How is compost better than liquid manure?

Because finished compost is a dry material (typically less than 50% moisture at maturity, it is less costly to spread than wet manure (typically 75-95% water). Finished compost is odorless and the nutrients it contains are much less mobile under rainfall conditions than manure.  In fact, compost is often used as an erosion control material to help prevent soil movement on disturbed sites. Properly composted material does not contain viable weed seeds, which liquid manure often does, so spreading compost does not spread thistles or other weeds.