nice!

creative.. good job

The tap needs a shadow too. The source you linked to is from a blog, and not usable. This one is: http://www.sxc.hu/photo/814397

I put shadow but,it is very little part of the shadow,behind the tree!
I did't know for that pic,can you exp me,why!

Idea is very interesting. But consider that when water reaches a dry soil, what color is the soil when wet? Dark brown or dark red (it depends on the type of the soil).

The shadow cast of the tap must have the same color as the shadow cast of the tree.The easiest way to do this is clone stamp inside the shadow selection with source on the tree selection.