How does smoking effect spermatogenesis?

Negatively. Smoking has negative impact on spermatogenesis.The effect is noticed but not well studied.
Here are some... The idea of smoking negativity on spermatogenesis is drawn from indirect evidence by collecting and analyzing the experience in men with or without smoking; likewise, all medical care is based on indirect evidence. As to how? Most of times, the exact reason for associated effect could not be elucidated. To explore how to live a long happy life, go to http://formefirst.com/eMagicPowerUHL.html.