There are no home test kits to analyze soil nutrients that are the slightest bit accurate or helpful. They are a waste of money. This is something that really does require a professional laboratory.

You do not need a half dozen tests - just one for the front and one for the back. Take samples from a couple of areas for each and mix them together. It would be unusual that conditions varied that widely from one area to another and for most home gardeners, there is no need to break things down into that degree of detail.

The test is also something that rarely ever needs to be repeated. What you are looking for with this process is called a "baseline" test. Once the test has revealed what your current situation is and how to correct it if necessary, it is virtually never necessary to retest unless you get carried away with amendments or fertilizers and throw things out of whack. At most, retest once every 3-5 years if you feel you must.

gardengal you said "never necessary to retest unless you get carried away with amendments or fertilizers and throw things out of whack". Have you been peeking? That's me! Here's my first test result