The soil, paste and water tests are a comprehensive test of the mineral aspects of your soil and irrigation water. They includes the standard Mehlich 3 or AA8.2 soil test, the saturated paste test, plus an irrigation water test. Additional soil and paste tests may be ordered at the same time.

The soil test includes tests for soil pH, organic matter, Ca, Mg, K, Na, P, S, B, Fe, Mn, Cu, Zn and Al as well as the calculated TCEC and percentage base saturation of the cations, Ca, Mg, K and Na. It also includes an additional test for soil reserves of Co, Mo, Se and Si and the electrical conductivity (EC) of the soil as well as ammonium nitrogen and nitrate nitrogen levels.

The saturated paste test is a test for suluble minerals in the soil. It includes tests for pH, soluble salts, chloride, bicarbonate, S, P, Ca, Mg, K, Na, B, Fe, Mn, Cu, Zn and Al using water as the solvent.  This test identifies the amount of soluble nutrients present in the soil.  It is a test for short term availability of nutrients.  If you irrigate, always supply irrigation water to the lab for this test.

The irrigation water suitability test includes pH, hardness, conductivity, SAR, Ca, Mg, K, Na, Fe, B, P, nitrate, total alkalinity, carbonate, bicarbonate, chloride, sulfate and salt concentration. This is a good test to identify any potential problems with irrigation water that may need to be addressed.  It is very useful in conjunction with the saturated paste test using the same water, since it helps to identify the source of soluble nutrients.

The irrigation water monitoring test is the same test as the irrigation water suitability test except it does not include tests for phosphorus and nitrate.  Also, adjusted SAR and pHc are not calculated. If your water is not likely to be contaminated by runoff from agricultural operations, the irrigation monitoring test is recommended.

Is your soil fizzy? Before you order you will need to do a fizz test on your soil. This will tell you which type of soil test to get – either the standard Mehlich 3 or AA 8.2 for fizzy soil. Easy instructions for how to do a fizz test are here.

How does it work? When your order is complete we email you a form to send with your soil sample. You will need to sample your soil (here’s how to take a soil sample) and mail the sample to Logan Labs. Logan Labs tests the sample and we email the soil, paste and water test reports to you.

How long does it take? It usually takes about 3 to 5 working days after your samples are received at Logan Labs before you receive your soil and water test reports. In the spring the lab is busier and it may take longer. Logan shuts down for major holidays and the week between Christmas and New Years.