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3.1 Introduction

This section highlights some findings of the Mission regarding land and water management as it relates to aquaculture.

All over China Chairman Mao's statements, “Irrigation is the lifeblood of agriculture” and “Take grain as the key link and ensure all-round development of agriculture, industry, animal husbandry, forestry, sideline occupations and fisheries”, are frequently quoted.

It was the Mission's impression that these are not mere slogans as, in fact, the Chinese make great efforts to ensure the availability of controlled and timely water supply for agriculture and fisheries.

Mission members found that in the rural areas, crop production, animal husbandry and fish culture are effectively integrated. The basis for such close linkage is assured water supply as a result of water development projects and rural electrification.

The Mission also noted that water conservancy projects - completed or still under construction, such as storage reservoirs, embankments, irrigation and drainage canals or ditches - take fully into account the use of water bodies for aquaculture. Clearly, aquaculture is an integral part of agriculture.

Perhaps the most striking feature is the fact that such integration is practised at the farm level by farmers who are the beneficiaries of water projects.

In China, land and water are used with high intensity to ensure all-round development of rural life through increased agricultural production that includes fisheries. This is by far one of the most significant findings of the Mission.

The Mission found that China's technology is not unique or new. Most of its approaches have been or are being used outside China. It was clear to the Mission, however, that China is one of the few countries putting these relatively simple techniques into practice on a massive scale at the farm level.

There are, at the moment, a number of countries engaged in land and water resources development for crop production and fish culture. Chinese experience indicates the extent to which aquaculture can form an integral component of agriculture. Thus, the close relation between crop production and fish culture, which both require controlled and timely water supply, should be kept in mind when planning, designing and implementing land and water development schemes.

3.2 Water and its uses

Water is an essential input for agriculture and fisheries. A nation's water resources depend, basically, upon climatic and rainfall conditions and then on watershed conditions. Estimates of the annual water flow for China's major rivers are presented in Table 1 and of precipitation and runoff in Table 2.

These tables indicate that the average runoff from the major rivers in the north is markedly less than in the south. Given its more abundant water resources, the south is able to carry rice cultivation and fish culture at more intensive levels.

The estimated water use pattern in the Yellow and Yangtse Rivers is shown in Table 3.

Table 1
Discharge of the Major Rivers of China
(From: van der Leeden, 1975)

River(A) Annual flow
(m3 per year)
(B) Drainage area
(m3/km2 per year)
Hai     15 × 1090.26 × 106  58 × 103
Yellow     48 × 1090.75 × 106  64 × 103
Hwai     42 × 1090.26 × 106162 × 103
Yangtse1 020 × 1091.8   × 106567 × 103
Pearl    356 × 1090.42 × 106848 × 103
 1 551 × 1093.4   × 106456 × 103

Table 2
China - Precipitation and Runoff in Major River Basins
(From: van der Leeden, 1975)

River systemBasin area km2Mean annual precipitation mmMean annual runoff mmMean annual evaporation mmRunoff coefficient %
Sungari  523 580   512   14137127.6
Liao  219 000   465     7430115.9
Yellow (Hwang Ho)  745 100   415      6535015.7
Upper Yellow (Lanchow)  216 190   427   14827935.0
Fen (Hochin)    38 650   471     5032111.0
Lo (Chuangt' oul)    62 700   436     28408  6.5
Ching (Chiangchia Shan)    41 800   462     4741610.1
Wei (Hu Hsien)    63 550   573   14243125.0
Hwai  164 560   840   19864223.6
Yangtse1 808 5001 050   56848254.1
Chinsha  502 050   662   32933350.0
Min  133 5701 100   72237865.6
Chialing  159 810   892   40848446.0
Wu    88 2201 135   58654952.0
Tungting  261 1301 445   85259359.0
Han  174 350   900   35654440.0
Poyang  158 6801 670   97169958.2
Ch'ient'ang    49 9301 650   94071057.0
Min    60 8001 7101 07463662.8
Han    29 7001 655   98267359.0
Pearl (Si Kiang)  437 2301 480   89059060.2
Tung    26 3001 7581 20355568.4
Pel    45 6001 8851 37051573.0
Si (Wuchow)  328 0001 370   77060356.0
Upper Si (Nanning)    74 3101 340   64669448.0
Total Nation9 597 000   650   28037043.1

Table 3
China - Water Use in Yellow and Yangtse River Basins
(Source: Tojin Sha, 1964)

(Unit: 100 million m3)

Water useYellow RiverYangtse RiverTotal
Non-productive1  22.4   15.0  37.4
Industrial and urban  12.8   12.8
Navigation  13.9    7.0  20.9
Fishing  11.8   11.8
Total293.9260   553.9

1 Non-productive water uses include:
(a) 740 million m3 of Tung-ping Lake water losses
(b) 1 000 million m3 of water losses from the Yellow River
(c) 500 million m3 of water losses from irrigation in all the provinces
(d) 1 500 million m3 of water losses from diverting the courses of the Han, Chi and Yellow Rivers.

According to this table water used for fisheries constitutes about 5 percent of irrigation water. In view of the fact that fish do not consume water, fish culture in irrigation ponds and canals is also encouraged and may point the way for others interested in the better use of water resources.

3.3 Land and water development strategy

3.3.1 Major schemes

The Mission was informed that China gives top priority to water conservancy in its various development programmes. Massive investment in both funds and labour has been directed to this end.

Chinese officials say there is much to do in this field. In the case of Hupei Province, only 30 percent of the total water programmes have been completed. Yet there is no doubt as to the tangible benefits this policy has gained. For example, there have been no serious floods on the Yellow or other major rivers during the past ten years.

It was stressed by Chinese officials that the stabilization of river flow and lake water and the formation of new water bodies have created an environment that favours agriculture production, particularly fish culture. Farmers can now direct their efforts to crop production and fish culture without fear of floods and drought.

The hydropower generated has increased power supplies in rural sectors. The Mission was impressed by the fact that this had spurred mechanized operation of farming and fish culture, particularly water pumping, with the widespread use of electric pumps.

The Mission was informed that the basic bench marks on government policy and action in water control and development may be broken down as follows:

1950–55Elimination of major flood damage through rehabilitation and construction of dikes and increase in the flow capacity of rivers by river draining work.
1955–60Storage of water, extension of irrigated areas, particularly in the north.
1960–65Increasing irrigation efficiency and productivity of irrigated areas by installing water regulating structures in completed projects. Improving irrigation system management, paying particular attention to the combined development of irrigation and drainage, and hydropower generation.
1965-Continued and increased emphasis on comprehensive development covering flood control, irrigation, drainage, hydropower and navigation; intensification of land and water use, including on-farm watering systems and land consolidation.

As a result of these policies China completed an estimated 130 000 km of dikes and an irrigation network covering 28 000 000 ha of land between 1950 and 1973. The total irrigated area is estimated now at 44 000 000 ha.

3.3.2 Hupei Province (as an example)

Through discussions with Hupei Provincial Government officials the Mission noted that:

1949–53Emphasis was placed on flood control through the reconstruction of river dikes, particularly on those of the Yangtse and Hai Rivers. In total, about 7 000 km of dikes, including 1 200 km along the Yangtse and 900 km along the Hai, were reconstructed.
1954–58Irrigation development was a major objective and included the construction of reservoirs and irrigation canal systems; 5 000–6 000 dams were constructed covering about 30 percent of the total provincial catchment area.
After 1959Multipurpose water development, including flood control, irrigation, navigation, hydropower generation and fisheries, has taken place.
Overall achievement:The reconstructed and newly constructed river dikes cover about 8 000 km. More than 7 000 dams, including 32 big ones, have been constructed. As a result, flood damage has been greatly reduced while the production of hydroelectric power has been substantially increased. Irrigation development covering an area of about 700 000 ha contributes to yield increases; compared with yield levels in 1949 the present grain yield is 2.7 times higher and the cotton yield is eight times higher.
Development criteria:Flood control aims at preventing flood damage which might occur at the frequency of once in a hundred years while drainage pumps are designed to cope with a maximum rainfall expected once in ten years or once in 20 years. As far as the spillway of dams is concerned, it is often the case to design for a thousand-year rainfall.
Irrigation works:Gravity irrigation is predominant in hilly areas and pump water supply is extensively carried out in the plains. Small reservoirs coupled with ponds are major sources of water supply in mountain areas. At present irrigation systems are designed to cope with drought which might occur for a period of 50 to 100 days.
Fisheries:The promotion of fisheries is always considered in reservoirs and intensive fish culture is always encouraged in small ponds. Fish culture receives due attention in drainage canals but not in irrigation canals. Details are discussed in the following sections.

3.3.3 Integration of major, small-scale and on-farm schemes

The Mission noted that the major water control programmes discussed in the previous chapter play a key role in stabilizing and increasing crop and fish production, and appreciated the part being carried out by small-scale water conservancy projects implemented by the people's communes, production brigades and teams. During its stay in the country, the Mission observed numerous small water conservancy projects, such as small reservoirs, ponds, pumping stations and canals. It was indeed impressive to see a series of small reservoirs and ponds linked together by irrigation networks in the hilly areas of Honan Province. From the sky they looked like a string of pumpkins hanging from a long vine.

It was noted that China's policy on water conservancy is to execute major, minor and on-farm works simultaneously to ensure integrated benefits from the various projects. The State concentrates its investment on key projects, while encouraging the people's communes and their subdivisions to put up small and on-farm projects, mobilizing the people, so that the water made available from major projects is immediately utilized for crop and fish production.

In the deltaic area of the Yangtse and Pearl Rivers, the Mission observed that a number of small pumping stations, including portable ones, are constructed by the communes. Linked with state-run, large pumping stations and hydraulic structures, they form extensive irrigation and drainage systems contributing to rice and fish production.

It is too often the case in other countries that major irrigation systems are kept idle for years after their completion, simply because of the lack of on-farm water distribution systems and of integrated operation of irrigation systems as a whole.

The Mission was extremely impressed by the integration of key projects with small-scale (on-farm) watering systems built and operated by farmers. The Mission believes that this is an area for further study and that FAO member countries would benefit by learning this method from China and putting it into practice in their own countries.

3.4 Reservoirs and ponds

Like countries all over the world, China builds its dams, reservoirs and ponds primarily to regulate runoff or river flow and to store water for agricultural, industrial and urban water use. But the water surface thus created is used by China for fish culture at a high level of intensity.

The Mission had the opportunity to observe various types of dams at the Agricultural Exhibition in Shanghai. From the engineering viewpoint, the design and construction methods adopted in China seem to be similar to those practised elsewhere. A great number of dams, particularly small-scale ones and ponds, are of the fill-type and are constructed mobilizing local labour.

From the fisheries viewpoint, the bottom grading and clearing is noteworthy. The Mission noted that in most reservoirs built before 1958, when speedy construction was needed for flood control and water storage, the bottoms were rarely cleared before water storage began. For the sake of smooth fish harvesting, however, the bottoms of small reservoirs recently constructed are not only cleared but stumps are removed. In some reservoirs, the bottoms are even graded. The subject is discussed further in the following chapter.

Over 280 large-scale reservoirs (storage more than 108 m3), 1 800 medium-scale reservoirs (storage 107–108 m3), and countless small-scale reservoirs (storage 105–107 m3) and ponds (storage less than 105 m3) were built in China. Of these more than 250 large, 1 300 medium and 11 000 small reservoirs (formed by dams higher than 15 m) were constructed after the Liberation.

From the fisheries viewpoint, the smaller the water area and the shallower the depth the higher the productivity is per unit area. Since medium and large-scale reservoirs are often constructed in remote places, small reservoirs and ponds provide better opportunities for fish culture. In particular, farm ponds closely located to villages and cultivated land are most suited to fish culture.

Chinese farmers seem to be well acquainted with the principles of gravity irrigation, and they have accumulated considerable experience in the construction and use of small ponds.

The Mission observed with interest the integrated management of the series of reservoirs and ponds interlinked by connecting canals. For example, water released from big reservoirs is directed to small reservoirs and ponds to ensure the water storage necessary for irrigation and fish culture. The Mission was informed that when water bodies are used for fish culture, a minimum water depth is maintained, say 3 m in summer and 1.8 m in winter.

In addition to reservoirs and ponds for water storage purposes, the special function of check dams merits attention.

One of the popular methods for preventing or minimizing soil erosion in hilly areas is to build a check dam. This is partly to store water. But the main purpose is to reclaim new farm land in river beds by precipitating and settling nutrient-rich silt behind the dams. Check dams are planned and constructed subsequently in a single small drainage basin. In general, 8–14 small fill dams (say 6–10 m high) per km2 are installed. Small reservoirs or ponds are thereafter created. They can be used for fish culture as they are located very close to farm land reclaimed and easily accessible to farmers.

3.5 Natural lakes

The vast Chinese landscape is dotted with lakes, not only in the warm, humid eastern plains but also in the cold high regions in the west. Some 130 lakes have more than 100 km2 of water area. These are mainly located in the middle and lower reaches of the Yangtse River.

Lakes in the southeastern part of the country are mostly fresh water. They are connected to major river systems. They play a very important role in promoting irrigation, navigation and fisheries.

The Mission was informed that lake waters were not regulated in the past. Unsystematic utilization of lakes and watershed areas often resulted in devastating flood and drought damage.

Regulation and control of these lakes became a major concern after 1949. The Government laid down lake water regulations and launched control work that aimed at:

  1. stabilizing lake water level for promoting agriculture, fisheries, navigation and recreation; and

  2. improving the regulating function of lakes against heavy rainfall in watershed areas as an integral part of comprehensive watershed management.

For this purpose a number of hydraulic structures, including pumps, are installed along the lakes and in the watershed area. Examples of such water-control works can be seen at Taihu Lake in southern Kiangsu Province, which the Mission visited on 7 May 1976. It has an area of 2 250 km2 with a shore line of 393 km.

Taihu Lake was originally part of a shallow sea. Encroachment by sand bars in the Yangtse and along the coast enclosed it to form the present-day lake, with water flowing into the Yangtse through 42 outlets.

In the past, control of the water courses in the Taihu Lake region received some attention as they were utilized for transport. But from the Opium War of 1840 to 1949 conditions deteriorated, as the lake water area was reduced to a wide expanse of paddy fields through the construction of dikes. This sharply reduced the water storage capacity of the lake.

Furthermore, poor management of rivers and streams connecting the lake to the Yangtse River cut their drainage capacities, due mainly to siltation. As a result, the area along the lake often suffered flood damage.

After 1949, 18 reservoirs were constructed. Hydraulic structures were installed in about 300 small lakes in the watershed area to regulate the runoff to Taihu Lake.

Parallel to watershed management works, outlets to the Yangtse River were improved through the dredging of the river bottom, embankment, installation of sluice gates and drainage pumps. Numerous pumping stations were constructed for water supply to farm land and fish ponds.

The Mission was informed that this comprehensive approach toward the lake regulation has resulted in stabilized water levels (±1 m). Together with an integrated management of lakes, reservoirs, canals and water structures this ensures rational utilization of land and water resources in the region for agriculture, fisheries, navigation and recreation.

The Mission was not in a position to obtain information and data on the water management systems of the lake and its watershed area. It seems that the integrated and systematic operation of the numerous hydraulic facilities installed is quite a complicated one. However, a detailed study on the subject merits attention.

3.6 Canals and creeks

The Mission understood that in the low-lying plain where the slope of irrigation canals is quite flat, flow velocity is comparatively low - say 0.1–0.3 m/sec - and fish culture is practised without artificial feeding.

In these low-lying areas rice is the major irrigated crop and canals and creeks usually function for both irrigation and drainage purposes. They are often also used for navigation. Water usually exists throughout the year providing good conditions for fish culture. Since such canals receive residuals from nearby farmlands and townships, water is usually fertile containing a considerable amount of plankton. A regular supply of fry and fingerlings is obtained through intensive fish culture to stock these waters.

Canals are often connected to main rivers or lakes with gate facilities that sometimes have pumps. The mechanism and operation of these water facilities firstly aim at controlling the water table in the canals and creeks to provide adequate water regime for irrigation and drainage. Due consideration is, however, given to fish culture as well as to navigation. Within the water course irrigation is mostly carried out with pumps which have no serious effect on fish culture provided that fish barriers are installed around the pump suction. The Mission was informed that fish barriers in canals and creeks, however, often cause navigation problems so that quickly movable barriers or barriers with a boat passage are being used.

On the other hand, the Mission was told that irrigation supply channels on the farms are generally not used for fish culture. The members of the Mission consider that this is understandable as the water discharge fluctuates from time to time in accordance with the change in water requirement. Such channels are often dried out for maintenance work. Furthermore, they are usually designed to minimize their cross-sectional areas with the velocity as high as possible for economy. As a result, it is often the case that:

In order to keep the hydraulic capacity of canals and creeks at the desired level, regular maintenance work is carried out, which includes the excavation of the bottom and weed cutting. The Mission observed that often the weed cut and the mud excavated are returned to the cultivated land as organic fertilizer. The effectiveness of grass-eating fish (e.g., grass carp) to clean water weeds in canals and creeks was mentioned but no technical details of this practice in China were available to the Mission. In view of the interest shown by some member countries of FAO in the subject, it merits further study.

3.7 On-farm water supply system

In areas where fish ponds and cultivated land coexist, on-farm irrigation systems are often used for supplying water to fish ponds. This is particularly noticeable in lowlying areas where water supply depends mostly on pumps. Water is lifted and led to the ditches which are connected to both farmland and fish ponds. It is the usual practice for paddy fields to be irrigated continuously while water is supplied to fish ponds when the water level falls below a certain limit (say 50 cm from the full water level). A concentrated water supply is needed when refilling the ponds after drainage, which is usually carried out in the winter when repairing ponds. While no detailed information was given to the Mission, it is assumed that the water supply is well scheduled so as to minimize power requirements.

Concrete or masonry lining is the most popular but precast concrete flume is also sometimes used. In areas where the land is valuable an underground pipeline system is used. The pipeline is buried under the farm road so as not to occupy the cultivated land. An example of this was observed by the Mission in the Chen-tung People's Commune near Shanghai. The Mission members felt that such a pipeline system contributes to increasing irrigation efficiency through the reduction of percolation loss during water distribution. It is felt, however, that the introduction of heavy machinery for mechanized farming may necessitate the use of stronger pipes and may require more earth covering of the pipes buried.

3.8 Fish ponds

The Mission observed a number of fish ponds constructed and managed by communes and governmental agencies. Physical conditions vary according to location and details on their management for fish culture are discussed under section 5.4.

Design criteria given below are extracted from “Fresh Water Fish Culture”, prepared by the Chanquan Aquaculture Research Institute and published in Chinese by Nongguo Publishing Company in 1974.

Water source

The availability of abundant and assured water of good quality at low cost is a basic need for planning and designing fish ponds. It is desirable, therefore, to construct ponds along rivers, lakes or canals with guaranteed water supply.

While efforts will be made to obtain water intake and drainage by gravity, the provision of water-lifting devices is necessary to cope with the fluctuation of outer water levels.

Water surface

A large water surface area is desirable. The larger the water surface the greater the effect of wind, which increases dissolved oxygen and promotes the mixing of upper and lower water layers; 0.7 ha (10 mu) is commonly used.

Water depth

Chinese experience shows that the most desirable depth of ponds is 2–3 m. It has been found that below 3–4 m there is not enough photosynthetic activity to keep the deeper water oxygenated, and the water temperature is low and contains less plankton.

Other conditions

As far as possible, high and dense forests and buildings should be avoided around ponds so as not to intercept solar radiation and wind.

It is desirable that the length of ponds should be east-west line in order to benefit from longer sunshine hours.

Dimensions and shape

A rectangular shape with 2:1 or 3:2 ratio is recommended.

The embankment crest width should be decided taking into account its usage but 1.5–2.0 m is usually adopted (for the passage of vehicles a much wider crest, say 2.5–3.5 m, is needed).

The embankment slope should be decided taking into account the soil stability but a ratio of 1:1.5 is usually adopted.

The pond bottom is practically horizontal. In cases where the water inlet and outlet are situated in different places, a 1/200–1/300 slope from the inlet side to the outlet side may be needed.


As far as possible, permeable soils are avoided. If, however, ponds are constructed on permeable soil, infiltration control should be practised, e.g., soil compaction, lining with clay soil, lime, plastic film and asphalt.


It is economical and convenient to install ponds in waterlogged areas or marginal land. Full consideration should be given to the effect of floods and to the convenience of transportation.

Ratio of various ponds

An example of the design of Tungshan fish breeding farm, Kiangsu Province, is given below:

Pond useArea (mu)Water depth (m)Water area ratio
Water storage3–5   3–4 
Adult fish4–10 3–47
Fingerlings3–5   2–3.52
Fry1–3   1.5–21

3.9 Paddy fields

The Mission was informed that the extent of fish culture in paddy fields is not as significant as in lakes or fish ponds; some farmers raise fish in paddy fields during the rice-growing period and during the off-season. The Mission could not obtain information on the subject through discussions. The information given here is extracted from literature cited in section 3.8.

Chinese experience of fish culture in paddy fields has demonstrated that:

3.9.1 Modification of paddy fields for fish

Paddy fields should have high and stable ridges. They should be 35–45 cm higher than the normal ones with a width of about 30 cm. The ridges should be well compacted to prevent the escape of fish and water leakage.

It is also often the practice to dig a part of the paddy field to maintain proper water depth for fish retention. Such fish ditches should have a water depth of 60–90 cm. The ditch area varies between 1–2 percent of the paddy area.

Paddy fields used for fish culture are those with assured irrigation water supply and effective drainage. Inlets and outlets are guarded with screens or nets to prevent fish escape.

3.9.2 Fish culture with rice cultivation

Fingerlings are put into paddy fields about a week after rice transplantation, and are kept there until after the harvest. Stocking density varies from 3 000–9 000 fish/ha (200–600/mu) depending on the fertility of paddy soils. Without feeding, fingerlings of 9–12 cm (carps and tilapia) at a density of 3 000–4 500 fish/ha (200–300/mu) are often put into the field.

There are cases, however, where fish are fed intensively. In Kwangtung Province, for example, a brigade cultivates 2.7 ha (40 mu) of paddy field for rice and fish. It harvests about 4 000 kg/ha (530 jin/mu) from the first crop of rice, 5 250 kg/ha (700 jin/mu) of rice from the second crop and 937.5 kg/ha (125 jin/mu) of fish as well.

The brigade also uses 0.4 ha (6 mu) of paddy field for intensive fish culture with a daily addition of 175 kg (350 jin) of pig/cow manure as fertilizer and 200 kg (400 jin) of green grass as feed. The harvest of rice and fish appears to have been excellent.

3.9.3 Water and farm inputs management

In the case of rice-cum-fish culture, it is mentioned that very careful management is required to watch watering, to avoid fish escape, and to prevent intrusion of ducks and carnivorous fish. Also, it is required to ensure the required water depth in the field and to prevent raising water temperature to above 31°C. It is said that irrigating with colder water achieves this end.

In so far as fertilizer application is concerned, it is said that the application of chemical fertilizer should be limited to 30 kg/ha (2 kg/mu) per day. Application of insecticide is handled carefully to avoid harmful effects on fish. Where heavy doses of insecticide are unavoidable, fish are collected before its application and are put back in the field after the insecticide toxicity comes within allowable limits.

In many instances, the shallower the water depth the higher the rice crop yield and the less the water requirement. Very often paddy fields require intermittent drainage, particularly at the late tillering stage to avoid harmful consequences due to the reduction of organic substances promoted under prolonged waterlogged conditions. Shallow water and intermittent drainage make fish culture in paddy fields difficult, if not impossible.

One possible solution that could be used is to enlarge the area and depth of fish ditches, although this may result in less cropped area. Furthermore, the practice of flowing irrigation to control water temperature often results in low irrigation efficiency. In promoting fish culture in paddy fields, these points should not be overlooked.

3.10 Water lifting devices

The Mission observed a number of large-scale pumps. For example, at the Pai-Tan Pumping Station in Hupei Province there were four sets of axial flow pumps with a capacity of 8 m3/sec/pump at 8 m per head. On the occasion of visiting the Agricultural Fair in Shanghai, the Mission learned that very large-scale pumps are installed in many water conservancy projects.

The Mission was under the impression that the country is capable of manufacturing and installing all kinds of pumps now being used elsewhere. The Mission thought that small pumps were manufactured locally and that they are widely used by farmers for on-farm and fish-pond water supply.

Most fish culture in China today is carried out in low-lying delta plains. Here the water level of canals and creeks is often below the surrounding land level. Thus, water lifting becomes indispensable for both irrigation and supply to the ponds. Water lifting devices are also needed when the ponds are drained.

Traditional water-lifting devices, such as the dragon wheel, were occasionally observed by the Mission, but electric pumps are now used extensively. On the occasion of visiting the Chen-tung People's Commune near Shanghai, the Mission was informed that the water supply in the area was done using animal-driven water-lifting devices with about 400 animals. These devices were replaced by 21 electric pumps in 1958; however, the Commune still keeps old devices as well as cattle for an eventual energy crisis. During discussion with Commune officials, the Mission was under the impression that the Commune gives special attention to the proper maintenance of pumps. The Mission was told that all 21 pumps were in good working condition and that spare parts were readily available. It should be noted that electricity is available in every rural sector and is one of the key factors contributing to the rapid development of pump irrigation and fish culture. Movable low-lift pumps are most commonly used. The lift varies from 1–3 m with an estimated discharge of 2–4 m3/min. Very often such a small pump is put on a boat and transported to the watering point. The pump is either operated by electric power available on the spot or by a diesel engine (usually 10 hp) used for the boat.

3.11 Land consolidation

The Mission was informed that the prime objective in land consolidation, including land grading, is to increase land and labour productivity. The work consists of land grading and reshaping (in most cases a rectangular shape) and provision of irrigation and drainage networks as well as farm roads.

In main fish areas, such as the delta of the Pearl River in Kwangtung Province, ponds occupy a considerable portion of the land, from 30 to 60 percent. Land consolidation, therefore, includes ponds or the water area. In the Le Liu People's Commune in Shun-ta County, for example, 50 percent of the land area is taken up by fish ponds, but the land and water (fish pond) areas were consolidated. As a result the number of irregularly shaped and scattered fish ponds had been sharply reduced and regularly shaped fish ponds in rectangular blocks of 60 × 90 m had been constructed instead. Overall, the number of ponds were reduced from 9 743 to 4 877, but the total area of fish ponds remained the same.

Land between the fish ponds, used for cultivation, had also been made more regular, and an irrigation network was installed at the same time. This was an impressive display of integration.

Such land-cum-fish pond consolidation, coupled with water control works, clearly increase land, water and labour productivity since farming and fishing operations in regularly shaped plots are more efficient. A timely water supply and application is also assured. Equally important, efficient transportation of farm inputs and commodities through networks of farm roads and water courses is provided.

The techniques used in China are largely identical to those used in other countries. But what is so outstanding is the massive mobilization of labour for earthwork.

Obviously one major reason for China's ability to implement speedy and large-scale land consolidation is the ownership system. Since land and fish ponds are state or commune owned, decisions on reshaping and reallocating land and ponds do not run into legal snags as in most other countries.

3.12 Fishways

The Mission was informed that hydraulic structures built across rivers, such as weirs and headworks, are usually provided with fish ladders so as not to impede the migration of fish. Fish paths are also built within gate structures. The Mission noted that as far as major schemes are concerned, the Water Conservancy Department is responsible for the design and installation of such facilities in consultation with fisheries agencies. Mission members were told of the experience in the Hwai River to illustrate the importance of the provision of this facility. An estuary barrage was constructed there in 1956 and 1957 to control flood and seawater intrusion in the deltaic area of the Hwai River and to store fresh water. After completion of the work, migration of crab and mullet was impeded. Production inevitably dropped. In 1965 the Tung-kou Fishery Commune harvested only 100–150 kg (200–300 jin) of crab per day and 50 kg (100 jin) of mullet per boat - a big drop from the 3 000–4 000 kg (6 000–8 000 jin) of crab per day and 1 250 kg (2 500 jin) of mullet per boat recorded in 1955.

A special task force for fishways design was formed in 1965. It examined the location, structure, capacity, velocity and water depth of the fishway together with the operation of sluice gates.

A fishway was constructed in 1966, which restored smooth migration of fry. Furthermore the operation of sluice gates was improved. These resulted in increasing crab and fish catches. More than 15 000 kg (30 000 jin) of crabs per day were harvested in 1972.

The Mission was not able to get technical information on the construction. The Mission considers that a coordinated approach toward the design and location of fishways built in hydraulic structures is often overlooked in FAO member countries and that a detailed study of experience in China merits attention.

3.13 Summary and recommendations

3.13.1 Summary

China places the greatest emphasis on comprehensive and intensive use of land and water resources for agriculture and fisheries. People at all levels met by the Mission pointed out that assured and controlled water supply and timely drainage are the key to successful agriculture and fisheries activities.

One of the major contributing factors is the availability of electric power in every rural area.

Most striking was the fact that techniques for effective and intensive use of land and water resources are practised at the farm level by farmers. The techniques are not very sophisticated, but they are indigenous and extremely practical.

The water bodies created or developed for irrigation and drainage purposes are invariably utilized for catching and breeding fish.

The bottom mud of ponds and water courses, excavated to maintain hydraulic capacities of these facilities, is returned to cultivated land to fertilize the soil. It is a pattern similar to nature's own cycles and appears to be ecologically sound.

Land consolidation projects cover both cultivated land and fish ponds.

Irrigation and drainage systems are installed to serve crop production and aquaculture, and also navigation.

In short, irrigation and drainage projects are planned and executed to ensure the fullest use of land and water resources.

3.13.2 Recommendations

No doubt other countries have achieved much by way of gigantic water resources development projects that require sophisticated technical knowledge of design and construction engineering and huge capital outlays. But developing countries may first benefit by studying closely:

  1. small-scale water development projects in China being planned, built and managed by the farmers themselves at the commune and farm level at minimal cost using indigenous resources and materials;

  2. integrated and intensive management of land and water resources for agriculture and fish production at the farm (commune or brigade) level; and

  3. crop production, animal husbandry and fish culture/catching technologies adopted and performed by farmers in an integrated manner.

For this purpose the following courses of action are recommended:

  1. A study tour of China for one month or more by key government officials of member countries with a view to obtaining a general idea of the Chinese way of thinking and performance, and to identifying the areas of detailed study and training by their colleagues.

  2. In-service training of technicians, extension workers and farmers at the farm level (commune and brigade) for a period of three to six months.

  3. Setting up pilot demonstration-cum-training projects in member countries to be managed by Chinese technicians and farmers.

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