The results of the study of changes in winter wheat grain yield depending on the rotation length of crop rotations in the Lower Volga region are presented. As a result of 12 years of research (20082019) it was found that the maximum yield was obtained in four- and five-field crop rotations with the inclusion of leguminous crops - 2.73 and 2.79 t/ha, respectively. During the analysis of variance, different effects of growing conditions and rotation length on winter wheat yields were noted. The influence of vegetation conditions accounted for 98.6%. The effect of crop rotation was also significant (0.6%). Winter wheat grain yield significantly depended on the weather conditions, which allowed to fully evaluate the potential of winter wheat - fallow in crop rotations with a short rotation. When winter wheat was cultivated in four- and five-field crop rotations with the inclusion of leguminous crops, the yield increased both in wet and moderately wet years. With HTC greater than 0.9 in the five-field crop rotation the grain yield was 4.40 t/ha, in four-field - 4.31, in three-field - 4.02 t/ha. With HTC of 0.6 to 0.9 in four- and five-field crop rotations, the yield ranged from 2.78-2.84 t/ha, and in three-field crop rotations it was 2.52 t/ha. In dry years, no significant difference in winter wheat yield between crop rotations was found, which ranged from 0.98-1.07 t/ha. It can be concluded that winter wheat cultivation on the second field of short rotational crop rotations on fallow preceding crop in conditions of insufficient moisture is effective.