21.   Some scientists believe these tunnels may serve as conduits for some plant roots.

22.   Specialists say it has become so acid that even the aluminum trapped in the clay is released, further poisoning plant roots and groundwater.

23.   Sprinkle a slow-release fertilizer, such as Osmocote, to ensure food gets to plant roots.

24.   The researchers are not sure why the soil structure changes, but suspect that it is the work of a fungus that has a symbiotic relationship with plant roots.

25.   The temperature differences cause soil to crack, exposing delicate plant roots to winter weather.

26.   These worms burrow into plant roots, and intercept nutrients moving up to the plants stems and leaves.

27.   They disperse microorganisms that attach themselves to plant roots to promote growth.

28.   This provides cover and habitat for wildlife, and plant roots filter runoff water.

29.   Walking on wet soil or working it with garden tools will compact it, making it difficult for air and water to reach plant roots.

30.   You would see water flowing horizontally underground among plant roots and fungi, pouring into animals as they fed, moving as the creatures moved.