The purpose of the research is the calculation of the grain maize irrigation rate during drip irrigation (by the example of Semikarakorsk district of Rostov region). While carrying out the research, the methodological approaches by O. E. Yasonidi, V. S. Mezentsev, A. I. Golovanov, G. A. Senchukov were used. A brief review of advantages and experience of drip irrigation application in a number of countries of the world is made. The optimal scheme of crop sowing was chosen, distances between emitters and between drip laterals were specified, the total number of emitters on the irrigation area with regard for the watering area and plants’ nutrition area were calculated. To determine the design irrigation rate of grain maize under drip irrigation under the conditions of Semikarakorsk district of Rostov region the following calculations were done: evapotranspiration of grain maize based on bioclimatic coefficients and rainfall, evaporation in the zone of natural moisture and evaporation, stored soil moisture as of the date of the beginning and end of the vegetation period, the moisture content in the calculated layer of moistured and non-moistured zone of nutrition area, shortage of water consumption per plant and per hectare. The calculated values of modular coefficients of the set level of availability were obtained: for wet, medium-wet, medium-dry and extremely dry years. The calculation of all main parameters was completed for the conditions of the middle and extremely dry years by the degree of heat and moisture supply. It has been found that by maize cultivation under the soil and climatic conditions of Semikarakorsk district Rostov region the plants begin to suffer from a deficit of water consumption from the second decade of June, reaching a maximum in the third decade of July: 225 m cubic per ha in the mean year and 378 m cubic per ha in a very dry year. Drip irrigation of grain maize makes it possible to reduce the irrigation water consumption by 49–58 %, which ensures its considerable saving under conditions of its deficit.
Key words: drip irrigation, grain maize, heat and moisture supply, water consumption deficit, irrigation rate.
