The looseness of soil has a positive impact on a plant 's roots' growth in that soil, and deep burrowing earthworms improve soil porosity, water movement and plant root growth. Given these facts, deep burrowing earthworms do what to the looseness of soil for root growth among the following options:
- compact
 - improve
 - nutrients
 - destroy
 - erosion
 - support
 - decrease
 - Movement


 

  improve       