Complex sentence: The surface conditions are influenced by the type of surface factoring in soil type, and if the track is dirt, turf, artificial surface; plus surface density, porosity, compaction and moisture content.
Split into simpler sentences: The surface conditions are influenced by the type of surface. A major factor is soil type, and if the track is made up of dirt, turf, or some type of artificial surface; plus surface density, porosity, compaction and moisture content.