Contents - Previous - Next

H. Drylands development and combating desertification

3.41 Combating desertification in CIS countries has a long tradition. In 1912 a research station was founded in Repetek whose purpose was to protect railroads from sand encroachment. This problem has since held a very important place in the work of research centres; results of experiments have been put into practice on a large scale. Various methods of sand dune fixation have been used, such as wood or metal fences, spraying sands with petroleum or its derivatives (in several locations in the Muzhun-Kum Desert, near the railroad, the remains of bituminous covers, damaged and disintegrating, can be seen), and the planting of trees and bushes, especially Maloxylon sp. Generally, on any given terrain, one or two methods are combined, thus increasing the efficiency of sand dune fixation (cf. bibl. entry 8).

3.42 In the 1940's and 50's in the Ukraine, forest strips were planted in a more or less rational way. Today a number of research centres scattered in various CIS countries help in the selection of optimal systems of planting forests (the centres at Ashkhabad, Alma Ata, Baku, and the Panrussian Scientific Institute of Soil Conservation and the Prevention of Erosion at Kursk -Vs´erossi´ski´ naouchno-issl´edovat´el'ny´ institut z´eml´ed´eli´a i zashchity pochv ot erozii). Wind-breaks significantly slow down the speed of the wind, but the results depend on the width and height of the strips, the distance between them and the species of tree used. For example, in Dagestan a strip of forest 160 m long, 7 m wide, and 3 to 4.5 m high, composed mainly of acacias, caused the wind to decrease from 9 m/s to 1.4 m/s (measured 10 cm above the level of the soil), but 100 m behind the strip the speed of the wind increases again to 4.9 m/s (bibl. entry 1). Beneath the forest there is an increase in humidity and an improvement in the soil structure which allows the simultaneous cultivation of trees and other plants (for example, north of the Caspian Sea, wheat is sown between rows of elm and tamarisk.

3.43 Revegetalization plays a very important role in the management of saline soils (cf. bibl. entries 5, 14, 22, 104, 128). Several experimental projects have been carried out by the centres in Alma Ata, Ashkhabad and Tashkent. The revegetalization of saline lands requires a preliminary preparation of the soil, an improvement in hydrological conditions and a careful selection of plants. Although the methods applied are quite varied, it is almost always necessary to construct a drainage system (canals, furrows). To the north of the Caspian Sea, the cultivation of sorghum is recommended. The stalks left for the winter will retain the snow. Precipitation is light, and since snow is not stopped by obstacles in the topography, it is blown away by the wind. For this reason these areas are called "black lands. " The snow, retained by the sorghum, melts and contributes to the formation of a thin layer of fresh groundwater which settles on top of the saline water. There have also been experiments where wind-breaks have been planted, with sorghum, maize, "Sudan grass" and even wheat sown between them.

3.44 In the management of small areas where the soil is saline and not very permeable, good results have been obtained by bringing in sand (140 - 160 t/ha) and ploughing it into the soil. Successful experiments have been carried out on the promontories of the Alta´ where there are small saline depressions (cf. bib. entry 131).

3.45 In the management of the Aral Sea, a series of methods must be used to limit salt movements. Work must be intensive, carried out during the first 4 to 7 years after the soil is exposed, when the groundwater is still not very deep even if it is saline. The Botanical Institute of the Academy of Sciences of Kazakhstan recommends several plants for revegetalization (especially the saxaouls 2 and various psammophytes: Halaxylon aphyllum, H. persicum, several species of the genus Calligonum - notably C. caput-mendousae, Tamarix hispida and others), and different techniques of soil preparation (deep ploughing of solonchaks, creation of furrows, installation of bituminous covers on moving sands, etc.). In certain cases it is possible to seed grasses and saxaouls on barkhans 3 with no soil preparation, preferably by plane.

2 Small shrubs with thick stalks and cylindrical crowns, of the genus Chenopodiaceae-Salsola.

3 Crescent-shaped dune which progresses onto a non-sandy area.

3.46 CIS countries have a wide experience in revegetalization and the improvement of saline soils which could be utilized in other regions of the world. Unfortunately, the dissemination of this experience is not systematic, and even other CIS countries do not always benefit from it. During an interview, researchers at the Botanical Institute of the Academy of Sciences of Kazakhstan complained that the dried up bed of the Aral Sea was seeded by plane with grasses and shrubs without taking into account the characteristics of the soil and without prior preparation, with totally ineffective results.

3.47 Revegetalization methods are also used in the management of desert zones. Species with highly developed root systems are preferred, the best being creepers (a good example is Glycyrrhiza glabra L.). In nearly every issue of the periodical "Probl´emy osvo´eni´a pustyn " there is some information on the qualities of particular species and recommendations on their cultivation. Preferred species are the saxaouls (especially Halaxylon aphyllum and H. persicum), Kochia prostrata, and Glycyrrhiza glabra L.. The latter is useful not only for sand dune fixation but also provides raw materials for the pharmaceutical and food industries. Its roots can be used for animal feed (at the end of two years, with irrigation, 16 to 18 tonnes of dry root matter were obtained: cf. bibl. entry 55).

3.48 In sand dune fixation, revegetalization is often used in conjunction with other methods: construction of fences or installation of covers which prevent water from seeping deeply into the sand. The choice of height (generally 20 to 70 cm) and distance between fences is made according to the direction and force of the wind. Since the fences are built mainly from branches and brush, there have been cases where vegetation has been destroyed to build fences. In Turkmenistan chemical methods of sand dune fixation were used in the early 1980's near roads and industrial establishments; among known methods, the use of petroleum derivatives and bitumens was the least expensive. Petroleum guarantees the fixation of dunes for two years, polymers for two to three years, and some oil mulches for five years (cf. bibl. entries 8, 12, 14, 67 and others).

3.49 There is a completely different group of methods for combating desertification that does not disturb (or disturbs to a minimal degree) the natural environment. These are often very simple methods: A. Arnag´el' dy´ev (cf. bibl. entry 64) recommends taking into account the direction of the dominant winds in deciding the location of villages, roads and factories. He emphasizes that for the management of takyrs 4, herd routes must be planned downwind from takyrs; otherwise, the sand kicked up by hooves will be blown towards the fields by the wind. The management of takyrs requires an improvement in hydrological conditions that is, the construction of a canal system and shallow furrows (cf. bibl. entry 45).

4 See annex 5.

3.50 Revegetalization plays an important role in rational pasture use. Scientists in the Soviet and post-Soviet periods have considerable experience in this. There exist optimal norms of acceptable grazing which take into consideration the flora and its condition. There are also descriptions of the stages of degradation and methods of revegetalization, and of additional techniques such as ploughing (cf. bibl. entries 81, 118, 119 and others). Most works concerning pastures do not take into account economic considerations; it is only in recent years that this situation has changed. It is worth mentioning here the study by B.V. Vinogradov et al. (cf. bibl. entry 56) which presents a model for pastures north of the Caspian Sea. This is a model for attaining high financial profits from livestock farming; during the first years of the development period, revegetalization must cover 20% to 25% of pastures per year, then 10% to 15% per year, until over 80% of the territory has been improved, with 0.6 sheep/ha. This system could give excellent results in the Aralo-Caspian depression.

I. Results of large-scale projects in drylands development and combating desertification

3.51 It is difficult to determine the precise effects of desert management and of combating desertification. Very concrete assessments can be found in the Moscow press, but they must be interpreted with caution.

3.52 Although statistics can be inexact, and the 1960's, 70's and 80's were dominated by the "propaganda of success," it is nevertheless certain that large irrigation systems have allowed the significant extension of the area of arable land and an increase in harvests. In 1971 in Tajikistan, the length of all the irrigation and drainage canals added up to 142,600 km; today it is around 200,000 km. In other countries of the CIS the length of canals is less; in Turkmenistan, the total length of canals in 1971 was 20,000 km, and in 1982, there were 25,046 hen of irrigation canals and 20,237 km of drainage canals (cf. bibl. entries 12, 22). Considering that the surface area of oases has increased from 1 % to 7% of the total area of Turkmenistan from the 1950's to the end of the 1980's (cf. bibl. entry 75), it is clear that a significant quantitative change has taken place (although it can only be approximated).

3.53 Programmes for developing arid and semi-arid lands and for controlling desertification reached their peak in the 1970's and the beginning of the 1980's.

3.54 The considerable expansion of irrigated areas (cf. chaps. 4.D) has been accompanied by the rapid development of sand dune fixation projects and the creation of forest strips. The greatest successes in sand dune fixation have been recorded in Turkmenistan. 140,000 ha were stabilized between 1951 and 1968, 300,000 ha between 1971 and 1975, and 330,000 ha between 1976 and 1980. Subsequent projects, very ambitious, planned the fixation of all the dunes of Turkmenistan and almost all those in other Republics by the year 2000 (estimations of the area of sand dunes in Turkmenistan vary widely, although the figure most often cited is 1.3 million ha in 1980) (cf. bibl. entries 8, 12, 22, 46, 139).

3.55 As for forest strips, the areas decrease regularly, from 44,000 hectares in 1980 to 39,000 hectares in 1985, and 29,000 hectares in 1987 (cf. bibl. entry 50). Pryde indicates that he can find no explanation for this. He seems to connect it with the beginnings of the collapse of the Soviet economy.

3.56 Positive results in the combat against desertification and drylands management are particularly visible in certain privileged regions.

3.57 The afforestation of lands along the railroad was undertaken to protect the tracks from sand encroachment. In Turkmenistan, the afforestation along the railway covered 150 ha/year (cf. bibl. entry 12). In May 1993, along the Moscow-Saratov-Akhtiubinsk-Alma Ata rail line, through 3,000 km of steppes, semi-deserts and deserts, there is an almost continuous strip of forest, interrupted by only a few gaps.

3.58 Baku is a good example of successful urban afforestation. In 1950, parks covered only 309 ha in Baku, but increased to 1,160 ha in 1960 and to 5,500 ha in 1970. Subsequent years have recorded a continual growth in wooded areas.

3.59 However, generally speaking, the programmes of managing arid and semi-arid lands have been a fiasco with disastrous consequences. It is exactly these large-scale projects - ploughing the steppes and irrigation schemes which absorb enormous quantities of water which are considered to be the main causes of desertification (cf. chaps. 4.F). As a result of these errors, the combat against desertification has become at the same time a factor of desertification - a vicious cycle of degradation. To break it, technical solutions, even the best, are not sufficient; profound changes in the social structures are necessary.

3.60 The countries of Central Asia are currently suffering from an ecological catastrophe which is habitually called the "Aral problem." It is comparable to what happened in the 1930's in the prairies of the United States, and is as serious as desertification in Africa. Lake Balkhash, somewhat less threatened, has remained in the shadow of the "Aral problem." The dangerous situation of the Aral Sea has long been known. A close analysis of the recent evolution of ideas and proposals to solve the "Aral problem" gives hope that structural changes will finally take place.

3.61 Until the 1970's, the dangers were generally ignored. Politicians almost uniformly considered that the diversion of Siberian rivers would solve all the difficulties. They proposed a canal linking the Ob River to the Aral Sea. There was also a plan for a canal that, after connecting the Yenissey and Ob Rivers to the Aral Sea, would continue west to the lower Volga and the Caspian Sea (more than 3,000 km, 25 km3 of water/year). Detailed management plans for lands near the projected canal were developed (cf. bibl. entries 11, 17, 27). Only at the end of the 1970's and the beginning of the 1980's were the enormous costs and the possibility of the negative ecological impact of such undertakings considered, especially since the errors made in the construction of the Karakumy Canal were fresh in their memory (cf. bibl. entries 17, 87).

3.62 The idea of transferring water from Siberian rivers towards Central Asia was abandoned very recently. However, the question of the future of the Aral Sea is still open. Most often, the plan is to divide the Aral Sea into several separate reservoirs. But even this solution requires a water supply, and the Amu-Darya and the Syr-Darya are nearly dry. The diversion of Siberian rivers being currently impossible, certain authors propose transporting water from the Volga and the Caspian Sea. However, considering the very high cost and the general political situation in the region, this project is unworkable at this time. More and more often, the idea of rational economy (economizing water, improving irrigation and drainage systems, changing crops, etc.) is advocated as the best solution to the problem (cf. bibl. entries 32, 43, 77, 123, 132). Similar propositions have been put forward in the case of Lake Balkhash. For example, G.M. Janali´eva (cf. bibl. entry 94) estimates that the water use norms for irrigating rice fields in the Ili valley can be reduced from the current 50,000 - 60,000 m3/ha to less than 25,000 - 30,000 m3/ha. A decrease in water consumption would only be possible if there were a fee for water use, and land reforms (cf. bibl. entries 26, 32, 43).

3.63 S.I. Bobyl´ev takes these ideas further (cf. bibl. entry 77). He proposes giving up the monoculture of cotton in Central Asia and starting the production of synthetic fibres instead. In his opinion, this change could economize up to 40 km3 of water/year with a much lower cost than other solutions. Although these estimations are questionable, they nevertheless express a new way of thinking.

Contents - Previous - Next