slash-and-burn cultivation(dāo gēng huǒ zhòng)

slash-and-burn cultivation

Slash and burn farming is a residual agricultural management mode in the Neolithic age. Also known as migration agriculture, for the original farming system. First with stone axe, and then with iron axe to cut down trees on the ground, such as withered roots and rotten stems, plants and trees dried and burned with fire. After the fire, the land becomes soft and does not turn over. The ground ash is used as fertilizer. After sowing, no fertilizer is applied. Generally, it is planted one year later.

historical origin

The agricultural management mode remained in the Neolithic age belongs to the primitive farming system. First with stone axe, and then with iron axe to cut down trees on the ground, such as withered roots and rotten stems, plants and trees dried and burned with fire. After the fire, the land becomes soft and does not turn over. The ground ash is used as fertilizer. After sowing, no fertilizer is applied. Generally, it is planted one year later. Due to extensive management, the yield per mu is only about 50 kg, commonly known as "planting a slope, harvesting a pineapple". The Yangshao cultural area in the middle reaches of the Yellow River used slash and burn cultivation and land rotation to cultivate millet and millet as early as 5000-3000 BC. Yunnan also used this method to grow rice as early as 1260-1100 BC in the late Neolithic period of Shang Dynasty. During the Warring States period, slash and burn farming was widely used in Yunnan Indigenous peoples. After the first century B.C., slash and burn farming was gradually reduced in central and Western Yunnan with the migration of land, but it was still retained in remote mountain areas. with the development of production tools from stone knives, stone chisels, stone axes and wooden sticks to iron knives, hoes and plows, the cultivation of crops has changed from single rice to rice, corn, beans, coarse cereals and even sugar cane and oil crops, and the cultivation mode has also changed from slash and burn cultivation, abandonment to rotation, multiple cropping and multiple cropping. Since 1978, slash and burn farming has been basically abolished in the border ethnic areas and remote mountainous areas due to the increase of agricultural investment, the construction of irrigation and water conservancy, the implementation of fixed cultivated land and the prohibition of deforestation and reclamation.

Operation mode

Slash and burn farming is also called migratory agriculture, which is called "guerrilla agriculture" in some places. It is an ancient and primitive farming method. There is no fixed farmland for this farming method. Farmers cut down all the trees on the ground first, and sometimes cut off a ring of bark of some big trees to let them die, and then cut them down. After the dead or air dried trees are burned, farmers clear out a piece of land in the forest, dig out small pits with digging sticks or hoes, put in a few seeds, and then bury them in the soil to obtain food by natural fertility. When the fertility of this piece of land declines, it will be abandoned and another piece of land will be developed, so it is called migration agriculture. At present, it is common in Africa. In the past, this kind of agriculture was widely distributed. Today, it can be seen only in the lowlands and hills of the tropical rain forests in South America, Africa and Southeast Asia. It is a type of farming carried out by some indigenous tribes. Some ethnic minorities in Hainan Island and Yunnan Province also adopt this kind of farming method. It vividly and vividly describes the characteristics of this mode of production, and also shows the backwardness and helplessness of agricultural activities. in Brazil, the Indians of the Amazon grow corn, cassava, beans and potatoes; the tribes living in the jungles of Southeast Asia grow yams and upland rice. The farming of migratory agriculture is extensive. The varieties of crops planted on a piece of land are different, the planting methods are disorderly, and there are no ridges or rows. The crops grow high or low, which seems to be a backward phenomenon. In fact, it is also an adaptation to the tropical rainforest environment. Tropical rain forest has heavy rainfall and dense raindrops. Mixed planting, crop height is uneven, high plants cover and protect the low and fragile plants below, and multi-layer plants prevent the tropical rainstorm from attacking and scouring crops and the ground layer by layer. On the other hand, a variety of crops are mixed, the ripening time is different, and the edible time is staggered, which avoids the difficulty of grain storage. But this kind of farming method is planted, without any management, let it grow naturally. Because no fertilizer is applied to the land, after two to three or three to four years, the nutrients of the land are not only absorbed by crops, washed by rain and decomposed rapidly by bacteria, so that the ash nutrient elements left by burning vegetation are completely consumed. Each piece of land can only be cultivated for 10-20 years, or even less. If the land around the farmers is abundant, they will wait for the vegetation to be basically restored before slash and burn cultivation; if the land is not abundant, they will have to speed up their replacement, and they will not wait for the vegetation to be restored before slash and burn cultivation. In this way, the ash nutrition left by the fire will gradually decrease, the years of maintaining growth will continue to shorten, and the replacement speed will be faster. Such a vicious circle eventually led to the destruction of ecological balance, so the farmers had to move to other places.

Adaptation mode

Another factor affecting the rate of replacement is the number of people. With the increase of population, the area of cultivated land needs to be expanded. Compared with other modes of agricultural production, slash and burn farming requires more land per person. Migration agriculture is a kind of self-sufficient natural agriculture, which can only meet people's minimum food needs, and there is no surplus products for exchange. In migratory agriculture, there are very few animals. The animals raised can only be eaten on religious festivals or other festivals, so people's nutritional composition lacks protein. Fishing and hunting can partly supplement the deficiency. although this mode of agricultural production is backward, it is the result of the adaptation of people living in this environment for a long time, and it is also the summary of long-term practice.

conventional wisdom

When it comes to slash and burn farming, a scene of ancient times will appear in many people's minds. A group of people are dressed in animal skins and clothes. They wave big knives and spears, cut down trees and set fire. Then they use a wood awl to pierce their eyes in the field and scatter seeds casually. They don't plough, fertilize or weed It is associated with such bad words as backwardness, barbarism, ignorance and low productivity. After the words of environmental protection and ecology entered the mainstream ideology, slash and burn cultivation was criticized as one of the factors that destroyed the environment. "On the one hand, slash and burn cultivation, on the other hand, green mountains are evergreen." It can be called a more progressive way.) Wa people in Ximeng, Nu people and Dulong People in Nujiang River Valley have been engaged in slash and burn farming for hundreds of years or even thousands of years. If this way of living can not live in harmony with nature, it will be eliminated by nature according to the theory of evolution! the most typical form of slash and burn cultivation is called "no rotation, rotation and rest type". A piece of land is only planted for one season and then abandoned for leisure, with a leisure period of about 10 years. This type of land is called "lazy land" by many ethnic groups, which means that you can get harvest without much effort, so it is the first choice of all ethnic groups. Only when the population increases and the land is not enough, will there be a "rotation type". Slash and burn farming is not aimless burning in the virgin forest, but has a long time of careful planning. Therefore, this kind of agricultural mode should be guaranteed by relevant social system. For example, they will take the village as a unit and divide the lazy work of the whole village into ten parts. Only in this way can they plant one part a year and reincarnate once a decade. Under normal circumstances, what is burned is not the virgin forest, but their "land". The mountain people cut down trees, burn wasteland, sow seeds and harvest in the mountains on duty. Each process has its own traditional rules. For example, the fire lane should be cleaned before the fire, and special personnel should be assigned to guard it, so as to avoid the mountain fire crossing the boundary. When you cut down trees, you should leave piles for big trees and roots for small trees, so that they can grow again in the spring breeze next year. There are many advantages to burning wasteland. The red soil in Yunnan is mostly acidic, and the plant ash is alkaline, which can improve the soil. The fire cooked grass seeds and insect eggs, so there was almost no need to control weeds and insects. The so-called "Dao Geng" is just a symbolic saying. If it is done, it will not benefit. Because deep ploughing will bury the plant ash and turn up the insect eggs and grass seeds deep in the soil. The timing of land burning is also specialized knowledge. Burning late will miss the farming time, burning early can not immediately sow, but let weeds get the opportunity. If a piece of land is cut and burned for only one year, it will be a pity to outsiders. The shorter the cultivation time is, the easier it is for the roots to regenerate, the easier it is for the vegetation to recover, and the less soil erosion is. Every year, the newly burned land is the lazy land that has been restored for nearly ten years, which can ensure that the soil fertility is always new. In this way, mountain people always have land for planting, mountain forests for hunting, forming a virtuous circle with nature, and farming is also knowledge. Many nationalities implement different interplanting schemes. There are not only hanging in the air (upland rice, beans, millet, etc.), but also climbing on the ground (Nangua, etc.), and underground drilling (yam, etc.), up to a dozen or even dozens of species, which can be fully utilized The sun and the land were destroyed. Therefore, it is also called "baibaodi". Mr. Yin pointed out that the comprehensive income of baibaodi is much higher than that of fixed cultivated land. At the same time, the working hours of baibaodi are half less than that of hoeing and ploughing in rotation, mainly in weeding and killing insects. Therefore, this mode of production is the result of the active choice of mountain people. Only in the case of insufficient arable land, we have to adopt the method of rotation tillage. In Mr. Yin's view, knife ploughing, hoeing and ploughing are not three different agricultural modes in different stages of development, but three agricultural modes in different occasions. The latter two are not more advanced than slash and burn cultivation, but are the result of the tense relationship between man and nature. many ethnic groups know that planting water wax gourd in lazy land is a fast-growing tree species with many fallen leaves and rhizobia that can fix nitrogen, which is conducive to enhancing soil fertility. The Wa people in Ximeng are planting tree species in grain harvesting, the Jingpo people in kachang of Yingjiang are planting tree seeds and upland rice seeds at the same time, and the Dulong and Nu people in Nujiang are planting seedlings. This rich diversity shows that slash and burn cultivation is not due to ignorance, but rather a deep "knowledge" of the nature in which it lives.

Chinese PinYin : dāo gēng huǒ zhòng