What is the model of Sangji fish pond?

Mulberry fish pond is an efficient artificial ecosystem created in the Pearl River Delta region of China, which is used to dig deep fish ponds, raise basal fields, plant mulberry trees in pond foundations and raise fish in ponds. Mulberry pond is a comprehensive way of planting mulberry in pond culture and ridge. The development of mulberry fish ponds not only promoted the development of mulberry planting, sericulture and fish farming, but also promoted the progress of silk reeling and other processing industries, and gradually developed into a complete and scientific artificial ecosystem.

The production mode of "Mulberry Fish Pond" is: feeding fish with silkworm excrement, fertilizing mulberry with pond mud, planting mulberry, raising silkworm and raising fish, forming a virtuous circle of interdependence and mutual promotion among mulberry, silkworm, fish and mud, avoiding waterlogging, creating an ideal ecological environment, receiving ideal economic benefits and reducing environmental pollution.

According to historical records, as early as the Han Dynasty, there were mulberry and silkworm rearing and silk weaving activities in the Pearl River Delta. At the beginning of the 7th century, merchants and foreigners from all over the Tang Dynasty came to Guangzhou to trade and sell silk. At that time, the Pearl River Delta was already a place where "rice fields ripened and silkworm fields harvested". However, the mulberry planted at that time was in the highland near Guangzhou, which had no connection with the fish pond and had not yet formed a mulberry fish pond. /kloc-At the beginning of the 20th century, during the Huizong period of the Northern Song Dynasty, the famous "Sangyuanwei" was built along the Xijiang River adjacent to Nanhai and Shunde counties, indicating that Nanhai and Shunde areas were already important areas for mulberry planting and sericulture. /kloc-At the beginning of the 5th century (1406), in the fourth year of Yongle in Ming Dynasty, local silk markets appeared in Longjiang and Longshan areas of Shunde, and silk production became a commodity. But no connection with fish farming was found.

Pond culture in the Pearl River Delta was first recorded in the Tang Dynasty in the 9th century A.D., with a history of mandarin fish culture. There are fry in the lower reaches of Xijiang River, which is an important condition for the development of fish in ponds. In the early Ming Dynasty, bighead carp, silver carp, bighead carp and shad have become common fish species in pond culture. The pond culture area has also gradually expanded, and gradually developed into pond culture District centered on Jiujiang in the South China Sea and Chencun in Shunde in the Pearl River Delta. But at that time, it was not found that the basal plane was used to plant mulberry and raise silkworm.

1522 (the first year of Mingjia), Quanzhou, Fujian and Ningbo, Zhejiang were closed by the Ming Dynasty, and Guangzhou became an important port for foreign trade of raw silk, which was exported to all parts of the world through Guangzhou. Subsequently, in 1553, Portugal invaded Macao, and foreign merchant ships entered one after another. Macao became a transshipment port for foreign trade, which promoted Guangdong raw silk to be better sold abroad.

At that time, the popularization of raw silk promoted the rapid development of sericulture. In Jiujiang and Nanhai counties, Longshan and Longjiang in Shunde county, and Poshan (Gulao area) in Gaohe county, sericulture has developed rapidly. There are many places where mulberries are planted in ponds, and the famous mulberry garden tail and ancient tail are in this area. Farmers in this area, after planting mulberry and raising silkworms for a long time, later found that silkworm excrement (silkworm excrement) can raise fish, and gradually realized that silkworm excrement is a good feed for fish in ponds. At that time, due to the need for more raw silk, more mulberry planting and sericulture, more silkworm excrement and more pond fish feed, the freshwater fish industry developed in large numbers at the same time. Farmers have gradually made it clear that there are more mulberry, silkworm, silkworm excrement and pond fish. As a result, Sangji fish pond, a special mode of production, gradually formed in the long-term production practice and soon spread to all parts of the Pearl River Delta.

1759 (twenty-four years of Qianlong), Manchu closed foreign trade ports such as Zhangzhou in Fujian, Dinghai in Zhejiang and Yuntai Mountain in Jiangsu, and Guangzhou became the only raw silk export port in China. Foreign businessmen gathered in Guangzhou to buy raw silk and silk products. Guangdong silk is sold to the outside world in large quantities, which requires a large increase in raw silk and silk products, thus promoting the development of sericulture and mulberry fish ponds in various parts of the Delta. It will soon form a vast mulberry garden fish pond area in Jiujiang Township, Nanhai County, Longshan Township, Longjiang Township and Poshan Township, Gaohe County (now Gulao) in the northwest of the Pearl River Delta. Among them, Jiujiang, Nanhai County as the center, abandoned fields to build ponds, abandoned rice and abandoned mulberry, which set off the first climax of the development of mulberry fish ponds in the Pearl River Delta.

After the Opium War, new reeling technology was gradually introduced. 1866 (five years of Tongzhi), Nanhai Chen Qiyuan introduced new reeling technology from abroad and established the first modern reeling factory in the Pearl River Delta in Hongcun, Nanhai County. Soon, the wind of new silk reeling industry gradually blew from Nanhai County to all parts of the Pearl River Delta. Shunde established Yihe Changji Silk Reeling Factory with 500-600 female workers in Beiliang, which is the beginning of the great development of silk reeling industry in Shunde County. Since then, the silk reeling industry in Shunde has gradually replaced Nanhai County, ranking first in the Pearl River Delta. Due to the rapid development of new silk reeling industry, the development of sericulture industry has been promoted. Once again, the wind of "abandoning fields to build ponds and planting mulberry with waste rice" was set off, and the area of mulberry fish ponds was expanded again, forming the second climax of mulberry fish pond development in the Pearl River Delta.

Sangji fish pond rose in17th century, and began to develop in the early 20th century. Especially after the First World War, because European countries were busy with post-war recovery, China's raw silk sold well in the international market, which promoted the abnormal development of local sericulture. At that time, there were mulberry fish ponds everywhere in the Pearl River Delta, and the area of mulberry fish ponds was estimated to be about 6.5438+0.2 million mu, reaching the highest level in history. This is the third climax of the development of Sangji fish pond in the Pearl River Delta.

At that time, the price of sericulture was very high, and the value of each ton of mulberry (100 kg, 50 kg) was equal to one ton of rice, while the output of mulberry per mu was seven or eight tons a year, worth about 20 tons (19 10 year). One income from sericulture can support three or four people.

When sericulture flourished, there was a "silk boat" in Rongqi Town, Shunde every day to transport raw silk out of Guangzhou and back to silver. Therefore, there is a saying that "a boat full of raw silk and a boat full of silver". From 1905 to 1906, the raw silk output in Guangdong is about 40 million yuan, accounting for 3/4 of Shunde County. At that time, there were 66 foreign exchange banks in Guangzhou, Foshan and Shunde, and 44 in Shunde county, accounting for 65% of the total. It can be seen that Shunde people were rich at that time.

Since Chen Qiyuan introduced the new silk reeling machine in 1866, silk factories have been added in various counties in the Pearl River Delta, reaching 147 in19/8, increasing a large number of raw silk exports every year. Shunde county accounts for more than half of the silk factories and silk carts in the Pearl River Delta. 1922 raw silk produced in Shunde accounts for 97% of the whole delta and 80% of raw silk exported by the whole province.

With the development of sericulture and silk reeling industry, silk factories, silk markets, mulberry markets, silkworm markets and cocoon stacks all over the delta are located in sericulture areas. Concentrated in counties with Shunde as the center. At that time, the main cocoon markets were: Shunde: Rongqi, Guizhou, Liu Le, Longjiang, Lecong, Chencun, Daliang and Ganzhu. South China Sea: Guanshan, Geely, Pingzhou and Jiujiang. Zhongshan: Castanopsis carlesii, an ancient town. Xinhui: North Street. Sanshui: Southwest. Dongguan: Shilong.

The main cocoon stacks are: Shunde: Guizhou 71; 25 rongqi; Liu Le12; 10 Chencun; 8 Daliang; Lecong 6; ② Longjiang; *** 134. South China Sea: Guanshan 5. Sanshui: Southwest 25.

During the period of 1929, economic crisis occurred in the capitalist countries of the world, industry and commerce were depressed, the market was stagnant, the sales of silk products dropped sharply, the price of raw silk plummeted, and foreign sales continued to decline. The foreign sales of raw silk in 1938 is only one fifth of that in 1922. The area of fish ponds dominated by mulberry trees has been greatly reduced and gradually replaced by fish ponds dominated by sugarcane. In the early days of liberation, Sangji fish pond still occupied a certain position. Since the rise of market economy, the area of Sangji fish pond has been gradually reduced due to relatively intensive labor, long production cycle and great risks, and the output value is not as high as that of commune and brigade enterprises. After 1995, the Sangji fish ponds in the Pearl River Delta basically disappeared, some developed to the periphery of the Delta, and some were changed into fruit bases, flower bases, sugarcane bases and fish ponds.

Main features:

1, mulberry planting is closely related to sericulture, fish culture and pig raising.

2. Plants and animals support each other to form a benign ecological cycle.

3. Rational layout of ponds and foundations, and combination of water and soil resources.

Sangji fish pond is a kind of agricultural production form with unique local characteristics in the Pearl River Delta of Guangdong Province. It is famous for its virtuous cycle of production. The Pearl River Delta is formed by the confluence of three rivers, east, west and north, and is located in the south of the Tropic of Cancer. With mild climate, abundant rainfall, long sunshine time and fertile soil all year round, it is an important base rich in sericulture, pond fish and sugarcane. The delta has dense inland river networks, convenient transportation and superior natural conditions.

Because the Pearl River Delta is low-lying, floods often occur, which seriously threaten people's lives and production activities. According to local characteristics, local people dig low-lying areas into ponds according to local conditions and raise freshwater fish in some low-lying areas; Pile soil around the fish pond to form the pond foundation, which can reduce the flood. Building the foundation of this pond can kill two birds with one stone.

Later, with the development of agricultural production and the influence of market economy, new production structure models-"fruit-based fish pond" and "mulberry-based fish pond" appeared in the Pearl River Delta. "Fruit-based fish pond" is to dig deep low-lying land into pond culture, pile soil to lay the foundation, fill the high terrain, and relatively lower the groundwater level to plant fruit trees (such as litchi, citrus, longan and other fruit trees). Later, due to the expansion of the demand for silk in international trade, the profit of planting mulberry and sericulture greatly exceeded the income of fruit, and many areas changed from the original fish pond production form dominated by fruit to the professional production of mulberry and pond. Fruit-oriented fish ponds have gradually evolved into mulberry-oriented fish ponds, where fish are raised in ponds and mulberry is planted in ponds, thus solving the problem of waterlogging in low-lying areas. People have changed the traditional farming methods and made full use of land space and rotation time to achieve the best economic benefits.

Jiantang

The specifications of the newly-opened Sangji fish pond require that the pool-base ratio be 1: 1. The pond should be rectangular, with a length of 60-80m or 80- 100m, a width of 30-40m and a depth of 2.5-3m, and a slope ratio of 1: 1.5. Dig the pond into a centipede-shaped group ditch, or a 6- 10 single-pond parallel channel fish pond, connect the foundation, and build a main water inlet and outlet canal and road (2-3 meters wide). This is conducive to regulating pond water, feeding, fishing, transporting and excavating pond sludge, as well as cultivating mulberry trees and picking leaves to raise silkworms. In the excavation season of Xintang, it is advisable to choose late autumn and early winter with low water and little rain. The dug new pond should be aired for a few days, then some organic fertilizer or fertilizer water should be applied, and then water should be released to raise fish. Strengthening the management of pond foundation The growth, leaf yield and leaf quality of mulberry trees in pond foundation directly affect the yield and quality of cocoon, silk and fish. Therefore, it is the key to improve the overall benefit of mulberry garden to cultivate and manage mulberry well and increase the yield of leaves. High-yield cultivation techniques in Tangji mulberry orchard should adhere to the cross measures of "improving soil and increasing fertilizer, improving seed quality, close planting and fine management" in order to achieve the goal of fast, high-quality and high-yield, and realize the benefits of mulberry planting and sericulture in the same year.

improve soil

Digging a fish pond makes the original fertile and loose topsoil and cultivated layer become subsoil, and the original subsoil is filled on the surface of the pond foundation. As a newly cultivated soil layer, although the organic matter content has increased, the reducing substances are also increasing. Therefore, before planting mulberry, all the soil on the pond foundation should be ploughed once, with the depth of 10 ~ 15 cm, so as to be weathered by freezing in winter, enhance soil permeability and improve soil water and fertilizer conservation capacity. After several years, the mulberry base was improved with the application of mud fertilizer mulberry in the pond year by year, and the base surface was continuously reduced, which affected the growth of mulberry. Therefore, the pond foundation should be improved for the second time. Dig low the high foundation, widen the narrow foundation and renovate the fish pond, so that the difference between the foundation surface and the highest water level in the pond is about 1 m, and replace the old mulberry.

fertile

It is necessary to master the principle of increasing farm organic fertilizer and intercropping green manure. First, mulberry should be planted with sufficient base fertilizer, with 30-40 kg of phosphate fertilizer100-200 tons, 0-20 tons of manure150-200 kg of cake fertilizer150-200 kg of lime per mu to improve acidic soil. Second, after mulberry trees survive and grow new roots, apply a quick-acting nitrogen fertilizer from late April to early May, with 20 kilograms of urea or 50 kilograms of ammonium bicarbonate per mu, preferably 50-80 tons of decomposed human excrement and urine. Apply it again in late July, and the amount of fertilizer should be appropriately increased compared with the last time to promote the growth of mulberry branches and leaves, so as to pick leaves and raise silkworms in Mid-Autumn or late autumn. Third, the growth and development stage of mulberry requires silkworm rearing and fertilization once. And pay attention to reasonable intercropping, a variety of leguminous green manure, and timely burial. Fourthly, a layer of silt was dug on the base in winter, which not only purified the fish pond, but also applied sufficient base fertilizer for the growth of mulberry trees on the base in the coming year.

improved variety

Excellent grafted mulberry varieties with high quality and high yield should be selected for planting mulberry in pond base, such as Hu Sang 197, Hu Sang 199 and 32, Lilium brownii 7920, etc. , also planted early and middle mulberry varieties about 15%.

plant closely

After artificial soil improvement, the soil layer is loose, so it is enough to dig shallow ditches to plant mulberry trees. Due to the high groundwater level in the pond foundation, the mulberry root system is shallow and suitable for close planting. When planting mulberry, it is better to plant it in fixed rows and close density, with row spacing of 33 cm× 132 cm or 50 cm× 1000 ~ 1300 plants per mu. Mulberry planting site should be 70 ~ 100 cm away from fish culture water surface, and the trunk of mulberry should be 20 ~ 30 cm high, so as to cultivate a low-middle-dry tree type.

ductus deferens

After planting mulberry in pond foundation, we must do a good job in cultivating mulberry, such as intertillage, weeding, fertilization, pest control and reasonable logging, to ensure high and stable yield and improve leaf quality in pond foundation mulberry garden.

According to statistics, in 1949, when the new China was founded, the national mulberry orchard area was only 198400 hectares, and the cocoon output was 30900 tons. After more than 20 years of tortuous development, China's sericulture industry reached 233,400 hectares, until 1.970, and the cocoon output reached 1.2 1.5 million tons, surpassing Japan for the first time, ranking first in the world. Since then, China has been listed as a big sericulture country in the world. Since the reform and opening up, the peak of sericulture development in China is around the 1990s at the end of last century. From 65438 to 0994, China's cocoon output reached 776,900 tons, and sericulture was developed in 26 provinces and cities. 195 The mulberry field area in China was1167,000 hectares, and the cocoon output still reached 759,800 tons. However, during the Tenth Five-Year Plan period, due to the adjustment of industrial structure in the eastern region of China and other factors, the sericulture industry in the main producing areas declined significantly, which led to the decline of China's proportion in the global cocoon production by about 2 percentage points year by year, weakening the leading position of China's sericulture industry in the world.

For a long time, the distribution pattern of sericulture production centers in China is closely related to natural climate conditions and socio-economic conditions. For a long time in the past, sericulture owners in China should focus on the eastern region with abundant labor resources, convenient transportation, fertile soil and prosperous economy. However, with the deepening and development of China's reform and opening up, great changes have taken place in the industrial structure of sericulture areas in the east, various industrial enterprises have developed rapidly, and the costs of land, labor and other factors in the east have risen, gradually losing the development advantages of traditional sericulture industry, leading to the shrinking of sericulture industry.

In order to stably and continuously develop sericulture in China and ensure the foreign exchange earning capacity of the national silk industry, it is considered that the western region of China has obvious advantages in the cost of production factors such as relatively rich land resources, sufficient labor force and relatively low prices. In this case, the westward migration of sericulture is an inevitable trend. To this end, the state has implemented the "moving mulberry from east to west" project in the "Eleventh Five-Year" development plan. That is, from 2006, the sericulture base project was started in the west of China 15 provinces (autonomous regions and municipalities). With the implementation of this project, it marks that the sericulture development center in China has started a strategic shift from the east to the west.

The essence of the project of "moving mulberry from east to west" is to move sericulture base and cocoon and silk primary processing center in China to the western region, rather than introducing sericulture to the western region for the first time.

The project of "moving mulberry from east to west" hopes to develop sericulture and protect the ecological environment in the west by vigorously developing mulberry planting, expanding vegetation coverage in the west and reducing soil erosion.

Due to the relative shortage of water resources, cultivated land in western China is not fertile and lacks organic matter. In addition, the terrain is high and the ability to be washed and transported by rain is strong. In such a fragile ecological environment, the development of sericulture industry, which consumes a lot of farmland fertility, is likely to cause serious ecological and environmental problems such as farmland degradation. Therefore, when developing mulberry planting in the west, it is particularly important and urgent to fully consider returning silkworm excrement to the field, apply more organic fertilizer, strictly control the amount of chemical fertilizer, and strengthen the protection of farmland fertility and water.

Therefore, the ecological protection of the "moving mulberry from east to west" project is the key to the sustainable development of the project. During the implementation of the "Moving Mulberry from East to West" project, relevant departments must adhere to the Scientific Outlook on Development, scientifically assess environmental risks, develop ecological sericulture to promote comprehensive industrial utilization, and apply ecological principles to solve environmental problems such as farmland degradation and water pollution that may be caused by the "Moving Mulberry from East to West", which not only achieves good economic and social benefits, but also ensures the sustainable development of the project with good ecological benefits.