Distribution patterns of soil algae were investigated in a 14-year-old farm and its surroundings in the salinized irrigation land of Central Asia. Using a culture dilution method, the densities of five groups of soil algae, green colony group (composed of chlorophytes together with xanthophytes), Chroococcales, Oscillatoriales, Nostocales in the orders of blue-green algae, and diatoms, were estimated. The differences in the distribution patterns among the green colony group, the Oscillatoriales and the N ostocales attributed to soil salinity and soil moisture. As the green colony group was more sensitive to salinity than the blue-green algae, the density decreased at a relatively higher salinization level (EC>ca. 8 dS m-1). The blue-green algae, especially the Nostocales, were not affected by such degree of salinization. However, the nostocalean blue-green algae also could not occur in the further developing safinized part where salt crusts were observed. These results show that few soil algae occurring at the study site were able to adapt to the land with high salinity induced artificially. Around the sand dune where salt accumulation had never occurred, several species belong to the green colony group were dominant and few blue-green algae were observed. This observation suggests that these species had developed some strategies to tolerate water stress because this area was subjected to extremely dry conditions.

Distribution patterns of soil algae were investigated in the 25-year-old Bakbakty farm and its surroundings in the flood plain of the River IIi, Kazakstan. U sing a culture dilution method, the soil algal density was estimated. Soil algal density in the study site was lower by almost one order than that in the 14-year-old Bereke farm ca. 60 km apart which was previously studied. This difference and the results of the distribution pattern of electric conductivity suggest that salinization was more advanced in the older farm. Multiple linear regression analyses revealed that the density of the green colony group composed of chlorophytes together with xanthophytes was strongly influenced by the soil salinity. On the other hand, the water content in soil was more important than the effect of soil salinity for the distribution of nostocalean blue-green algae. These findings were in good agreement with the results of the previous study. The usefulness of the green colony group as an indicator of soil salinity, was discussed.Key Words: arid region, Central Asia, irrigation land, salinization, soil algae. 67Salinization of irrigated lands is one of the most serious problems in the world. Many croplands have been abandoned due to this effect. Many kinds of soil algae, especially filamentous blue-green algae, have been detected in saline soils (Shtina and Bolyshev 1960;Ali and Sandhu 1972;Novichkova-Ivanova 1980;Arif 1992). Utilizing the wide adaptability of blue-green algae in saline habitats, some attempts to ameliorate salinized agricultural land have been conducted in India (Singh 1961;Kaushik 1989). Few quantitative studies, however, have been undertaken to estimate the density of soil algae in salinized irrigation land.Irrigated lands of Central Asia also experience increasing salinity and the salt-affected soils cover more than 200 million ha (Szabo1cs 1986). In a previous paper, we showed that salinization of a cropland and its surroundings was progressing in the 14-year-old Bereke farm located in the flood plain of the River Hi, Kazakstan (Kosaki et al. 1993). In a series 1 Present address: Lake Biwa Research Institute, 1-10 Uchidehama, Otsu, 520-0806 Japan. of papers, we investigated the distribution patterns of soil algae at the same site (Tsujimura et al. 1998). The results of the study suggested that blue-green algae, especially the Nostocales, were more tolerant to salt than eukaryotic algae which mainly consisted of green algae. However, in the areas where salt crusts were observed on the soil surface, most of the algae including the Nostocales could not be detected.To clarify further the standing crop of soil algae in the salinized irrigation land, we carried out quantitative studies on the soil algae at Bakbakty farm, Kazakstan and compared the results obtained with those recorded at Bereke farm. As an irrigated land, Bakbakty farm has a 10 y longer history than the Bereke farm. MATERIALS AND METHODSBakbakty farm (N44.35, E76.53) is situated in the flood plain of the River IIi ca. 60 km away from the Bere...

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This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Kazakhstan is an agrarian country with 270 million hectares utilized for animal and crop production. The foremost objective of the state agriculture programs in Kazakhstan is to achieve food security of country on the basis of competitive crop production. Demand for soybean as an oil crop and animal feed is steadily growing in Kazakhstan and hence soybeans can be a great attribute for food security in this region. Currently, over 90% of all soybean production is concentrated in one region (Almaty) because the crop is highly sensitive to photoperiod and temperature. The climatological conditions in majority of the region pose difficulties in growing the soybeans. In this review, we discussed the impact of the geographical and environmental conditions in enhancing the soybean cultivation in different parts of Kazakhstan. Additionally, we have taken an account of current status of soybean production and the barriers that may have great influence on the soybean yield. Because soybean is a short-day plant, the main role in its adaptation to areas in Kazakhstan is played by its E genes (maturity and flowering genes), the exploitation of which constitutes the primary challenge for the expansion of soybean cultivation. Besides, we have proposed candidate regions for soybean expansion, including Almaty, Zhambyl (south), East Kazakhstan and Kostanay (north). Expanding soybean production in Kazakhstan and in Central Asia could be addressed using competitive education, application of modern scientific methods and cutting-edge breeding technologies, appropriate financing, and productive strategies to develop superior cultivars with tolerance to abiotic stresses.

Kazakhstan is an agrarian country with 270 million hectares utilized for animal and crop production. The foremost objective of the state agriculture programs in Kazakhstan is to achieve food security of country on the basis of competitive crop production. Demand for soybean as an oil crop and animal feed is steadily growing in Kazakhstan and hence soybeans can be a great attribute for food security in this region. Currently, over 90% of all soybean production is concentrated in one region (Almaty) because the crop is highly sensitive to photoperiod and temperature. The climatological conditions in majority of the region pose difficulties in growing the soybeans. In this review, we discussed the impact of the geographical and environmental conditions in enhancing the soybean cultivation in different parts of Kazakhstan. Additionally, we have taken an account of current status of soybean production and the barriers that may have great influence on the soybean yield. Because soybean is a short-day plant, the main role in its adaptation to areas in Kazakhstan is played by its E genes (maturity and flowering genes), the exploitation of which constitutes the primary challenge for the expansion of soybean cultivation. Besides, we have proposed candidate regions for soybean expansion, including Almaty, Zhambyl (south), East Kazakhstan and Kostanay (north). Expanding soybean production in Kazakhstan and in Central Asia could be addressed using competitive education, application of modern scientific methods and cutting-edge breeding technologies, appropriate financing, and productive strategies to develop superior cultivars with tolerance to abiotic stresses.