Acta Scientiarum Polonorum

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.