Crop diversification in support of sustainable agriculture in Khorezm

Abstract

Escalating soil degradation caused by soil salinity and rising saline groundwater tables, limits crop production in the irrigated lowlands of arid Uzbekistan. Crop diversification is one option for obtaining more stable farm incomes while improving natural resource use and environmental sustainability. Although the agro-climatic conditions in the country allow growing a wide variety of crops, few crops (cotton, winter wheat, rice, maize) dominate the crop portfolio, which also reflects the restrictions imposed by the state. In the Khorezm region in northwest Uzbekistan, we examined the economic and ecological suitability of alternative crops in a stepwise approach. A literature review resulted in a list of about 30 crops that would theoretically fit the agro-climatic conditions in this region. For field research, five crops with a high potential were selected based on socio-economic (potential income) and bio-physical (potential yield, crop quality, options for soil improvement, water use efficiency) criteria. The crops included sorghum (Sorghum bicolor (L.) Moench), potato (Solanum tuberosum), the cash crop indigo (Indigofera tinctoria), and the food and feed crops mung bean (Vigna radiata) and sweet maize (Zea Mays L.). Field experiments were complemented with laboratory analyses and mathematical modeling for estimating the potential economic and ecological benefits from these crops. Three potato varieties from Germany out-yielded the local variety by at least 50%. Sorghum, indigo, maize and mung bean grew well on marginal lands and obtained very high revenues. Findings from the simulation runs demonstrate that crops such as maize for grain, potato and fodder crops could play an important role in coping with risks in drought years and for securing farm income. Field experiments and modeling results based on this extensive data set from Khorezm allow upscaling to regions in Central Asia with similar agro-climatic conditions.