Knowledge Base

Identification code


Project title

Study of the balance of nutrients and their washing out with drainage water (pilot plot in Niyazov collective farm, Akhunbabayev rayon, Fergana province)

Project site

Republic of Uzbekistan, Fergana province, Akhunbabayev rayon, Niyazov collective farm


70.03.15; 70.03.21

Rubric (SIC ICWC);

Project duration


Project manager

Khaldar Yakubov, SPA SANIIRI

Karasu 4/11, Tashkent, 700187, Republic of Uzbekistan


The study dealt with the following issues:- increase of irrigated land productivity when using chemical fertilizers through the optimal combination of the scope and the work schedules for hydroreclamation and agrotechnical measures;- identification of links between the water, temperature regime of soil, dates and rates of fertilization and the mineral nitrogen migration in irrigated lands;- establishment of regularities in nitrogen transformation depending on moisture and temperature. According to natural and economic characteristics this pilot plot is typical for Central Fergana. Soil texture is medium and light loam. Gypsum layers are located at 1-2,5 m. The soils are low saline, chemical composition is chloride-sulphate. Water table during growing period is 1,4-2,5 m, while it is 2,8 m during non-growing period. Groundwater salinity is 3,6-4,6 g/l.The pilot plot area - 9 ha.The plot was equipped with necessary measuring devices.

Analysis and processing of obtained research results allowed to establish regularities characterizing the process of nitrogen transformation in soil with regard for soil moisture and temperature, and to obtain qualitative characteristics of this process. Calculation methods for mineral nitrogen balance in the root zone and the aeration zone were developed. It was established, that the amount of nitrogen in drainage effluent is in direct proportion to mineral nitrogen fertilization. Optimal dates and doses of chemical fertilization were determined.

Key words

Soils, water regime, fertilizer, drainage flow


O.M.Belousov, Kh.UmarovDevelopment of zonal recommendations on soil water-salt regime regulation, which provide the increase of irrigated land productivity under water scarcity and deterioration. Tashkent, 1997.

The publication contains analysis of laboratory studies and research on the migration and transformation of nutrients in soil, mathematical models for water and nutrients migration in irrigated soils, and calculation methods for mineral nitrogen balance in root and aeration zones.