This may require planting deeper than 1.5 inches under dry soil conditions. If you must plant deeper than 1.5 inches in order to place the seed into uniform moisture, make sure the variety has an excellent emergence score or long hypocotyl. Also, consider seed size when deciding how deep to plant.
Sperm is made in the testes, but stored in the epididymis, a gland where it is also matured. Sperm from the testes cannot yet move on their own.
Sperm can be stored inside the male body for approximately 3 weeks after they've matured, after which they die inside the body if not ejaculated. So the entire sperm life cycle inside a man's body if not ejaculated (10 week maturation time + 3 week storage lifespan) is approximately 13 weeks or about 3 months.