The article presents the research results on the effectiveness of fallow lands with green manure crops as predecessors for winter wheat in reproducing the fertility of light chestnut soils, productivity and quality of winter wheat grains in organic crop farming of the Lower Volga region. The research has shown that replacing summer fallow with a fallow with phacelia as a green manure crop increases the supply of organic matter to the soil in comparison with the control variant by 3.09 t / ha, ensures a positive balance of organic matter +4.05 t / ha.