The objective of the study was to improve the growing technology of grain sorghum at irrigating chernozems of the Rostov region in order to increase the yield and efficiency of reclaimed land use. For this purpose the influence of irrigation regimes and moisture availability on growth, development, and yield of grain sorghum was studied. The field experiment comprised 6 variants: 1) without irrigation; 2) maintaining soil moisture content in a soil layer of 0.6 m higher than 80 % of field capacity (FC) from emergence till the beginning of maturing (control, calculated irrigation rate, 1 m); 3) irrigation rate decreased by 20 % from the calculated irrigation rate (0.8 m); 4) irrigation rate decreased by 40 % from the calculated irrigation rate (0.6 m); 5) irrigation regime differentiated on growing phases: maintaining the soil moisture content in a soil layer of 0.6 m higher than 70 % FC from the phase of emergence till the phase of paniculation, later, up to the beginning of maturing higher than 80 % FC; 6) irrigation regime differentiated on growing phases: maintaining the soil moisture content in a soil layer of 0.6 m higher than 60 % FC from the phase of emergence till the phase of paniculation, later, up to the beginning of maturing higher than 80 % FC. The research established that at the irrigated variants sorghum plants increased their linear growth by 9-11 % against the variants without irrigation, the amount of dry mass from 1 ha increased by 47-52 %, the duration of vegetative period prolonged by 9 days; all these ultimately affected the crop yield. The highest yield of grain sorghum (13.55 t/ha) was obtained at the variant where the moisture content in a soil layer of 0.6 m maintained higher than 80 % of FC against 6.9 t/ha at the variant without irrigation . The crop yield increased by 92.5 %. The water used most efficiently, as well. So, water consumption coefficient was the least – 452 m³/t, against 714 m³/t at the variant without irrigation. The highest total water consumption 6118 m³/ha was at the variant where soil moisture content was higher than 80 % FC in a soil layer of 0.6 m, against 4928 m³/ha at the variant without irrigation.
