Māris kļaviņŠ, azamat azizov, JĀnis zaļoksnis environment, pollution, development: the case of uzbekistan

Figure 9.8. Structure of 
use of agricultural lands 
in Uzbekistan (th. km
2
)

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9. POLLUTION OF SOIL 
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Desertification  is  land  degradation  in  arid  and  semi-arid 
areas resulting from various factors including climatic conditions 
and  human  activity.  Deserification  affects  the  living  conditions 
of rural people, who depend on livestock, crops, limited water 
resources  and  fuel  wood.  Desertification  is  the  most  actual 
problem for drylands (arid, semi-arid and dry sub-humid areas). In 
drylands  desertification  risks  creates  low,  infrequent,  irregular  and 
unpredictable precipitation, large variations between day and night-
time temperatures and low amounts of organic matter in soils. When 
land degradation happens in the drylands, it often creates desert-
like conditions and can be defined as desertification. Desertification 
destroy elemental biogeochemical and biological cycles and have 
serious consequences for the environ ment. Desertification is caused by 
human activities, such as overgrazing, over-cultivation, deforestation 
and poorly planned irrigation systems as well as extreme climatic 
events, such as droughts. Desertification occurs because drylands are 
extremely vulnerable to over-exploitation and inappropriate land use, 
but the consequences are reduced food production, soil infertility, 
reduced water quality, sedimentation in rivers and lakes, and silting 
of reservoirs, aggravation of health problems due to wind-blown dust, 
including eye infections, respiratory illnesses, allergies, and mental 
stress, loss of acceptable living conditions. 
Another  major  environ mental  problem  is  soil  salinization  in 
irrigated lands,as far as water from underground reservoirs is often 
polluted, but evaporation brings mineral salts to the sur fa ce, resulting 
in high salinity. Increased soil salinity makes the soil unsuitable for 
crops which cannot withstand high salt con centra tions. In Uzbekistan 
saline soils compose 65.9% of irrigation area, including mild salted – 
33.9%, salted – 19.4%, highly saline – 12.6%. At irrigation territory 
of Uzbekistan 8% of soil is subjected to irrigational erosion, 2% of 
them is in moderate and in severe measure.
In Uzbekistan around 50% of all irrigated soils are considered 
saline.  Saline  soils  are  widely  spread  in  the  Karakalpakstan,  in 
Buhar, Navoji and Sirdarjensk region. Almost 5% of area of irrigated 
soil – 213.1 thousand hectares is noted as strongly saline. 
More than a half of the areas located on alluvial plains suffer 
from salinity and excessive moisture. Salinity is not only a reason of 
irrigation, which is characteristic for all intermountain, alluvial and 
proluvial territories of arid zone. Main reasons of soil salinization 
is  irrigation  without  drainage,  huge  water  losses  due  to  filtration, 
construction of irrigation channels without hydro isolation, excess 
of  irrigation  standards,  uncontrollable  water  flow,  irrigation  with 
mineral water. 
So, for example, annual increase of salts in irrigated salts of Ka-
ra kalpakstan is 10-30 tons per hectare. With increase of salinity of 

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ENVIRONMENT, POLLUTION, DEVELOPMENT:  THE CASE OF UZBEKISTAN
irrigation water and soil the fertility level of crops is decreasing. So, for 
example, fertility of cotton in the last years has decreased in Khorezm 
region from 39-41 centner per hectare (c/hect) to 29-33 c/hect, and 
in Karakalpakstan from 30-34 c/hect to 14-24 c/hect.