Any experienced farmer knows he must keep his soils well fertilized; and to do that, he must depend on soil testing laboratories to inform him of his fertilizing needs. Standard soil testing is available in all fifty states through land-grant universities and commercial soil testing services.
Soil testing equipment varies from lab to lab, but generally a standard soil test provides information on soil nutrient levels of nitrogen, phosphorus, potassium, calcium and magnesium. Testing soil pH is also part of a standard soil test.
As you look for a soil testing lab, you should consider the following:
1. The types of soil testing done by the lab.
2. How to use the soil testing kits provided by the lab.
3. Whether the soil evaluation is correct for your soil.
Know the type of soil analysis you needSoil testing laboratories can provide information on your local soil types, and tell you what you need to keep the soil fertilized. But you need to know what you're looking for. Rather than run expensive broad-spectrum tests, you may only need to do specific tests. Also, find soil testing laboratories that offer fast, reliable service.
Ohio State University offers a simple checklist of things you should look for from soil testing laboratories. Virginia Tech offers a list for farmers and gardeners to help them get the correct soil evaluation.
Use the right soil testing equipmentThe soil testing lab can only do so much with an improperly taken soil test. Contact the lab to get the correct directions for the type of testing that they perform. Typically, you need to take soil samples from several areas of a field in order to get a viable soil sample. Each sample should come from a specific depth. You also need to handle the soil sample in the right manner for optimal test results.
The University of Massachusetts gives you a list of specific soil tests and their costs. The University of Minnesota offers a similar list on theirs.
Get the right soil analysis for organic farmingOrganic tests should include content analysis for soil humus, organic matter, microbial matter and compost. This kind of test helps insure total soil health, rather than a test that emphasizes minerals alone. If you're farming organically be sure your lab can meet your specifications.
The National Sustainable Agriculture Information Service offers a guide to organic soil testing. Texas Plant and Soil Lab (TPSL) offers all types of soil testing for organic farms. Oregon State University offers soil testing for small farms focused on organic farming.
- Use a soil testing lab near you for the best results. Check with your local cooperative extension service for a list of soil testing laboratories in your area. Find one that's independent from any fertilizer company ties in order to get the most unbiased results.