Fertilization by mixed seeds

In reality farmers (here in Germany) tend to "mix seed" (dunno correct english term) their fields.
Doing so means, the seedsof the intended yield (corn, wheat...) are mixed with a significant amound of seeds of a different plant (which matures/dies) before the yield. This keeps the fertilization constand without the requirement for a fruit cycle.
Ingame: Could maybe reduce yield by 20% but remove the requirement for fertilizer or fruit cycle.