An optimization of seed planting depth at different sowing dates of a soybean

«OIL CROPS» Scientific bulletin, VNIIMK, 2006, is 2 (135). Basing on the field trial results of 2004-2006 conducted on leached superdeep chernozem of central experimental base of VNIIMK a possibility and efficiency to plant soybean seed on depth 10-12 sm., especially for late sowing dates when upper (6-8 sm.). soil layer is over-dried, is substantiated. The early mature cultivar Lira was more susceptible on seeds deepening in these years in comparison with middle mature cultivar Vilana. An effectiveness of soybean seed deepening in planting, on impact on productivity process, depends significantly on weather conditions during vegetative period. Yield of the both cultivars were substantially lower in June planting than in May planting on all studied seed sowing depths.