The U of Idaho "Extension" office has many links related to soil testing. It looks like Ada county makes it easier than other counties, but you can get contact info for your county, then call someone local and ask them what's the least expensive way to get a soil test done. (Your local extension agent if a good person to maker a friend of.)
Ada County also has many free clinics.
http://extension.uidaho.edu/ad...
University of Idaho soil test: $35.00 (Our office provides soil test kits; the test is sent by the customer to the U of I.)
How to collect a representative soil sample:
http://www.cals.uidaho.edu/edc...
USING soil test results:
http://www.cals.uidaho.edu/edc...
UI Extension Home Page
http://www.uidaho.edu/extensio...
Extension Office Contact Info for your county:
County: Kootenai County Extension Office
Address: 1808 North 3rd. Street
Coeur d'Alene, ID 83814-3407
Phone: (208) 446-1680
Fax: (208) 446-1690
Email:
[email protected]
Web Address: http://extension.uidaho.edu/kootenai/