Advanced Soil Health Test Cost Estimator

For representative samples:

• Use clean tools (stainless steel probe or shovel)
• Sample at consistent depth (usually 6-8″ for crops)
• Take multiple subsamples (15-20) per homogeneous area
• Avoid unusual spots (near fences, compost piles)
• Mix subsamples thoroughly in a clean container
• Send about 1-2 cups of mixed soil to the lab

Different areas (lawn vs garden) should be sampled separately.

These are different chemical extraction methods used to estimate plant-available nutrients:

Mehlich-3: Acid-based extractant that works well for acidic to neutral soils. Measures a wider range of nutrients simultaneously (P, K, Ca, Mg, plus micronutrients). More common in eastern and southern US.

Olsen (Bicarbonate): Alkaline extractant best for neutral to alkaline soils (pH >7). Particularly good for phosphorus in calcareous soils. More common in western states.

Always check which method your lab uses, as results aren’t directly comparable between methods.

Microbial testing (PLFA analysis or DNA sequencing) provides value when:

• Diagnosing persistent plant health issues with no clear nutrient cause
• Monitoring soil health improvement over time in regenerative systems
• Assessing compost or inoculant effectiveness
• Researching specific plant-microbe interactions
• Transitioning to organic production

For most annual testing, standard chemical tests combined with organic matter measurement are sufficient.

Base saturation shows the proportion of your soil’s CEC occupied by each cation:

• Calcium (Ca): Ideal range 65-75% for most crops
• Magnesium (Mg): 10-15% (Ca:Mg ratio ~7:1)
• Potassium (K): 2-5%
• Sodium (Na): Below 1%
• Hydrogen (H): Indicates acidity

Imbalances can affect soil structure and nutrient availability. For example, high Mg can cause compaction, while excessive K can inhibit Ca uptake.