How to Read a Soil Test Report
Your soil test results arrived. Now what? This guide breaks down every number on the report so you know exactly what your lawn needs.
Overview
What You Will Learn
Soil test reports can look overwhelming — full of abbreviations, numbers, and units that mean nothing to most homeowners. But the report is actually straightforward once you know what to look for. The three most important things on any soil test are pH, phosphorus, and potassium. Everything else is secondary. This guide walks you through a typical UGA Extension soil test report line by line.
Understanding Soil pH
pH is the single most important number on your soil test. It measures how acidic or alkaline your soil is on a scale from 0 to 14, where 7.0 is neutral. Most warm-season grasses in Georgia prefer a pH between 6.0 and 6.5. Centipede is the exception — it thrives in slightly more acidic soil between 5.0 and 6.0. If your pH is below the ideal range, the report will recommend a specific amount of lime (in pounds per 1,000 square feet) to raise it. If pH is too high (rare in Georgia), the report may recommend sulfur to lower it. Getting pH right is critical because it affects how efficiently your grass can absorb every other nutrient in the soil.
pH below 5.5 means most nutrients are locked up and unavailable to your grass.
Apply lime in fall — it takes 2 to 3 months to fully adjust soil pH.
Do not add lime without a soil test — overliming can be just as harmful as acidic soil.
Phosphorus, Potassium, and the Big Three
After pH, focus on the three primary macronutrients: nitrogen (N), phosphorus (P), and potassium (K). Your soil test will show phosphorus and potassium levels directly. Nitrogen is not typically reported because it changes rapidly in the soil and does not store well. Phosphorus supports root development and is usually adequate in Georgia soils — you rarely need to add more. Potassium helps with drought tolerance, disease resistance, and overall plant health. If your report shows low potassium, your fertilizer plan should include a product with a higher K number.
Look for P and K readings — these are listed in parts per million or pounds per acre.
High phosphorus levels mean you can use a fertilizer with zero phosphorus (like 15-0-15).
Low potassium is common in sandy pockets within Georgia clay soils.
Secondary Nutrients and Micronutrients
Your report also includes calcium, magnesium, zinc, and manganese levels. In most Middle Georgia soils, calcium and magnesium are addressed by lime applications (dolomitic lime adds both). Zinc and manganese deficiencies are less common but can cause yellowing or poor growth in specific patches. If your report flags any of these as low, your lawn care provider can include targeted micronutrient applications. For most homeowners, these secondary readings confirm that your soil is in good shape — or highlight a specific deficiency that explains a stubborn problem.
Dolomitic lime supplies both calcium and magnesium while raising pH.
Iron deficiency shows as yellowing between leaf veins — common in high-pH soils.
Micronutrient issues are usually localized, not lawn-wide.
Reading the Lime and Fertilizer Recommendations
The most actionable part of your soil test report is the recommendation section at the bottom. It will list specific amounts of lime (if needed) and a suggested fertilizer analysis. Lime recommendations are given in pounds per 1,000 square feet — apply the full amount if it is 50 pounds or less. If the recommendation exceeds 50 pounds, split the application into two rounds (fall and spring). Fertilizer recommendations specify the pounds of actual nitrogen, phosphorus, and potassium your lawn needs per year. A lawn care professional can translate these numbers into a seasonal fertilization schedule tailored to your grass type.
Apply lime in the amount recommended — more is not better.
Split large lime applications (over 50 pounds per 1,000 square feet) into two rounds.
Fertilizer recommendations are for the entire year, not a single application.
Key takeaways
What to Remember
pH is the most important number — target 6.0 to 6.5 for most grasses (5.0 to 6.0 for centipede).
Phosphorus and potassium levels tell you which fertilizer analysis to use.
Nitrogen is not tested — it fluctuates too rapidly in soil.
Lime recommendations are your first action item if pH is low.
A professional can build a complete fertilization plan from your soil test results.
Common questions
Frequently Asked Questions
What is the ideal soil pH for bermuda grass?
Bermuda grass performs best at a soil pH between 6.0 and 6.5. If your soil test shows a pH below 5.8, your report will likely include a lime recommendation to raise it.
My soil test shows high phosphorus. Is that a problem?
High phosphorus is not typically harmful to your lawn, but it means you should use a fertilizer with little or no phosphorus (the middle number in the N-P-K ratio). Excessive phosphorus can run off into waterways.
How much lime should I apply based on my soil test?
Follow the exact amount recommended on your report. Apply up to 50 pounds per 1,000 square feet at once. If your report calls for more, split it into two applications separated by 3 to 4 months.
What does it mean if my potassium is low?
Low potassium reduces your lawn's ability to tolerate drought, fight disease, and recover from stress. Use a fertilizer with a higher potassium content (higher third number in the N-P-K ratio) to correct the deficiency.
Do I need a soil test every year?
Every two to three years is sufficient for most established lawns. Test sooner if you are dealing with unexplained problems, starting a new lawn, or recovering from construction.
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