Just brewing a tea with soil is generally not the way to do it. It could work if your soil is already right with nutrients and microlife, but if that was the case you wouldn't be adding anything to that soil. Finding the right recipe for your teas is not always easy. Worm castings, microbial life, and things that encourage mycorrhiza. When doing your teas, also keep in mind that you need to add a source of food for your microbes, generally some form of sugar. I like a nutrient solution with molasses in it, I use a shot of Big Swell.