干旱区生态环境知识资源中心

Middle Asia is submitted to arid and semiarid cold winter Mediterranean climate with lower precipitation variability than in other Mediterranean regions. It harbors the Irano-Turanian flora closely related to the Mediterranean basin. It encloses the newly independent countries (i.e., Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan and southern Kazakhstan) that had to produce their own food and feed within their national territory after the Soviet system breakup in 1991. Rangelands cover most of these countries (80-95% of total agricultural areas) with little arable land (5-20%) and permanent crops (0.1-2.9%), the last two being mostly irrigated, except in Kazakhstan. After 1991, Middle Asian agriculture deteriorated due to disorganization and ensuing slow reform generating a breakdown in farming practices, fertilizer use, and crop yield until 1995-1997, and then picking up again. This revival was achieved by reassigning cotton- and rice-irrigated land to irrigated wheat cropping, and also to rainfed cereal cropping competing for the best rangelands, except for Kazakhstan. As a result, rainfed barley feed dropped radically, impacting the small ruminant population forcibly fed on meager rangelands. Furthermore, forage production collapsed too and with supplementary feeding disappearing, the small ruminants population shrunk dramatically in Kazakhstan, Kyrgyzstan, and Tajikistan. It remained stable in Turkmenistan and Uzbekistan, hence increasing grazing pressure on all rangelands. With range yields averaging 180 kg DM ha(-1) a(-1) in Karakum and Kyzylkum under 100-150mm precipitation and currently practiced stocking rates (about 5 ha Sheep Equivalent(-1)), range use factors appear to exceed 100%, indicating potential desertization. Rangeland poor condition is confirmed by the low Rain Use Efficiency of 1.3 kg DM ha(-1) a(-1) mm(-1). This unrestrained combination of escalating pressure for food on agricultural land and for feed on rangelands leads to slow catastrophic desertization as observed in North Africa and the Middle East.