Abstract:The rapidly growing population in Uzbekistan has put massive pressure on limited water resources, resulting in frequent water shortages. Irrigation is by far the major water use. Improving irrigation water use through the institutional change of establishing water consumer associations (WCAs) has been identified as a way to increase agricultural production and meet the food demand in the area. However, most WCAs are not fully able to organize collective action or generate sufficient funds to carry out their responsibilities. This study investigated the water-resource-related challenges faced by WCAs and local farmers in Kashkadarya Province in Uzbekistan, using semi-structured expert interviews and focus group discussions. The resulting data were analyzed using qualitative analysis software (Atlas.ti). The results indicated that outdated infrastructure, poor governance, and farmers' non-payment of irrigation service fees hamper sustainable water management. Greater trust and communication within the WCAs would make an important contribution to effective collective action and to the long-term sustainability of local associations.

The advantages of a nexus approach in addressing complex environmental challenges are becoming increasingly clear. In Central Asia, however, the nexus between water–food–energy has not received adequate attention, as the very few studies that have been conducted fell short of quantifying nexus trade‐offs and benefits at a practical, small scale. This paper applies a quantitative accounting method to assess water and energy use intensity in irrigated areas of the Karshi Steppe of Central Asia that are supplied by pumping water uphill (lift‐irrigated) from the underlying river. The results indicated that the potential water and energy savings as well as the greenhouse gas (GHG) emission reductions could be achieved by applying an optimal planning deficit irrigation schedule simulated using CROPWAT 8. Some 575 MCM (million cubic metres) of water and 259 GWh of electricity can be saved, while the CO2 equivalent emissions can be reduced by almost 122 000 t. Achieving these savings requires a mix of technical and policy components. This paper describes an example of proper irrigation planning as a tool for water/energy savings and consequent reduction of CO2 emissions. © 2019 John Wiley & Sons, Ltd.

Soil salinity negatively affects plant growth and leads to soil degradation. Saline lands result in low agricultural productivity, affecting the well-being of farmers and the economic situation in the region. The prediction of soil salinization dynamics plays a crucial role in sustainable development of agricultural regions, in preserving the ecosystems, and in improving irrigation management practices. Accurate information through monitoring and evaluating the changes in soil salinity is essential for the development of strategies for agriculture productivity and efficient soil management. As part of an ex-ante analysis, we presented a comprehensive statistical framework for predicting soil salinity dynamics using the Homogeneity test and linear regression model. The framework was operationalized in the context of the Khorezm region of Uzbekistan, which suffers from high levels of soil salinity. The soil salinity trends and levels were projected under the impact of climate change from 2021 to 2050 and 2051 to 2100. The results show that the slightly saline soils would generally decrease (from 55.4% in 2050 to 52.4% by 2100 based on the homogeneity test; from 55.9% in 2050 to 54.5% by 2100 according to the linear regression model), but moderately saline soils would increase (from 31.2% in 2050 to 32.5% by 2100 based on the homogeneity test; from 31.2% in 2050 to 32.4% by 2100 according to the linear regression model). Moreover, highly saline soils would increase (from 13.4% in 2050 to 15.1% by 2100 based on the homogeneity test; from 12.9% in 2050 to 13.1% by 2100 according to the linear regression model). The results of this study provide an understanding that soil salinity depends on climate change and help the government to better plan future management strategies for the region.

There is wide consensus among scholars and practitioners that improved irrigation technologies increase farm productivity and improve resource use efficiency. However, there is also growing empirical evidence that efficiency improvements in irrigation water use may create rebound effects, i.e., they may trigger changes in farmers’ behavior that partly or fully offset the technical water savings expected under ceteris paribus conditions. In extreme cases, total water consumption may even increase. We studied the impacts of introducing water-saving irrigation technologies in Uzbekistan and used structured stakeholder interviews for an expert-based assessment of potential rebound effects. Our findings contribute to the understanding of impacts of technological and institutional responses to environmental and economic pressures in sustaining water resources. The study demonstrates that although the objective of increasing irrigation efficiency may be achieved, the actual water savings under Uzbek conditions are likely to be reduced due to rebound effects. Unless there are effective policy interventions, we expect rebound effects through an increase in water supply for crops that compensates for current shortages of irrigation water availability, an increase in irrigated area, a switch to more water-intensive crops, and overall economic growth. The findings of this paper provide a reference point for estimating the water-saving potential and for evaluating and adapting policies.