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<Forum on the Caspian, Aral and Dead Seas-Perspective Present Problems and Future Prospects of Paddy Fields in Kazakhstan Tsugihiro Watanabe The shrinkage of the Aral Sea has been induced by large scale irrigated agriculture rapidly developed in its basin. It is said that paddy fields, which use much water, have caused the changes in hydrological regime. So, their present problems and future prospects are discussed on the irrigation management aspect. Then, improvement of on-farm irrigation facilities and re-establishment of managing organization is recommended. 1. Introduction The problem of desiccation of the Aral Sea in Central Asia has attracted worldwide attention. Changes in hydrological regime in the basin are said to be induced mainly by large scale irrigated agriculture, which diverts much water from the Syr-Dar'ya and Amu-Dar'ya Rivers running into the Aral Sea. Even in the irrigated area, some parts are facing salinity damage caused by inadequate irrigation management. The Aral Sea basin is one of the main rice growing areas in the former Soviet Union. Rice production in this area requires much water diversion from the rivers, resulting in environmental degradation. In this paper, paddy fields and rice irrigation in this region, mainly in Kazakhstan, will be discussed. Up to the present, their actual feature has not been clearly revealed with reliable information, however, present problems and future prospects of paddy fields should be examined. So, a case study on a rice producing sowchos, which is located in the basin of the Ili River running into the Balkhash Lake in eastern Kazakhstan, will be effectively introduced (Watanabe, 1994) since the Balkhash Lake is also facing a similar lake shrinkage problem. 2. Rice Production In Kazakhstan 2.1 Rice production in the former Soviet Union First, rice production in the former Soviet Union will be outlined. In Russia, rice cultivation was mainly introduced in northern Caucasus in the 18th century, at that time encouraged by the Russian Tsar Peter I. In the 20th century, the government of Russia introduced rice production, for the first time, to the Far East (1910). In eastern Kazakhstan, along the Karatal River, rice plantings were experimented in 1929, and considerable land was developed for rice cultivation in the Ili estuary in the 1930s. In 1913, the total rice production area was 270,000 ha and the average yield was about 1.2 t/ha. The area had increased gradually, mainly from the 1960s to 1980s, to reach 666,000 ha in 1980, with an average yield of 4.2 t/ha (Konokhova, 1985). At present, nearly 90% of the total rice production area in the former Soviet Union is distributed in Russia, Kazakhstan and Uzbekistan. Their share in the total rice production area in the Soviet Union is 54%, 20% and 15%, respectively. The Kuban River Basin in northern Caucasus in South Russia is the largest rice production area. Its production is 50% of the Russian total. The second largest area is the Aral Sea basin in Kazakhstan and Uzbekistan. The third largest area is the lowland area in the Volga River basin and near the Caspian Sea (Ikehashi, 1987). In the former Soviet Union countries, rice is an irrigated lowland crop, seeded directly onto field plot and cultivated with a mechanized system. Rice cultivated areas are extended mainly in arid or semi-arid areas with less rainfall, where irrigation canal networks are well developed. In most rice growing areas, crop rotation is practiced since continuous rice cropping results in decreased yields, which makes the soil depleted in fertility and organic materials, and the deterioration of the physical conditions of soil (Konokhova, 1985). 2.2 Rice Production in Kazakhstan In the Republic of Kazakhstan most of the land is classified as steppe or desert with annual average precipitation of 100-200 mm. In the northern part, wheat is a predominant crop, whereas rice, cotton, fodder and fruit are produced in the southern part. The total cropped area was only 4.14 million ha in 1913, but increased, due to rapid land reclamation mainly in the Syrdarya basin since the 1950s, to 36.4 million ha in the 1980s. The present total cropped area is nearly 14% of the total area of Kazakhstan. The irrigated land of total 7.6 million ha in the Aral Sea basin became one of the big food supplying sources of the Soviet Union and Eastern Europe. In the Aral Sea basin, cotton is the main irrigated crop covering 50.6% of the total irrigated area. Fodder is also grown widely with a crop area of 22.3% of the total. Total rice cropped area in the Aral Sea basin is 428,600 ha, of which 56% is in the Syrdarya basin, and the remaining 44% in the Amudarya basin. While rice occupies only 5.6% of the irrigated area, its water requirement is about 15% of the total irrigation requirement (Zhu and Raskin, 1991). In Kazakhstan, irrigated land is located mainly in the Kazakhstan part of the Syrdarya River basin, which is concentrated in South-Kazakhstan and the Kzyl-Orda areas Most of the rice cropping area in Kazakhstan is also distributed in two regions. The present total rice area in these regions is about 113,000 ha, which is equivalent to 17% of the total irrigated area as shown in table 1. More than 80% of the total rice production in Kazakhstan depends on the rice growing area in the Kzyl-Orda area.
Table 1. Cropping Area in Two Main Irrigated Regions in the Syrdarya basin
Rice cropping area in the Kzyl-Orda region had increased from the 1940s, reaching 100,000 ha in 1985 (table 2). Since 1985, however, the rice producing area has gradually reduced, while the total irrigated area has slightly increased. The recent trend of the rice yield in the two regions is tabulated in table 3, showing that the present yield is estimated as 4.5 to 6 t/ha and the average yield has a tendency to decrease.
Table 2. Changes in Irrigated Area in Two Main Irrigated Regions in the
Syrdarya Basin
Table 3. Changes in Average Rice Yield in Two Main Rice
Growing Regions in the Syrdarya Basin
In the irrigated area in Kazakhstan, the crop rotation system is dominantly practiced with several rotation patterns, for example, the cotton pattern, the rice pattern, etc.. Rice is grown usually in this crop rotation system of rice pattern, which has two main variations: an eight-year rotation or a six-year rotation. In the former system, rice, alfalfa with barley, alfalfa, rice are planted in turns of two, one, two, two years respectively, and a field lies fallow in the last year, indicating that rice is grown in 50% of the total cropping area. There are a total of 333 rice pattern systems with 218,000 ha in the South-Kazakhstan and the Kzyl-Orda regions. Reliable statistical data of rice cropping area in Kazakhstan is not readily available. One of the reasons is the confusion of the actual rice planned area and the area under rice pattern crop rotation system and the difference between the actual and the planned rice crop areas. 3. A Case Study: Rice Producing Sowchos in the Ili River Basin 3.1 Bereke Farm and its Agriculture The Bereke Farm, which is a typical rice producing sowchos in Kazakhstan, is located in the Ili River basin between Almaty and Lake Balkhash. It was established in 1979 in a newly reclaimed area in the desert. Its total area is 13,913 ha, of which 5,172 ha is farmland, and its population is about 1,700. Annual precipitation at Bereke is estimated as 150-200 mm, and monthly rainfall in summer is less than 20 mm and not effective for rice growing. It is very cold in winter, but very hot, and suitable for rice growing in summer. In the Bereke Farm, the eight-year rice rotation system is practiced. In 1993, the rice growing area was estimated as 2,100 ha. Wheat and vegetables are also grown in small parts, and about 1,000 beef cattle and 50 horses are grown. Agricultural practices have been carried out by cooperative works under the sowchos system using huge agricultural machines including 110 tractors and 70 combines. 3.2 Irrigation and drainage system In the Bereke Farm, all crops are irrigated depending on the Ili River, with flow discharge regulated by the upstream Kapchagai reservoir constructed in 1966. Irrigation water is diverted from the Ili River and conveyed by a principal irrigation canal managed by an organization consisting of several sowchoses. The Bereke Farm is the furthest downstream farm to benefit from irrigation. The irrigation season, usually from the beginning of May to early September, and schedule are decided by the organization under the direction of the government. Surface drainage water flows eventually into the main drainage canal, running around the sowchos and into the Ili River at 30 km downstream of Bereke. Canals, both for irrigation and for drainage, are generally not lined and their beds are just like sand dunes. The principal canal branches off into four main distribution canals, which have also diversion works to field irrigation canals. Three special technicians are in charge of operating the facilities above the branch level in the Bereke Farm. On-farm irrigation facilities are managed by field agronomic technicians. These facilities are not well maintained due to shortage of budget and lack of recognition of maintenance. Water demand for irrigation is calculated by planted area and standard duty for each crop. Designed irrigation efficiency in the sowchos is fixed as 60%. In 1993, annual water requirement from May 11 to August 31, was set for each crop. For example, 3,100 mm for rice, 395 mm for barley or wheat, 510 mm for fodder, etc.. This means that the net annual water requirement is about 1,863 mm for the total cropped area of 5,202 ha. The gross requirement including the losses in the distribution system in the farm is calculated as 3,105 mm. 3.3 Paddy field and rice production Rice can be grown in all fields and every year almost half of them are used for rice cultivation. A standard plot is rectangular in shape with 2.5 ha of dimensions 125 m x 200 m. It is adjacent to a field farm ditch and a farm drain. Bunds surrounding it are very large. One application inlet pipe and one surface drainage outlet pipe are set in the bund. Figure 1 depicts the typical layout of field, canals and road.
Figure 1: Typical Layout of Fields with Canals and Roads in Rice Producing Sowchos Soils in the fields are classified as silt loam or silty clay loam. Top soil in unreclaimed land outside the farm is more sandy (Kosaki, 1993). In April, paddy fields are cultivated and leveled, and then fertilizers are applied. Just before the release of irrigation water, they sow seeds directly onto the dry field, after which the first application of water immediately follows. In the initial stage, ponding is shallow and according to development of seedlings the water depth is increased and maintained at a 10 to 15 cm level until about 20 to 30 days before harvesting. Ponded water is sometimes replaced by fresh irrigation water, as a countermeasure for salinity. Generally, water is applied 10 to 15 times in one season. Average yield of unhulled rice is estimated as nearly 4 to 5 t/ha. Water requirement for rice is considerably high. In 1993, standard annual on-farm water requirement was 82.45 million m3 for 2,100 ha, based on the table of water use planning. That table gives the requirement for each 10 days as shown in figure 2. During the irrigation season, the applied water in the plan was more than 40 mm/d, which is very high even with a high evapotranspiration rate. Total estimated net requirement was 3,926 mm per year and the gross water demand including distribution losses was 6,562 mm.
Figure 2: Water Requirement for Rice in the Bereke Farm (1993) Actual water use and consumption of rice was compared with the planned one in the Akdala area including the Bereke region. The results are shown in table 4. Though actually applied water is less than that planned, the table depicts the general feature of water use in paddy fields where total water requirement is about 2,500 mm. About 1,000 mm and 800-900 mm is consumed through evapotranspiration and percolation, respectively. Table 4. Water Use and Consumption of Rice in the Akdala Area
3.4 Irrigation Induced Environmental Issues In the Bereke Farm, a large amount of seepage water from canals and fields, mainly paddy fields, contribute to the rise of groundwater table during irrigation season. In other words, it can be said that higher groundwater levels and high soil water content allow crop growing in non-paddy fields only by less water application. Though the net water requirement in paddy fields is about 4,000 mm per one growing season in the plan, the actually applied water to the fields is estimated as about 2,500 mm. This means that daily water requirement in the fields is about 25 mm and water application is practiced every 4-6 days resulting in 10 to 15 times of application in total in one season, as mentioned previously. This waterlogging, widely spread in most of the sowchoses and the surrounding unreclaimed area, induces some problems. One harmful problem is the high soil moisture in the settlement area. It is alleviated by using 5 groundwater pumps to lower the water table. Their drinking water depends lifting the groundwater inside the settlement. While seepage water recharges groundwater resources, there is a risk of groundwater pollution or contamination by inflow of agricultural chemicals and nutrients. A more fundamental problem is, however, salinity in the field caused by water-logging. In some places with a high water table, for example, in fields near irrigation canals, salt accumulates on the surface of the soil profile. Ponding water in paddy fields is effective for leaching out the accumulated salts from soil profile.
4. Present Problems and Future Prospects of Paddy Fields in Kazakhstan It is a fact that in paddy fields in Kazakhstan much water of surface water is used resulting in decline of flow discharge of the rivers, even though the relation between irrigation and hydrological regime has not been evaluated quantitatively. It is usually said that the design capacity of canals in the rice irrigation system is considerably large and irrigation efficiency is quite low. Actual circumstances about the irrigation water use, however, also have not been clear. Generally the capacity of farm irrigation ditch is 15 to 20 l/sec/ha, and 5 to 6 l/sec/ha is adopted for farm level canals. Designed irrigation efficiency is 0.7 to 0.85 in a farm system and is 0.80 to 0.90 in a conveyance system, resulting in 0.55 to 0.75 as a total system irrigation efficiency. To make irrigation efficiency higher and to save water resources, it is necessary not only to implement irrigation and drainage system improvement and water management projects but to examine the total cultivating system including the land use program or the crop rotation systems. Some engineers recommend that rice production should be reduced by 30 to 40% in the area, because of the over production of rice for domestic consumption in Kazakhstan. The rice producing area is affected by agricultural production in the whole of the CIS. The principle of future paddy fields depends upon the trend of the agricultural system decided by socio-economic changes, which are not easy to anticipate. Who actually produces the rice and how that rice is produced, affects the condition of the paddy fields and the irrigation system of it. If the present cooperative rice cultivation with big machines succeeds for the time being, it would be useful for efficient water use in paddy field to improve on-farm irrigation canals including lining and to establish effective water management systems with great responsibility consisting of water users and present experts. To realize effective and environmentally sound water use, it is important for water users to be spontaneously aware of taking part in water use and control. Sometimes, collection of water fees from farmers for some parts of operation and maintenance costs, even if only a very little amount, would be significant.
5. Conclusion Generally, rice production in a desert or an arid land can produce high yields if good conditions for rice growing are available like a reliable water supply, which often needs additional water resources development. This development may induce significant changes in large scale geo-hydrological regimes and disruption of natural ecosystems. On the other hand, water ponding in paddy fields brings downward water flux and flushes out soil salinity, contributing to conservation of soil productivity in crop rotation. As to paddy fields in Kazakhstan or in other regions in the Aral Sea basin, diagnostic study on actual rice production, including irrigation performance and its effects on hydrological environment, is an urgent subject, which has not been systematically tackled in spite of wide recognition of it. Though future prospects of paddy fields should be discussed using results of the diagnostic analyses of the present problems, it is clear that improvement of on-farm facilities and establishment of effective water management organization is inevitable for a foundation of future paddy fields. To implement these diagnostic studies and rehabilitation programs, financial and technical aid from abroad is requested and collaborated academic works between Kazakhstan researchers and foreign scientist groups should be rapidly progressed. References: Ikehashi, H. (1987) Rice Production in the Soviet Union. p.145-159. Rice and Rice Cultivation in the World. Special Issue of Agriculture and Horticulture No. 62. (in Japanese) The Kazakhstan Academy of Agricultural Science (1992) Rice Cultivation Environment in the Akdala Area. Almaty. (in Russian, unpublished) Konokhova, V. P. (1985) Rice Growing, Mir Publishers, Moscow. Kosaki, T. (1993) Desert Converted to Rice Field (Irrigation Induced Soil Salinization). p.57-65. Annual Report of the Japan Research Association of Kazakhstan, Kyoto. (in Japanese) Zhu, Z. and P. Raskin (1991) Water Development Strategies for the Aral Sea Region. Proceedings of the 7th World Congress on Water Resources. Morocco. Watanabe, T. (1994) The Aral Crisis - Irrigation Induced Environmental Problems in Central Asia -. J. of Water and Environmental Issues. 7. (in Japanese)
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