Corn (Zea mays L.) is one of the most commonly planted agricultural crop in the world. It is used as a feed for livestock, for human consumption and as a raw material in various industries. Corn quality evaluation is based on the genetic components of the yield and chemical composition of the grain. The aim of this study was to examine the effectiveness of a different beneficial technologies microorganism preparations with irrigation and fertilization as well as without any treatment of the crop and the basic properties of grain of maize hybrid OSSK 499. The grain samples were collected during the harvest, afterwards they were subjected to the analysis of protein, oil, moisture and starch content and determination of the hectolitre weight. The highest yield of 13140 kg/ha was achieved during rational irrigation, including fertilization with 100 kg/ha of nitrogen and without beneficial microorganisms use. The highest hectolitre weight of 79 kg was recorded in corn grown with the rich irrigation, fertilization with 200 kg/ha of nitrogen and without the beneficial microorganism 1 application. The highest moisture content was found in the grain of the corn grown without fertilizers, with abundant irrigation and without beneficial microorganism treatment. The highest protein content was recorded in the corn grown without irrigation, but with fertilization with 200 kg/ha of nitrogen and under treatment with beneficial microorganism. The highest oil content was found in the corn grown without irrigation and fertilization, but with beneficial microorganism 3. Corn grown with rational irrigation, without fertilizer addition or beneficial microorganisms use had the highest starch content. From the above-mentioned, it can be concluded that the use of the beneficial microorganisms had the greatest impact on the protein and oil content in the corn grain.