This can be a dilema for many gardeners because as they increase the level of organic matter in their soil the also see an increase in insect pests, such as slugs. But they don't seem to notice the increase in the beneficial insect population that will help control the pest types, or the increase in other predators that also help control the pests, thing such as toads, birds, and even snakes.
As your soils health improves so will the total ecosystem and a balance will be acheived were the insect pest population will be controlled by the beneficial insect population.
In the meantime, if its necessary, you can keep the slugs from eating plants by spraying them with cold, caffienated, coffee.

kimmsr, do you spray the plants with coffee?

As necessary. After I read this report about the research done at the USDA Field Station in Hilo, Hawaii I thought hmmm and put some of my leftover, cow cold, morning coffee in a spray bottle and looked for slugs. Many were under the bird bath and I sprayed them, directly, with this cold coffee and slugs never moved so fast before, or since. and they wriggled and squirmed and did not return to that bird bath the rest of the summer. So one the rare occassion I see some slug damage on a plant I spray it with cold, caffienated coffee and the damage stops.