "fire cultivation and water transfer" system of easy land, and the land utilization rate is up to 50%. After the "Anshi Rebellion", the northerners went all the way south, and the population pressure pushed the land utilization rate in Jiangnan from 50% to 100%. After the continuous cultivation of the land, the replanting technology of "pulling and planting" prevailing in the northern rice fields was adopted, and on this basis, the seedling planting technology was formed. Rice occupies the land from May to August and winter wheat from September to May, and the two crops of rice and wheat fill each other's gaps in time and space, creating conditions for changing the form of land use and crop rotation in the southern plains. The double-cropping of rice and wheat in one year not only increased the land utilization rate in Jiangnan from 100% to 200%, but also doubled the yield of crops. The Taihu Plain, supported by the rotation of rice and wheat crops twice a year, has a wealth that surpasses other regions, which promotes the southward shift of the economic center of gravity in ancient China.

Population history research tells us that for more than 2,000 years, the Chinese mouths ranged from 20 million, 50 million to 80 million, 100 million, to 400 million in the Qing Jiaqing period, and behind the population reproduction were the products provided by agricultural production. This climbing population figure is a testament to the success of China's agriculture and agricultural technology. In the thousands of years before industrial society, agriculture became the basis for all social development.

Guangming Daily (2022-09-13 11 edition)

Source: Guangming Network - Guangming Daily