The article presents the results of studying the addition of green mass of grass to the flattened spring barley grain. Finely chopped grass is an effective means of accelerating the creation of anaerobic conditions in the grain mass and reducing the loss of dry matter during storage. It was revealed that as a result of the addition of grass, the period of creating oxygen-free conditions had been reduced to two or three days, the loss of dry matter during this time had not exceeded 1.5-2.5%. The optimal dose of grass has been 3% of the grain weight.