Extension Search / Soil Labs / Arkansas
University of Arkansas Division of Agriculture Soil Testing and Research Laboratory
University of Arkansas Division of Agriculture runs Arkansas’s public soil testing program. Send a soil sample and you get back your pH and nutrient levels, and what each number means for your plants.
Lab Details
University of Arkansas Division of Agriculture
Marianna, Arkansas
- Basic test
- Organic matter
- Nitrate
- Salts
- Micronutrients
- Texture
Open the lab's site for fees, forms and the mailing address.
Test Methods
This lab uses:
- Phosphorus: Mehlich-3. Used across much of the East, South and Midwest, on acid to neutral soils.
- Potassium: Mehlich-3. Used across much of the East, South and Midwest, on acid to neutral soils.
- Micronutrients: Mehlich-3. Used across much of the East, South and Midwest, on acid to neutral soils.
Labs pull nutrients out of soil with different chemicals, and each one gives a different number for the same soil. 20 ppm on one test and 20 ppm on another don’t mean the same thing, so check which test your report used before you compare it to a chart.
Tests
- Basic test. pH, phosphorus and potassium, usually with calcium and magnesium. Enough for most gardens and lawns.
- Organic matter. How much organic matter the soil holds, which sets how much nitrogen it releases.
- Nitrate. Nitrate nitrogen in the soil now. Most useful in dry climates, where it carries over winter.
- Salts. Soluble salts (EC), and sodium where salt or poor drainage is a problem.
- Micronutrients. Zinc, iron, manganese and copper, sometimes boron.
- Texture. Sand, silt and clay, which sets how fast water drains and how much the soil holds.
- Routine tests are free for Arkansas residents testing Arkansas soil.
- Pick up a barcoded sample box at your county Extension office, then enter the sample online before you send it.
- Drop samples at the lab or your county office. A drop box behind the lab takes samples already logged in.
- Out-of-state samples are tested for a fee.
Sources: [1] [2]
Not Tested
- Soil heavily amended with compost, bagged soil or mulch
- Potting soil, perlite or vermiculite
Out of State
This lab takes samples from other states.
Sample Tips
- Take 10 or more small cores across the area and mix them in a clean bucket. One spot tells you about one spot.
- Sample gardens and lawns about 6 inches deep, below any mulch or thatch.
- Keep beds that are grown differently, like a lawn and a vegetable garden, as separate samples.
- Wait a couple of months after fertilizing or liming, so the test reads the soil and not the last bag.
- Use the same lab and the same tests each time, so the numbers compare from year to year.
Your county Arkansas Extension office can help you take the sample and read the report.
Results
Other States
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