The main purpose of the research is to develop rational irrigation regime and water consumption for maize in combination with various doses of mineral nutrition providing high yields at the light chestnut soils of Volgograd region. The coefficients of water consumption and costs of irrigation water for maize are presented. The conducted study has shown that a significant influence on the dynamics of the maize water consumption coefficient has water regime of soil in combination with an appropriate level of mineral nutrition. It is established that irrigation rate is the main item in the structure of total water consumption. The part of irrigation water for moistening soil layer of 0.4 m is 54.0 % in average; and it enlarges up to 59.9 % while the soil layer depth increases to 0.7 m. The part of irrigation water for differentiated depth of irrigated soil layer of 0.4-0.7 m varies from 47.3 to 69.0 %. Based on the results of the research, it can be noted that the efficiency of irrigation water use increased in variants with differentiated depth of irrigated soil layer due to the increase of maize yield. The highest yield was in 2006. Depending on the depth of irrigated soil layer, the yield of maize varied from 6.10 up to 9.57 t/ha which was higher by 5.1-12.3 % than in 2004. The various doses of fertilizers applied also have an impact on maize yield. The fertilizer dose N150P140K60 kg/ha provided higher yield (in average for the 2004-2005) which varied from 7.95 to 9.32 t/ha.
Keywords: maize, yield, water consumption coefficient, water costs, depth of irrigated soil layer, fertilizer dose.
