The looseness of soil has a positive impact on a plant 's roots' growth in that soil, and to improve soil, add several top-dressings of dirt or compost. Given these facts, what has a positive impact on a plant's roots' growth among the following options:
- reducing acid rain
 - color of dirt
 - looseness of dirt or compost
 - basic building blocks of life
 - biological diversity
 - lead in the soil
 - Evaporation of water
 - a lack of soil


 

   looseness of dirt or compost      