Putting compost in with mulch works just fine. You can use a drench with compost tea, mycorrhizal fungi (it's in your compost and soil, but you get a greater amount with a product like "Thrive"), molasses, etc.
Do you do any foliar feeding? That's also an excellent way to use a liquid mix (compost tea plus many other things, depending on what your goal is) in your garden.
http://www.dirtdoctor.com/Mycorrhizal-Fungi-and-Fertilizer-Efficiency_vq4610.htmhttp://www.dirtdoctor.com/Foliar-Feeding-Newsletter_vq2918.htm