Abstract
Questions of reuse of drainage water and wastewater of rice systems on the example of rice irrigation systems are determined. The technological scheme, which saves water and energy resources during the irrigation of crops in the rice system, is proposed. Calculations of economic efficiency of water circulation technology in the Danube rice irrigation systems (RIS) with drainage water and wastewater (DWW) dilution with fresh water in the ratio of 1 : 1 showed that the net profit will amount to UAH 26,266.5 per 1 ha, while the dilution in the ratio of 1 : 2 – to UAH 26,161.5 per 1 ha. Complementary net profit will accordingly amount to UAH 1,337.8 and 1,231.5 per 1 ha. The most perspective technique to use DWW in rice irrigation systems is their reuse with dilution with fresh water at a ratio of 1 : 1 or 1 : 2. This ratio corresponds to most indicators for which was done an evaluation of water that is supplied for irrigation. Also this ratio does not lead to deterioration of soil salt regime.