Hi Fara,
While you can put your kitchen scraps in a hole or trench and cover it with soil to add nutrients to the soil and create ‘compost’ much faster than if it was in a compost heap, you want to keep the buried food scraps a little distance from the current plants that you have going. This is because the decomposition and breakdown of the food scraps will take nitrogen from the soil immediately around it.
All in all food scraps wouldn’t make the best mulch.
With warmth,
Benna